Contemporary sediment-transport processes in submarine canyons.

Science.gov (United States)

Puig, Pere; Palanques, Albert; Martín, Jacobo

2014-01-01

Submarine canyons are morphological incisions into continental margins that act as major conduits of sediment from shallow- to deep-sea regions. However, the exact mechanisms involved in sediment transfer within submarine canyons are still a subject of investigation. Several studies have provided direct information about contemporary sedimentary processes in submarine canyons that suggests different modes of transport and various triggering mechanisms. Storm-induced turbidity currents and enhanced off-shelf advection, hyperpycnal flows and failures of recently deposited fluvial sediments, dense shelf-water cascading, canyon-flank failures, and trawling-induced resuspension largely dominate present-day sediment transfer through canyons. Additionally, internal waves periodically resuspend ephemeral deposits within canyons and contribute to dispersing particles or retaining and accumulating them in specific regions. These transport processes commonly deposit sediments in the upper- and middle-canyon reaches for decades or centuries before being completely or partially flushed farther down-canyon by large sediment failures.

Submarines, spacecraft and exhaled breath.

Science.gov (United States)

Pleil, Joachim D; Hansel, Armin

2012-03-01

extend the underwater endurance to 2-3 weeks. These propulsion engineering changes also reduce periodic ventilation of the submarine's interior and thus put a greater burden on the various maintenance systems. We note that the spaceflight community has similar issues; their energy production mechanisms are essentially air independent in that they rely almost entirely on photovoltaic arrays for electricity generation, with only emergency back-up power from alcohol fuel cells. In response to prolonged underwater submarine AIP operations, months-long spaceflight operations onboard the ISS and planning for future years-long missions to Mars, there has been an increasing awareness that bio-monitoring is an important factor for assessing the health and awareness states of the crewmembers. SAMAP researchers have been proposing various air and bio-monitoring instruments and methods in response to these needs. One of the most promising new methodologies is the non-invasive monitoring of exhaled breath. So, what do the IABR and SAMAP communities have in common? Inhalation toxicology. We are both concerned with contamination from the environment, either as a direct health threat or as a confounder for diagnostic assessments. For example, the exhaled breath from subjects in a contaminated and enclosed artificial environment (submarine or spacecraft) can serve as a model system and a source of contamination for their peers in a cleaner environment. In a similar way, exhaled anaesthetics can serve as a source of contamination in hospital/clinical settings, or exhalation of occupational exposures to tetrachloroethylene can impact family members at home. Instrumentation development. Both communities have similar needs for better, more specific and more sensitive instruments. Certainly, the analytical instruments to be used onboard submarines and spacecraft have severe restrictions on energy use, physical size and ease of operation. The medical and clinical communities have similar long

Submarine tectonic relief off Enshunada. Enshunadaoki no hendo chikei

Energy Technology Data Exchange (ETDEWEB)

Iwabuchi, Y; Sasahara, N; Hamamoto, F [Maritime Safety Agency, Tokyo (Japan); Yoshioka, S [10th Resional Maritime Safety Headquarters, Kagoshima (Japan); Kondo, T [Maritime Safety School, Kyoto (Japan)

1991-08-15

This paper reports on the results of investigations on the submarine relief structure off the Enshunada (a sea area which is on the south of the Tenryu River mouth and has about 50km east and west and about 100km north and south) using a bathymetric surveying ship equipped with a narrow multibeam echo sounder. The submarine relief structure of this sea area is clarified into the following topographical districts arranged north to south (each extends roughly in the northeast-southwest direction): the Enshu trough and Tenryu submarine canyon upper valley located in the center thereof, ridges represented by No.l and No.2 Tenryu knolls, the ridge and trough zone where minor ridges and troughes appear complicatedly and repeatedly, and the Nankai trough. The paper contains causes of formation of the Tenryu submarine canyon, the Ryuyo submarine canyon which is located in the northwestern slope of No.2 Tenryu knoll and has a distinct shape, oval-shaped domes scattered in the bottom of Nankai trough, etc. and also opinions on landslide topography seen in the ridge and trough zone. 13 refs., 5 figs., 1 tab.

Acute Exposure to Low-to-Moderate Carbon Dioxide Levels and Submariner Decision Making.

Science.gov (United States)

Rodeheffer, Christopher D; Chabal, Sarah; Clarke, John M; Fothergill, David M

2018-06-01

Submarines routinely operate with higher levels of ambient carbon dioxide (CO2) (i.e., 2000 - 5000 ppm) than what is typically considered normal (i.e., 400 - 600 ppm). Although significant cognitive impairments are rarely reported at these elevated CO2 levels, recent studies using the Strategic Management Simulation (SMS) test have found impairments in decision-making performance during acute CO2 exposure at levels as low as 1000 ppm. This is a potential concern for submarine operations, as personnel regularly make mission-critical decisions that affect the safety and efficiency of the vessel and its crew while exposed to similar levels of CO2. The objective of this study was to determine if submariner decision-making performance is impacted by acute exposure to levels of CO2 routinely present in the submarine atmosphere during sea patrols. Using a subject-blinded balanced design, 36 submarine-qualified sailors were randomly assigned to receive 1 of 3 CO2 exposure conditions (600, 2500, or 15,000 ppm). After a 45-min atmospheric acclimation period, participants completed an 80-min computer-administered SMS test as a measure of decision making. There were no significant differences for any of the nine SMS measures of decision making between the CO2 exposure conditions. In contrast to recent research demonstrating cognitive deficits on the SMS test in students and professional-grade office workers, we were unable to replicate this effect in a submariner population-even with acute CO2 exposures more than an order of magnitude greater than those used in previous studies that demonstrated such effects.Rodeheffer CD, Chabal S, Clarke JM, Fothergill DM. Acute exposure to low-to-moderate carbon dioxide levels and submariner decision making. Aerosp Med Hum Perform. 2018; 89(6):520-525.

Search Problems in Mission Planning and Navigation of Autonomous Aircraft. M.S. Thesis

Science.gov (United States)

Krozel, James A.

1988-01-01

An architecture for the control of an autonomous aircraft is presented. The architecture is a hierarchical system representing an anthropomorphic breakdown of the control problem into planner, navigator, and pilot systems. The planner system determines high level global plans from overall mission objectives. This abstract mission planning is investigated by focusing on the Traveling Salesman Problem with variations on local and global constraints. Tree search techniques are applied including the breadth first, depth first, and best first algorithms. The minimum-column and row entries for the Traveling Salesman Problem cost matrix provides a powerful heuristic to guide these search techniques. Mission planning subgoals are directed from the planner to the navigator for planning routes in mountainous terrain with threats. Terrain/threat information is abstracted into a graph of possible paths for which graph searches are performed. It is shown that paths can be well represented by a search graph based on the Voronoi diagram of points representing the vertices of mountain boundaries. A comparison of Dijkstra's dynamic programming algorithm and the A* graph search algorithm from artificial intelligence/operations research is performed for several navigation path planning examples. These examples illustrate paths that minimize a combination of distance and exposure to threats. Finally, the pilot system synthesizes the flight trajectory by creating the control commands to fly the aircraft.

Submarine hydrodynamics

CERN Document Server

Renilson, Martin

2015-01-01

This book adopts a practical approach and presents recent research together with applications in real submarine design and operation. Topics covered include hydrostatics, manoeuvring, resistance and propulsion of submarines. The author briefly reviews basic concepts in ship hydrodynamics and goes on to show how they are applied to submarines, including a look at the use of physical model experiments. The issues associated with manoeuvring in both the horizontal and vertical planes are explained, and readers will discover suggested criteria for stability, along with rudder and hydroplane effectiveness. The book includes a section on appendage design which includes information on sail design, different arrangements of bow planes and alternative stern configurations. Other themes explored in this book include hydro-acoustic performance, the components of resistance and the effect of hull shape. Readers will value the author’s applied experience as well as the empirical expressions that are presented for use a...

Nuclear submarine utilization. Financial deadlock and search for its output

International Nuclear Information System (INIS)

Dovgusha, V.V.; Tikhonov, M.N.

1995-01-01

Program of nuclear submarine utilization in the Russian Federation is described. The program provides for complete solution of all problems, connected with nuclear submarine utilization, including reconstruction of ship-repair and ship-cutting plants, metal fabrication plants, construction of points of temporary radioactive waste storages, new burials, as well as required social support of personnel, working under unhealthy conditions. The program is based on guaranteed and sufficient financing from extra-budgetary sources, as well as on new technologies, enabling to utilize all written off ships during 10-15 years

The Italian Submarine Force in the Battle of the Atlantic: Left in the Dark

Science.gov (United States)

2014-12-12

ADM Admiral ASW Anti-submarine warfare BDA Battle damage assessment C2 Command and Control CDR Commander HF/DF High frequency direction finder...damage assessment ( BDA ) if you will, the submarine captain decided if further action might be warranted, and made a decision as to how to engage

Changes in body composition of submarine crew during prolonged submarine deployment

Directory of Open Access Journals (Sweden)

Sourabh Bhutani

2015-01-01

Discussion: Increased body fat along with lack of physical activity can lead to development of lifestyle disorders in submarine crew. These crew members need to be actively encouraged to participate in physical activity when in harbour. In addition dieting program specifically to encourage reduced fat consumption needs to be instituted in submarines during sorties at sea.

Health Risks Among Submarine Personnel in the U.S. Navy, 1974-1979

Science.gov (United States)

1986-12-11

observed dif- ferences in hospitalization rates ( Lilienfeld , 1980). T- tests were used to assess statistical significance of the descriptive variables...the direct method of adjustment ( Lilienfeld , 1980). The standard population was the sum of the two groups. Age-adjusted rates for submariners and...must undergo stringent psychological and medical screening prior to assignment aboard a nuclear submarine because of the relatively long periods of

Mission-directed path planning for planetary rover exploration

Science.gov (United States)

Tompkins, Paul

2005-07-01

Robotic rovers uniquely benefit planetary exploration---they enable regional exploration with the precision of in-situ measurements, a combination impossible from an orbiting spacecraft or fixed lander. Mission planning for planetary rover exploration currently utilizes sophisticated software for activity planning and scheduling, but simplified path planning and execution approaches tailored for localized operations to individual targets. This approach is insufficient for the investigation of multiple, regionally distributed targets in a single command cycle. Path planning tailored for this task must consider the impact of large scale terrain on power, speed and regional access; the effect of route timing on resource availability; the limitations of finite resource capacity and other operational constraints on vehicle range and timing; and the mutual influence between traverses and upstream and downstream stationary activities. Encapsulating this reasoning in an efficient autonomous planner would allow a rover to continue operating rationally despite significant deviations from an initial plan. This research presents mission-directed path planning that enables an autonomous, strategic reasoning capability for robotic explorers. Planning operates in a space of position, time and energy. Unlike previous hierarchical approaches, it treats these dimensions simultaneously to enable globally-optimal solutions. The approach calls on a near incremental search algorithm designed for planning and re-planning under global constraints, in spaces of higher than two dimensions. Solutions under this method specify routes that avoid terrain obstacles, optimize the collection and use of rechargable energy, satisfy local and global mission constraints, and account for the time and energy of interleaved mission activities. Furthermore, the approach efficiently re-plans in response to updates in vehicle state and world models, and is well suited to online operation aboard a robot

Submarine Salt Karst Terrains

Directory of Open Access Journals (Sweden)

Nico Augustin

2016-06-01

Full Text Available Karst terrains that develop in bodies of rock salt (taken as mainly of halite, NaCl are special not only for developing in one of the most soluble of all rocks, but also for developing in one of the weakest rocks. Salt is so weak that many surface-piercing salt diapirs extrude slow fountains of salt that that gravity spread downslope over deserts on land and over sea floors. Salt fountains in the deserts of Iran are usually so dry that they flow at only a few cm/yr but the few rain storms a decade so soak and weaken them that they surge at dm/day for a few days. We illustrate the only case where the rates at which different parts of one of the many tens of subaerial salt karst terrains in Iran flows downslope constrains the rates at which its subaerial salt karst terrains form. Normal seawater is only 10% saturated in NaCl. It should therefore be sufficiently aggressive to erode karst terrains into exposures of salt on the thousands of known submarine salt extrusions that have flowed or are still flowing over the floors of hundreds of submarine basins worldwide. However, we know of no attempt to constrain the processes that form submarine salt karst terrains on any of these of submarine salt extrusions. As on land, many potential submarine karst terrains are cloaked by clastic and pelagic sediments that are often hundreds of m thick. Nevertheless, detailed geophysical and bathymetric surveys have already mapped likely submarine salt karst terrains in at least the Gulf of Mexico, and the Red Sea. New images of these two areas are offered as clear evidence of submarine salt dissolution due to sinking or rising aggressive fluids. We suggest that repeated 3D surveys of distinctive features (± fixed seismic reflectors of such terrains could measure any downslope salt flow and thus offer an exceptional opportunity to constrain the rates at which submarine salt karst terrains develop. Such rates are of interest to all salt tectonicians and the many

Low cost submarine robot

Directory of Open Access Journals (Sweden)

Ponlachart Chotikarn

2010-10-01

Full Text Available A submarine robot is a semi-autonomous submarine robot used mainly for marine environmental research. We aim todevelop a low cost, semi-autonomous submarine robot which is able to travel underwater. The robot’s structure was designedand patented using a novel idea of the diving system employing a volume adjustment mechanism to vary the robot’s density.A light weight, flexibility and small structure provided by PVC can be used to construct the torpedo-liked shape robot.Hydraulic seal and O-ring rubbers are used to prevent water leaking. This robot is controlled by a wired communicationsystem.

Analysis of SSN 688 Class Submarine Maintenance Delays

Science.gov (United States)

2017-06-01

Simplified Notional Submarine FRP (Independent Deployer) ..................11  Figure 8.  Evolution of Los Angeles Class Submarine Notional...Number TFP Technical Foundation Paper URO Unrestricted Operations xv ACKNOWLEDGMENTS I would like to thank my lead advisor, Professor Nick Dew...only on Los Angeles (SSN 688)-class submarines. Being the higher quantity and older generation submarine hull type, the Los Angeles class submarine

Research on Fairing design and CFD Analysis of Submarine Pipeline Inspection ARV

Directory of Open Access Journals (Sweden)

Jin Xiaojian

2017-01-01

Full Text Available Along with the fast development of the ocean exploitation, the cost-effective requirement of autonomous & remotely operated vehicle (ARV, which can perform more complicated missions such as the oil exploitation and the inspection of the submarine pipeline is more urgent. The submarine pipeline inspection ARV can help us better understand, protect and efficiently utilize them for human welfare. Fairing design of a new detection ARV are introduced in this paper. In order to select an appropriate thruster that will achieve the required speed of the ARV, the ANSYS-CFX tools are used to predicted the drag force. The CFD results reveal the distribution of velocity and pressure values of the ARV. In order to verify the CFD modeling process, a towed body was developed and analyzed, compared against the corresponding physical test data.

The use of nuclear powered submarines for oceanographic research in ICE covered regions

International Nuclear Information System (INIS)

Sambrotto, Raymond; Chayes, Dale

2000-01-01

unsurpassed platform for sea ice and geological and geophysics measurements because remote sensing of important properties in these disciplines is possible. Thus, the submarine was able to collect sea ice thickness and the topography and other characteristics of the bottom almost continuously along track, expanding available data for some of these parameters several fold. The mobility and extended duty period of nuclear submarines complement observations from surface ships and satellite sensors. Although the submarines were used without significant engineering modifications, improved sampling devices could overcome many of the limitations imposed by their restricted depth ranges. The continuing availability of dedicated science missions on military submarines is uncertain due to the reduced fleet size. However, even science measurements made on an ancillary basis during non-science cruises to ice covered seas would be highly informative. The Scicex program demonstrated that nuclear submarines are able to provide a unique observational platform for scientific measurements in ice covered seas that can be used for both basic and applied research. (author)

Nonverbal behavior observation : collaborative gaming method for prediction of conflicts during long-term missions

NARCIS (Netherlands)

Voynarovskaya, N.; Gorbunov, R.D.; Barakova, E.I.; Ahn, R.M.C.; Rauterberg, G.W.M.; Yang, H.S.; et al., xx

2010-01-01

This paper presents a method for monitoring mental state of small isolated crews during long-term missions (such as space mission, polar expeditions, submarine crews, meteorological stations, and etc). It combines the records of negotiation game with monitoring of the nonverbal behavior of the

Biomonitoring of physiological status and cognitive performance of underway submariners undergoing a novel watch-standing schedule

Science.gov (United States)

Duplessis, C. A.; Cullum, M. E.; Crepeau, L. J.

2005-05-01

Submarine watch-standers adhere to a 6 hour-on, 12 hour-off (6/12) watch-standing schedule, yoking them to an 18-hr day, engendering circadian desynchronization and chronic sleep deprivation. Moreover, the chronic social crowding, shift work, and confinement of submarine life provide additional stressors known to correlate with elevated secretory immunoglobulin A (sIgA) and cortisol levels, reduced performance, immunologic dysfunction, malignancies, infections, gastrointestinal illness, coronary disease, anxiety, and depression. We evaluated an alternative, compressed, fixed work schedule designed to enhance circadian rhythm entrainment, sleep hygiene, performance, and health on 10 underway submariners, who followed the alternative and 6/12 schedules for approximately 2 weeks each. We measured subjects" sleep, cognitive performance, and salivary biomarker levels. Pilot analysis of the salivary data on one subject utilizing ELISA suggests elevated biomarker levels of stress. Average PM cortisol levels were 0.2 μg/L (normal range: nondetectable - 0.15 μg/L), and mean sIgA levels were 562 μg/ml (normal range: 100-500 μg/ml). Future research exploiting real-time salivary bioassays, via fluorescent polarimetry technology, identified by the Office of Naval Research (ONR) as a future Naval requirement, allows researchers to address correlations between stress-induced elaboration of salivary biomarkers with physiological and performance decrements, thereby fostering insight into the underway submariner"s psychoimmunological status. This may help identify strategies that enhance resilience to stressors. Specifically, empirically-based modeling can identify optimal watch-standing schedules and stress-mitigating procedures -- within the operational constraints of the submarine milieu and the mission --that foster improved circadian entrainment and reduced stress reactivity, enhancing physiological health, operational performance, safety, and job satisfaction.

Design of a small nuclear reactor for extending the operational envelope of the Victoria Class Submarine

International Nuclear Information System (INIS)

Cole, C.J.P.

2003-01-01

The purpose of this research is to conceptually design a small, inherently safe, quasi-homogeneous nuclear reactor that will provide enough power to maintain the hotel load of the Victoria Class Submarine and extend her operational envelope. This research is in its early stages. The purpose of this paper is to outline the background of the research, present results found to date, and indicate the direction of the research over the next two years. The Canadian Forces has recently acquired four U.K. built Upholder Class submarines to replace the ageing Oberon Class submarines purchased in the early 1960's. The Upholders, like the Oberons, are diesel-electric powered. The Upholders were renamed the Victoria Class upon commissioning in Canada. Submarines are strategic military weapons that have several roles including: intelligence gathering, inflicting surprise attacks, controlling shipping lanes and covert operations. For each of these roles the submarine must remain undetected. To remain undetected, it is imperative that the submarine remains submerged. To remain submerged and continue to function, a submarine requires an air-independent power generation system, such as a nuclear reactor. (author)

A decision model for planetary missions

Science.gov (United States)

Hazelrigg, G. A., Jr.; Brigadier, W. L.

1976-01-01

Many techniques developed for the solution of problems in economics and operations research are directly applicable to problems involving engineering trade-offs. This paper investigates the use of utility theory for decision making in planetary exploration space missions. A decision model is derived that accounts for the objectives of the mission - science - the cost of flying the mission and the risk of mission failure. A simulation methodology for obtaining the probability distribution of science value and costs as a function spacecraft and mission design is presented and an example application of the decision methodology is given for various potential alternatives in a comet Encke mission.

Stresses in a submarine topography under ocean waves

Energy Technology Data Exchange (ETDEWEB)

Mei, C.C.; McTigue, D.F.

1984-09-01

The problem of submarine slope stability is of interest to both offshore engineering and geology. In an uneven topography, the weight above a horizontal plane induces two-dimensional variation in the static stress field. The action of wave pressure, which changes with depth, further introduces excess pore pressure and dynamic stresses in the sea bottom. In the present paper, we combine a simple analytical theory for the static stress by the present authors, and the recent solution by Mei and Foda for wave-induced stresses in a plane poro-elastic sea bed to account for mild bottom slope and wave shoaling, and obtain the effective stress field in a submarine topography under sea waves. Sample results are given for a ridge and a canyon. In particular, the dynamic pore pressure and the combined static and dynamic effective stresses are presented.

Morphodynamic Model of Submarine Canyon Incision by Sandblasting

Science.gov (United States)

Zhang, L.; Parker, G.; Izumi, N.; Cartigny, M.; Li, T.; Wang, G.

2017-12-01

Submarine canyons are carved by turbidity currents under the deep sea. As opposed to subaerial canyons, the relevant processes are not easy to observe directly. Turbidity currents are bottom-hugging sediment gravity flows of that can incise or deposit on the seafloor to create submarine canyons or fans. The triggers of turbidity currents can be storms, edge waves, internal waves, canyon wall sapping, delta failure, breaching and hyperpycnal flows. The formation and evolution mechanisms of submarine canyons are similar to those of subaerial canyons, but have substantial differences. For example, sandblasting, rather than wear due to colliding gravel clasts is more likely to be the mechanism of bedrock incision. Submarine canyons incise downward, and often develop meander bends and levees within the canyon, so defining "fairways". Here we propose a simple model for canyon incision. The starting point of our model is the Macro Roughness Saltation Abrasion Alluviation model of Zhang et al. [2015], designed for bedrock incision by gravel clasts in mixed bedrock-alluvial rivers. We adapt this formulation to consider sandblasting as a means of wear. We use a layer-averaged model for turbidity current dynamics. The current contains a mixture of mud, which helps drive the flow but which does not cause incision, and sand, which is the agent of incision. We show that the model can successfully model channel downcutting, and indeed illustrate the early formation of net incisional cyclic steps, i.e. upstream-migrating undulations on the bed associated with transcritical (in the Froude sense) flow. These steps can be expected to abet the process of incision.

Sustaining U.S. Nuclear Submarine Design Capabilities

Science.gov (United States)

2007-01-01

million annually in the NSWC’s Card- erock Division submarine design workforce in excess of reimburs - able demand to sustain skills that might...large testing infrastructure. Conse- quently, the Navy retains management and operation of these facili- ties under direct reimbursement from private...the water. 4 These facilities are maintained within the naval warfare centers, which, as working capi- tal organizations, require reimbursement from

Automatic mental heath assistant : monitoring and measuring nonverbal behavior of the crew during long-term missions

NARCIS (Netherlands)

Voynarovskaya, N.; Gorbunov, R.D.; Barakova, E.I.; Rauterberg, G.W.M.; Barakova, E.I.; Ruyter, B.; Spink, A.

2010-01-01

This paper presents a method for monitoring the mental state of small isolated crews during long-term missions (such as space mission, polar expeditions, submarine crews, meteorological stations, and etc.) The research is done as a part of Automatic Mental Health Assistant (AMHA) project which aims

Arctic Submarine Slope Stability

Science.gov (United States)

Winkelmann, D.; Geissler, W.

2010-12-01

Submarine landsliding represents aside submarine earthquakes major natural hazard to coastal and sea-floor infrastructure as well as to coastal communities due to their ability to generate large-scale tsunamis with their socio-economic consequences. The investigation of submarine landslides, their conditions and trigger mechanisms, recurrence rates and potential impact remains an important task for the evaluation of risks in coastal management and offshore industrial activities. In the light of a changing globe with warming oceans and rising sea-level accompanied by increasing human population along coasts and enhanced near- and offshore activities, slope stability issues gain more importance than ever before. The Arctic exhibits the most rapid and drastic changes and is predicted to change even faster. Aside rising air temperatures, enhanced inflow of less cooled Atlantic water into the Arctic Ocean reduces sea-ice cover and warms the surroundings. Slope stability is challenged considering large areas of permafrost and hydrates. The Hinlopen/Yermak Megaslide (HYM) north of Svalbard is the first and so far only reported large-scale submarine landslide in the Arctic Ocean. The HYM exhibits the highest headwalls that have been found on siliciclastic margins. With more than 10.000 square kilometer areal extent and app. 2.400 cubic kilometer of involved sedimentary material, it is one of the largest exposed submarine slides worldwide. Geometry and age put this slide in a special position in discussing submarine slope stability on glaciated continental margins. The HYM occurred 30 ka ago, when the global sea-level dropped by app. 50 m within less than one millennium due to rapid onset of global glaciation. It probably caused a tsunami with circum-Arctic impact and wave heights exceeding 130 meters. The HYM affected the slope stability field in its neighbourhood by removal of support. Post-megaslide slope instability as expressed in creeping and smaller-scaled slides are

Stresses in a submarine topography under ocean waves

Energy Technology Data Exchange (ETDEWEB)

Mei, C.C.; McTigue, D.F.

1984-01-01

The problem of submarine slope stability is of interest to both offshore engineering and geology. In an uneven topography, the weight above a horizontal plane induces two-dimensional variation in the static stress field. The action of wave pressure, which changes with depth, further introduces excess pore pressure and dynamic stresses in the sea bottom. In the present paper, we combine a simple analytical theory for the static stress by the present authors, and the recent solution by Mei and Foda for wave-induced stresses in a plane poro-elastic sea bed to account for mild bottom slope and wave shoaling, to obtain the effective stress field in a submarine topography under sea waves. Sample results are given for a ridge and a canyon. In particular the dynamic pore pressure and the combined static and dynamic effective stresses are presented. 10 references, 11 figures.

Direct Problems and Inverse Problems in Biometric Systems

OpenAIRE

Mihailescu Marius Iulian

2013-01-01

The article purpose is to describe the two sides of biometrics technologies, direct problems and inverse problems. The advance that we face today in field of Information Technology makes Information Security an inseparable part. The authentication has a huge role when we deal about security. The problems that can appear in implementing and developing biometrics systems is raising many problems, and one of the goal of this article is to focus on direct and inverse problems which is a new and c...

Environmental isotopic and hydrochemical study of the coastal submarine springs in Lebanon and Syria

International Nuclear Information System (INIS)

Al-Charideh, A. R.

2007-08-01

The groundwater of major karst system and the submarine springs in the Syrian coastal limestone aquifer have been studied using chemical and isotopic techniques. Stable isotopes show that the groundwater and submarine springs originates from the direct infiltration of atmospheric water. The elevation of recharge zones feeding the Banyas area (400-600 m a.s.l). The δ 18 O e xtracted for the major submarine spring at Bassieh suggests a mean recharge area elevation of 600-700 m a.s.l. Based on the measured velocity and percentage of fresh water at the submarine springs outlet (Bassieh and Tartous), the estimated discharge rate is 350 million m 3 /y. Adopting a model with exponential time distribution, the mean turnover time of groundwater in the Al-sen spring was evaluated to be 60 years. A value of about 3.7 billion m 3 was obtained for the maximum groundwater reservoir size.(Author)

“Hello, HELLO! Anyone there? - on the need to assess the tsunami risk to global submarine telecommunications infrastructure

Science.gov (United States)

Dominey-Howes, D.; Goff, J. R.

2009-12-01

National economies are increasingly dependent on the global telecommunications system - and in particular, its submarine cable infrastructure. Submarine cable traffic represents about 30% of global GDP so the cost of losing, or even simply slowing, communications traffic is high. Many natural hazards are capable of damaging and destroying this infrastructure but tsunamis are the most significant threat, particularly in waters >1000 m deep. Submarine cables and their shore-based infrastructure (the anchor points), are at risk from direct and indirect tsunami-related effects. During the 2004 Indian Ocean Tsunami in India and Indonesia, cables were broken (direct effect) as the tsunami eroded supporting sediments, and were further damaged by floating/submerged objects and intense nearshore currents. Shore-based infrastructure was also directly damaged in India, Indonesia, and the Maldives. The 1929 Grand Banks earthquake generated a submarine landslide and tsunami off Newfoundland which broke 12 submarine telegraph cables. In 2006, an earthquake in Taiwan generated submarine landslides and a tsunami. These landslides caused one of the largest disruptions of modern telecommunications history when nine cables in the Strait of Luzon were broken disabling vital connections between SE Asia and the rest of the world. Although electronic traffic in and out of Australia was slowed, it did not cease because >70% of our traffic is routed via cables that pass through Hawaii. This is extremely significant because Hawaii is an internationally recognised bottleneck or “choke point” in the global telecommunications network. The fact that Hawaii is a choke point is important because it is regularly affected by numerous large magnitude natural hazards. Any damage to the submarine telecommunications infrastructure routed through Hawaii could result in significant impacts on the electronic flow of data and voice traffic, negatively affecting dependent economies such as Australia

Geomorphic process fingerprints in submarine canyons

Science.gov (United States)

Brothers, Daniel S.; ten Brink, Uri S.; Andrews, Brian D.; Chaytor, Jason D.; Twichell, David C.

2013-01-01

Submarine canyons are common features of continental margins worldwide. They are conduits that funnel vast quantities of sediment from the continents to the deep sea. Though it is known that submarine canyons form primarily from erosion induced by submarine sediment flows, we currently lack quantitative, empirically based expressions that describe the morphology of submarine canyon networks. Multibeam bathymetry data along the entire passive US Atlantic margin (USAM) and along the active central California margin near Monterey Bay provide an opportunity to examine the fine-scale morphology of 171 slope-sourced canyons. Log–log regression analyses of canyon thalweg gradient (S) versus up-canyon catchment area (A) are used to examine linkages between morphological domains and the generation and evolution of submarine sediment flows. For example, canyon reaches of the upper continental slope are characterized by steep, linear and/or convex longitudinal profiles, whereas reaches farther down canyon have distinctly concave longitudinal profiles. The transition between these geomorphic domains is inferred to represent the downslope transformation of debris flows into erosive, canyon-flushing turbidity flows. Over geologic timescales this process appears to leave behind a predictable geomorphic fingerprint that is dependent on the catchment area of the canyon head. Catchment area, in turn, may be a proxy for the volume of sediment released during geomorphically significant failures along the upper continental slope. Focused studies of slope-sourced submarine canyons may provide new insights into the relationships between fine-scale canyon morphology and down-canyon changes in sediment flow dynamics.

Anaerobic methanotrophic communities thrive in deep submarine permafrost.

Science.gov (United States)

Winkel, Matthias; Mitzscherling, Julia; Overduin, Pier P; Horn, Fabian; Winterfeld, Maria; Rijkers, Ruud; Grigoriev, Mikhail N; Knoblauch, Christian; Mangelsdorf, Kai; Wagner, Dirk; Liebner, Susanne

2018-01-22

Thawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in submarine permafrost sediments has been proposed, but the responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic assemblages of marine and terrestrial origin (ANME-2a/b, ANME-2d) both in frozen and completely thawed submarine permafrost sediments. Besides archaea potentially involved in anaerobic oxidation of methane (AOM) we found a large diversity of archaea mainly belonging to Bathyarchaeota, Thaumarchaeota, and Euryarchaeota. Methane concentrations and δ 13 C-methane signatures distinguish horizons of potential AOM coupled either to sulfate reduction in a sulfate-methane transition zone (SMTZ) or to the reduction of other electron acceptors, such as iron, manganese or nitrate. Analysis of functional marker genes (mcrA) and fluorescence in situ hybridization (FISH) corroborate potential activity of AOM communities in submarine permafrost sediments at low temperatures. Modeled potential AOM consumes 72-100% of submarine permafrost methane and up to 1.2 Tg of carbon per year for the total expected area of submarine permafrost. This is comparable with AOM habitats such as cold seeps. We thus propose that AOM is active where submarine permafrost thaws, which should be included in global methane budgets.

Go big or die out: Bifurcation and bimodality in submarine sediment flow behaviour

Science.gov (United States)

Talling, P.; Paull, C. K.; Lintern, G.; Gwiazda, R.; Cartigny, M.; Hughes Clarke, J. E.; Xu, J.; Clare, M. A.; Parsons, D. R.; Simmons, S.; Maier, K. L.; Gales, J. A.; Hage, S.; McGann, M.; Pope, E.; Rosenberger, K. J.; Stacey, C.; Barry, J.; Lundsten, E. M.; Anderson, K.; O'Reilly, T. C.; Chapplow, N.; Vendettuoli, D.

2017-12-01

Submarine flows of sediment (turbidity currents) flush globally significant volumes of sediment and organic carbon into deep-sea basins. These flows create the largest sediment accumulations on Earth, which hold valuable oil and gas reserves. These flows affect global carbon burial, how deep-sea ecosystems function, and pose a hazard to offshore infrastructure. Only river systems transport such large amounts of sediment across such long distances. However, there are remarkably few direct measurements from active submarine flows, which is a stark contrast to >1 million direct observations from rivers. Here we present unusually detailed information on frequency, power and runout distance of multiple submarine flows at two contrasting locations. The first data set comes from Monterey Canyon, offshore California, which is fed by littoral cells. The second site is a river-fed delta in Bute Inlet, British Columbia. In both cases, the timing and runout distance of submarine flows was documented using instruments on multiple moorings placed along the 50-km long flow pathway. A striking observation is that flow behaviour and runout is strongly bimodal in both locations. Flows tend to either dissipate rapidly, or runout through the entire mooring arrays. We thus test whether i) the character of short or long runout flows can be distinguished at the first mooring and ii) whether long and short runout flows have different triggers. It has been proposed that submarine flows have two modes of behaviour; either eroding and accelerating, or depositing and dissipating. These field data support such a view of bifurcation and bimodality in flow behaviour. However, some short runout flows resemble their longer runout cousins at the first mooring, and there is no clear relationship between flow trigger and runout. Thus, some flows reach a point where their character is no longer dependent on their initial trigger or initial structure, but on factors acting along the flow pathway.

Monitoring of radioactivity at the Russian nuclear submarine Kursk

International Nuclear Information System (INIS)

Amundsen, I.; Lind, B.

2002-01-01

In the morning of August 12th 2000, a Russian submarine accident occurred in international waters east of Rybatschi Peninsula in the Barents Sea about 250 km from Norway. The submarine, a Russian Oscar class II attack submarine, sunk to 116 meters depth at the position 69 deg. 36,99N, 37 deg. 34,50E. The submarine 'Kursk' is 154 meters long, equipped with two pressurised water reactors and the submerged displacement is 24000 tons. Each reactor has a thermal effect or 190 megawatt, or less than 10% of a typical nuclear power plant reactor. The submarines in Oscar-II class is one of the largest and most capable in the Russian Northern Fleet. No indications of leakage from the submarine have so far been observed during the monitoring expeditions. Elevated levels of radioactivity have note been detected in any dose-rate readings or at any of the measurements of environmental samples taken close to Kursk. Furthermore, no increased levels were measured on bits and pieces from the submarine or from water sampled inside the submarine. A more comprehensive report covering experience and monitoring results from the two expeditions term and impact assessments of possible future releases from Kursk. (LN)

Vapour dynamics during magma-water interaction experiments: hydromagmatic origins of submarine volcaniclastic particles (limu o Pele)

Science.gov (United States)

Schipper, C. Ian; Sonder, Ingo; Schmid, Andrea; White, James D. L.; Dürig, Tobias; Zimanowski, Bernd; Büttner, Ralf

2013-03-01

Recent observations have shattered the long-held theory that deep-sea (>500 m) explosive eruptions are impossible; however, determining the dynamics of unobserved eruptions requires interpretation of the deposits they produce. For accurate interpretation to be possible, the relative abilities of explosive magmatic degassing and non-explosive magma-water interaction to produce characteristic submarine volcaniclastic particles such as `limu o Pele' (bubble wall shards of glass) must be established. We experimentally address this problem by pouring remelted basalt (1300 °C, anhydrous) into a transparent, water-filled reservoir, recording the interaction with a high-speed video camera and applying existing heat transfer models. We performed the experiments under moderate to high degrees of water subcooling (˜8 l of water at 58 and 3 °C), with ˜0.1 to 0.15 kg of melt poured at ˜10-2 kg s-1. Videos show the non-explosive, hydromagmatic blowing and bursting of isolated melt bubbles to form limu o Pele particles that are indistinguishable from those found in submarine volcaniclastic deposits. Pool boiling around growing melt bubbles progresses from metastable vapour film insulation, through vapour film retraction/collapse, to direct melt-water contact. These stages are linked to the evolution of melt-water heat transfer to verify the inverse relationship between vapour film stability and the degree of water subcooling. The direct contact stage in particular explains the extremely rapid quench rates determined from glass relaxation speedometry for natural limu. Since our experimentally produced limu is made entirely by the entrapping of ambient water in degassed basaltic melt, we argue that the presence of fast-quenched limu o Pele in natural deposits is not diagnostic of volatile-driven explosive eruptions. This must be taken into account if submarine eruption dynamics are to be accurately inferred from the deposits and particles they produce.

What threat do turbidity currents and submarine landslides pose to submarine telecommunications cable infrastructure?

Science.gov (United States)

Clare, Michael; Pope, Edward; Talling, Peter; Hunt, James; Carter, Lionel

2016-04-01

The global economy relies on uninterrupted usage of a network of telecommunication cables on the seafloor. These submarine cables carry ~99% of all trans-oceanic digital data and voice communications traffic worldwide, as they have far greater bandwidth than satellites. Over 9 million SWIFT banks transfers alone were made using these cables in 2004, totalling 7.4 trillion of transactions per day between 208 countries, which grew to 15 million SWIFT bank transactions last year. We outline the challenge of why, how often, and where seafloor cables are broken by natural causes; primarily subsea landslides and sediment flows (turbidity currents and also debris flows and hyperpycnal flows). These slides and flows can be very destructive. As an example, a sediment flow in 1929 travelled up to 19 m/s and broke 11 cables in the NE Atlantic, running out for ~800 km to the abyssal ocean. The 2006 Pingtung earthquake triggered a sediment flow that broke 22 cables offshore Taiwan over a distance of 450 km. Here, we present initial results from the first statistical analysis of a global database of cable breaks and causes. We first investigate the controls on frequency of submarine cable breaks in different environmental and geological settings worldwide. We assess which types of earthquake pose a significant threat to submarine cable networks. Meteorological events, such as hurricanes and typhoons, pose a significant threat to submarine cable networks, so we also discuss the potential impacts of future climate change on the frequency of such hazards. We then go on to ask what are the physical impacts of submarine sediment flows on submerged cables? A striking observation from past cable breaks is sometimes cables remain unbroken, whilst adjacent cables are severed (and record powerful flows travelling at up to 6 m/s). Why are some cables broken, but neighbouring cables remain intact? We provide some explanations for this question, and outline the need for future in

Influence of Anchoring on Burial Depth of Submarine Pipelines.

Science.gov (United States)

Zhuang, Yuan; Li, Yang; Su, Wei

2016-01-01

Since the beginning of the twenty-first century, there has been widespread construction of submarine oil-gas transmission pipelines due to an increase in offshore oil exploration. Vessel anchoring operations are causing more damage to submarine pipelines due to shipping transportation also increasing. Therefore, it is essential that the influence of anchoring on the required burial depth of submarine pipelines is determined. In this paper, mathematical models for ordinary anchoring and emergency anchoring have been established to derive an anchor impact energy equation for each condition. The required effective burial depth for submarine pipelines has then been calculated via an energy absorption equation for the protection layer covering the submarine pipelines. Finally, the results of the model calculation have been verified by accident case analysis, and the impact of the anchoring height, anchoring water depth and the anchor weight on the required burial depth of submarine pipelines has been further analyzed.

Estimating the empirical probability of submarine landslide occurrence

Science.gov (United States)

Geist, Eric L.; Parsons, Thomas E.; Mosher, David C.; Shipp, Craig; Moscardelli, Lorena; Chaytor, Jason D.; Baxter, Christopher D. P.; Lee, Homa J.; Urgeles, Roger

2010-01-01

The empirical probability for the occurrence of submarine landslides at a given location can be estimated from age dates of past landslides. In this study, tools developed to estimate earthquake probability from paleoseismic horizons are adapted to estimate submarine landslide probability. In both types of estimates, one has to account for the uncertainty associated with age-dating individual events as well as the open time intervals before and after the observed sequence of landslides. For observed sequences of submarine landslides, we typically only have the age date of the youngest event and possibly of a seismic horizon that lies below the oldest event in a landslide sequence. We use an empirical Bayes analysis based on the Poisson-Gamma conjugate prior model specifically applied to the landslide probability problem. This model assumes that landslide events as imaged in geophysical data are independent and occur in time according to a Poisson distribution characterized by a rate parameter λ. With this method, we are able to estimate the most likely value of λ and, importantly, the range of uncertainty in this estimate. Examples considered include landslide sequences observed in the Santa Barbara Channel, California, and in Port Valdez, Alaska. We confirm that given the uncertainties of age dating that landslide complexes can be treated as single events by performing statistical test of age dates representing the main failure episode of the Holocene Storegga landslide complex.

Influence of Anchoring on Burial Depth of Submarine Pipelines.

Directory of Open Access Journals (Sweden)

Yuan Zhuang

Full Text Available Since the beginning of the twenty-first century, there has been widespread construction of submarine oil-gas transmission pipelines due to an increase in offshore oil exploration. Vessel anchoring operations are causing more damage to submarine pipelines due to shipping transportation also increasing. Therefore, it is essential that the influence of anchoring on the required burial depth of submarine pipelines is determined. In this paper, mathematical models for ordinary anchoring and emergency anchoring have been established to derive an anchor impact energy equation for each condition. The required effective burial depth for submarine pipelines has then been calculated via an energy absorption equation for the protection layer covering the submarine pipelines. Finally, the results of the model calculation have been verified by accident case analysis, and the impact of the anchoring height, anchoring water depth and the anchor weight on the required burial depth of submarine pipelines has been further analyzed.

Enhancing Submarine Operational Relevance: A Leadership Challenge

National Research Council Canada - National Science Library

Daigle, Jr, Michael J

2008-01-01

.... This vision of submarine operations must change. As the military continues to shift to operations focused on joint capabilities, the submarine force must break from the closed, protective, and risk averse culture of its past and push forward...

Exoplanet Classification and Yield Estimates for Direct Imaging Missions

Science.gov (United States)

Kopparapu, Ravi Kumar; Hébrard, Eric; Belikov, Rus; Batalha, Natalie M.; Mulders, Gijs D.; Stark, Chris; Teal, Dillon; Domagal-Goldman, Shawn; Mandell, Avi

2018-04-01

Future NASA concept missions that are currently under study, like the Habitable Exoplanet Imaging Mission (HabEx) and the Large Ultra-violet Optical Infra Red Surveyor, could discover a large diversity of exoplanets. We propose here a classification scheme that distinguishes exoplanets into different categories based on their size and incident stellar flux, for the purpose of providing the expected number of exoplanets observed (yield) with direct imaging missions. The boundaries of this classification can be computed using the known chemical behavior of gases and condensates at different pressures and temperatures in a planetary atmosphere. In this study, we initially focus on condensation curves for sphalerite ZnS, {{{H}}}2{{O}}, {CO}}2, and {CH}}4. The order in which these species condense in a planetary atmosphere define the boundaries between different classes of planets. Broadly, the planets are divided into rocky planets (0.5–1.0 R ⊕), super-Earths (1.0–1.75 R ⊕), sub-Neptunes (1.75–3.5 R ⊕), sub-Jovians (3.5–6.0 R ⊕), and Jovians (6–14.3 R ⊕) based on their planet sizes, and “hot,” “warm,” and “cold” based on the incident stellar flux. We then calculate planet occurrence rates within these boundaries for different kinds of exoplanets, η planet, using the community coordinated results of NASA’s Exoplanet Program Analysis Group’s Science Analysis Group-13 (SAG-13). These occurrence rate estimates are in turn used to estimate the expected exoplanet yields for direct imaging missions of different telescope diameters.

Colors of Alien Worlds from Direct Imaging Exoplanet Missions

Science.gov (United States)

Hu, Renyu

2016-01-01

Future direct-imaging exoplanet missions such as WFIRST will measure the reflectivity of exoplanets at visible wavelengths. Most of the exoplanets to be observed will be located further away from their parent stars than is Earth from the Sun. These "cold" exoplanets have atmospheric environments conducive for the formation of water and/or ammonia clouds, like Jupiter in the Solar System. I find the mixing ratio of methane and the pressure level of the uppermost cloud deck on these planets can be uniquely determined from their reflection spectra, with moderate spectral resolution, if the cloud deck is between 0.6 and 1.5 bars. The existence of this unique solution is useful for exoplanet direct imaging missions for several reasons. First, the weak bands and strong bands of methane enable the measurement of the methane mixing ratio and the cloud pressure, although an overlying haze layer can bias the estimate of the latter. Second, the cloud pressure, once derived, yields an important constraint on the internal heat flux from the planet, and thus indicating its thermal evolution. Third, water worlds having H2O-dominated atmospheres are likely to have water clouds located higher than the 10-3 bar pressure level, and muted spectral absorption features. These planets would occupy a confined phase space in the color-color diagrams, likely distinguishable from H2-rich giant exoplanets by broadband observations. Therefore, direct-imaging exoplanet missions may offer the capability to broadly distinguish H2-rich giant exoplanets versus H2O-rich super-Earth exoplanets, and to detect ammonia and/or water clouds and methane gas in their atmospheres.

Monitoring of the nuclear submarine Komsomolets

Energy Technology Data Exchange (ETDEWEB)

Heldal, Hilde E.; Flo, Janita K.; Liebig, Penny L. [Institute of Marine Research, P. O. Box 1870 Nordnes, N-5817 Bergen (Norway); Gaefvert, Torbjoern; Rudjord, Anne Liv [Norwegian Radiation Protection Authority, P.O. Box 55, N-1332 Oesteraas (Norway); Gwynn, Justin P. [Norwegian Radiation Protection Authority, The Fram Centre, N-9296 Tromsoe (Norway)

2014-07-01

The Soviet nuclear submarine Komsomolets sank on the 7 April 1989, 180 km southwest of Bear Island in the Norwegian Sea to a depth of about 1655 m. The submarine contains one nuclear reactor containing long-lived radionuclides such as cesium-137 ({sup 137}Cs) along with other fission and activation products, in addition to 2 mixed uranium/plutonium nuclear warheads containing weapons grade plutonium. Although several model studies have shown that a radioactive leakage from Komsomolets will have insignificant impact on fish and other marine organisms, there are still public concerns about the condition of the submarine and the potential for radioactive leakage. In order to document the contamination levels and to meet public concerns, monitoring of radioactive contamination in the area adjacent to the submarine has been ongoing since 1993. Samples of bottom seawater and sediments have been collected annually by the Institute of Marine Research (IMR) and have been analysed for {sup 137}Cs and plutonium-239,240 ({sup 239,240}Pu). So far, activity concentrations in the samples have been comparable to levels found in other samples from the Norwegian and Barents Seas. During sampling from R/V 'G. O. Sars' in April 2013, an area of about 1 km{sup 2} of the seabed around Komsomolets was mapped to precisely locate the submarine using a Kongsberg EM302 multibeam echo sounder, a Simrad EK60 single beam echo sounder and an Olex 3D bottom-mapping system. For sediment sampling, a Simrad MST342 mini-transponder was attached to a Smoegen box corer to allow for precise positioning of the corer. With the aid of the Kongsberg HiPAP (High Precision Acoustic Positioning) system, 4 box cores were collected around the submarine at a distance of 10 to 20 m. In addition, one box core was collected from a reference station about 100 m upstream of the submarine. Surface sediments and sediment cores were collected from the box cores taken at each sampling location. Sediment cores

Submarine fans: A critical retrospective (1950–2015

Directory of Open Access Journals (Sweden)

G. Shanmugam

2016-04-01

Full Text Available When we look back the contributions on submarine fans during the past 65 years (1950–2015, the empirical data on 21 modern submarine fans and 10 ancient deep-water systems, published by the results of the First COMFAN (Committee on FANs Meeting (Bouma et al., 1985a, have remained the single most significant compilation of data on submarine fans. The 1970s were the “heyday” of submarine fan models. In the 21st century, the general focus has shifted from submarine fans to submarine mass movements, internal waves and tides, and contourites. The purpose of this review is to illustrate the complexity of issues surrounding the origin and classification of submarine fans. The principal elements of submarine fans, composed of canyons, channels, and lobes, are discussed using nine modern case studies from the Mediterranean Sea, the Equatorial Atlantic, the Gulf of Mexico, the North Pacific, the NE Indian Ocean (Bay of Bengal, and the East Sea (Korea. The Annot Sandstone (Eocene–Oligocene, exposed at Peira-Cava area, SE France, which served as the type locality for the “Bouma Sequence”, was reexamined. The field details are documented in questioning the validity of the model, which was the basis for the turbidite-fan link. The 29 fan-related models that are of conceptual significance, developed during the period 1970–2015, are discussed using modern and ancient systems. They are: (1 the classic submarine fan model with attached lobes, (2 the detached-lobe model, (3 the channel-levee complex without lobes, (4 the delta-fed ramp model, (5 the gully-lobe model, (6 the suprafan lobe model, (7 the depositional lobe model, (8 the fan lobe model, (9 the ponded lobe model, (10 the nine models based on grain size and sediment source, (11 the four fan models based on tectonic settings, (12 the Jackfork debrite model, (13 the basin-floor fan model, (14 supercritical and subcritical fans, and (15 the three types of fan reservoirs. Each model is unique

Improved Submariner Eyewear for Routine Wear and Emergency Equipment Use Underway

Science.gov (United States)

2010-01-15

information. 2.0 DESCRIPTION Naval Submarine Medical Research Laboratory (NSMRL) is seeking information from the eyewear industry that will provide...Improved Submariner Eyewear for Routine Wear and Emergency Equipment Use Underway by Alison America, MA Wayne G. Horn, MD...Submariner Eyewear for Routine Wear and Emergency Equipment Use Underway 50818 Alison America, MA Wayne G. Horn, MD Naval Submarine Medical Research

VICTORIA Class Submarine Human-in-the-Loop Experimentation Plan

Science.gov (United States)

2014-06-01

1472G. VICTORIA Class Submarine Human-in-the-Loop Experimentation Plan and Preliminary Results © Her Majesty the Queen in Right of...19 th International Command and Control Research and Technology Symposium Title: VICTORIA Class Submarine Human-in-the-Loop...TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE VICTORIA Class Submarine Human-in-the-Loop Experimentation Plan 5a. CONTRACT

Index of Submarine Medical Officer’s Qualification Theses 1944-1974

Science.gov (United States)

1976-04-01

USING HYPOTHERMIA AND HYPERBARIC CXYGENATI 1972-3011 0 A CASE REPO+ HYPOBARIC HYPOXIA ABOARD A SUBMERGED SUBMARINE 1972-0014 THE EFFECTS OF ACUTE HYPOXIA...G009 LEVEL. VENTILATORY DYNAMICS UNDER HYPERBARIC STATES.= SUBMARINE MEDICAL QUALIFICATION THESES U. So NAVAL SJBMARINE MEDICAL CENTER SUBMARINE BASE...CONNECTICUT. 23 OCT 62 StJRL ____________ 1962-0019 WOO3D W.- - ____ VENTILATORY DYNAMICS UNDER HYPERBARIC STATES.= SUBMARINE MEDICAL QUALIFICATION THESES

33 CFR 165.1302 - Bangor Naval Submarine Base, Bangor, WA.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Bangor Naval Submarine Base... Bangor Naval Submarine Base, Bangor, WA. (a) Location. The following is a security zone: The waters of... States Naval vessels. (ii) Vessels that are performing work at Naval Submarine Base Bangor pursuant to a...

Risks and consequences of a hypothetical radiological accident on nuclear powered submarine traversing Suez canal

International Nuclear Information System (INIS)

Salama, Mohamed

2008-01-01

Full text: Egypt has unique problem in Suez Canal, although there are, a number of radioactive Cargos traveling through the Canal which includes new and spent reactor fuel and about 100 metric tons of uranium hexafluoride each year, under the regulatory control of the Egyptian Atomic Energy Authority, there is, still a major problem concerning the passage of a number of nuclear powered vessels and submarines passing through the canal several times each year. The passage of these vessels and submarines has a political situation and not under the regulatory control of the Egyptian regulatory body. In spite of all precautions that are taken, in the nuclear powered vessels and submarines from the point of view of the rugged design of the reactor plant, multiple safety systems and operation with exceptional consideration for safety. Although of all of these a potential for a serious accident may does arise, even though, its probability is minimal. The Government of Egypt has established a national radiological emergency plan in order to cope with any radiological accidents, which may arise inside the country. Suez Canal lies in the north east of Egypt, and passes through a zone of considerable business, agriculture and industrial activities. The zone consists of three populated provinces, Port Said, Ismailia and Suez. According to Suez Canal authority regulations it is not allowed for these vessels and submarines to be landed in port. The motivation of the present paper was undertaken to discuss a hypothetical nuclear reactor accident aboard a nuclear powered submarine occurred during its passage in the Suez Canal. Such an accident will produce a radioactive cloud containing a number of radioactive materials. In such type of accidents contamination and causality zones, could extend to several kilometers. The different phases of the accident are going to be discussed and analyzed. The emergency actions taken during the accident phases are going to be presented. The

Can sea level rise cause large submarine landslides on continental slopes?

Science.gov (United States)

Urlaub, Morelia

2014-05-01

Submarine landslides are one of the volumetrically most important sediment transport processes at continental margins. Moreover, these landslides are a major geohazard as they can cause damaging tsunamis and destroy seabed infrastructure. Due to their inaccessibility our understanding of what causes these landslides is limited and based on hypotheses that are difficult to test. Some of the largest submarine landslides, such as the Storegga Slide off Norway, occurred during times of eustatic sea level rise. It has been suggested that this global sea level rise was implicated in triggering of the landslides by causing an increase in excess pore pressure in the subseafloor. However, in a homogeneous slope a change in the thickness of the overlying water mass is not expected to affect its stability, as only the hydrostatic pressure component will change, whereas pore pressures in excess of hydrostatic will remain unaltered. Whether sufficiently rapid sea level rise, aided by rather impermeable sediment and complex layering, could cause excess pore pressures that may destabilise a continental slope is more difficult to answer and has not yet been tested. I use Finite Element Modelling to explore and quantify the direct effect of changes in the thickness of the overlying water mass on the stability of a generic sediment column with different stratigraphic conditions and hydro-mechanical properties. The results show that the direct effect of sea level rise on continental slope stability is minimal. Nevertheless, sea level rise may foster other processes, such as lithospheric stress changes resulting in increased seismicity, that could potentially cause large submarine landslides on continental slopes.

Anaesthesia in austere environments: literature review and considerations for future space exploration missions.

Science.gov (United States)

Komorowski, Matthieu; Fleming, Sarah; Mawkin, Mala; Hinkelbein, Jochen

2018-01-01

Future space exploration missions will take humans far beyond low Earth orbit and require complete crew autonomy. The ability to provide anaesthesia will be important given the expected risk of severe medical events requiring surgery. Knowledge and experience of such procedures during space missions is currently extremely limited. Austere and isolated environments (such as polar bases or submarines) have been used extensively as test beds for spaceflight to probe hazards, train crews, develop clinical protocols and countermeasures for prospective space missions. We have conducted a literature review on anaesthesia in austere environments relevant to distant space missions. In each setting, we assessed how the problems related to the provision of anaesthesia (e.g., medical kit and skills) are dealt with or prepared for. We analysed how these factors could be applied to the unique environment of a space exploration mission. The delivery of anaesthesia will be complicated by many factors including space-induced physiological changes and limitations in skills and equipment. The basic principles of a safe anaesthesia in an austere environment (appropriate training, presence of minimal safety and monitoring equipment, etc.) can be extended to the context of a space exploration mission. Skills redundancy is an important safety factor, and basic competency in anaesthesia should be part of the skillset of several crewmembers. The literature suggests that safe and effective anaesthesia could be achieved by a physician during future space exploration missions. In a life-or-limb situation, non-physicians may be able to conduct anaesthetic procedures, including simplified general anaesthesia.

Scientific Ocean Drilling to Assess Submarine Geohazards along European Margins

Science.gov (United States)

Ask, M. V.; Camerlenghi, A.; Kopf, A.; Morgan, J. K.; Ocean DrillingSeismic Hazard, P. E.

2008-12-01

Integrated Ocean Drilling Program (IODP) provides technologically top-level drilling vessels and platforms that can be used by scientists to address global scientific problems, including the causes and processes responsible for submarine geohazards. Both IODP and ECORD (the European Consortium for Ocean Research Drilling in collaboration with the European Science Foundation) support scientific initiatives towards submarine geohazards, because the geological record of geohazards can be read and interpreted only through ocean drilling, combined with a broad array of geophysical, geotechnical, and laboratory studies, to identify structures and deposits associated with hazardous phenomena.

Submarine films as narratives of masculinity

OpenAIRE

MacDonald, Alex

2002-01-01

The research for this thesis is on representations of masculinity in Anglo-American submarine films since 1943. The discussion will draw on relevant work on the representation of masculinity and popular cinema in film and cultural studies. In particular, the thesis will account for the notion of hegemony in relation to masculinity in the submarine film. Further, the notion of hegemonic masculinity will be addressed in terms of four key claims. These are as follows: that relations between grou...

Nuclear power supplies: their potential and the practical problems to their achievement for space missions

International Nuclear Information System (INIS)

Colston, B.W.; Brehm, R.L.

1985-01-01

The anticipated growth of the space station power requirement provides a good example of the problem the space nuclear power supply developers have to contend with: should a reactor power supply be developed that attempts to be all things to all missions, i.e., is highly flexible in its ability to meet a wide variety of missions, or should the development of a reactor system await a specific mission definition and be customized to this mission. This leads, of course, to a chicken-and-egg situation. For power requirements of several hundreds of kilowatts or more, no nuclear power source exists or is even far enough along in the definition stage (much less the development stage) for NASA to reasonably assume probable availability within the next 10 years. The real problem of space nuclear power is this ''chicken-and-egg'' syndrome: DOE will not develop a space reactor system for NASA without a firm mission, and NASA will not specify a firm mission requiring a space reactor because such a system doesn't exist and is perceived not to be developable within the time frame of the mission. The problem is how to break this cycle. The SP-100 program has taken an important first step to breaking this cycle, but this program is much more design-specific than what is required to achieve a broad technology base and latitude in achievable power level. In contrast to the SP-100 approach, a wider perspective is required: the development of the appropriate technologies for power levels can be broken into ranges, say, from 100 kWe to 1000 kWe, and from 1000 kWe to 10,000 kWe

Optical image modulation above the submarine bottom topography: a case study on the Taiwan Banks, China

Science.gov (United States)

Li, Yan; Hu, Jianyu; Li, Jing; Fu, Bin; Ma, Liming

2003-05-01

A possible mechanism to explain the correlation between submarine topography and the direct sunlight specially reflected from the sea surface with variable roughness caused by the bottom-current effect was suggested fifteen years ago by Henning et al. in International Journal of Remote Sensing, 9, 45-67, after comparing radar satellite image and Skylab satellite photograph of the North American east coast (Nantucket Shoals) with submarine relief features. A case study is carried out in the famous sand waves field located at the Taiwan banks of Taiwan Strait in August 1998. The TM images, either visible bands (TM1, TM2, TM3) or near infrared bands (TM4, TM5, TM7), shows submarine relief features for sand waves, with wavelength of 300 to 2000 meters, riding on the lager scale sand ridges and channel system. Sea truth data including 660 nm beam attenuation coefficient profiles were conducted in the same period. We compare signals of TM images, attenuation coefficient profiles, and sounding maps of the Taiwan Bands. The subsurface upwelling signals with contributions of the water column and the bottom, either estimated by single or quasi-single-scattering theory or revealed by the TM images after removing the contribution of direct sunlight reflected signals from sea surface, were too weak to distinguish the ridges and troughs of bedforms especially for red and near infrared bands. However, the direct sunlight specially reflected signals from the sea surface, approximately at same level in water-leaving reflectance not only for visible bands (TM1, TM2, TM3) but also for near infrared bands (TM4, TM5, TM7), was the major submarine bottom topography signals especially for those pixels towards the direction of the sun azimuth. Following a physical description for the lee waves appeared on free surface when the current flows round an underwater obstacle, the direct sunlight reflected signals related wave face slope, is dominated by the height and depth of sand waves and

International aid is needed in resolving the military nuclear waste problems in Kola peninsula

International Nuclear Information System (INIS)

Forss, S.

1995-01-01

Information about military nuclear waste problems in the counties of Murmansk and Arkhangelsk has become public on an unprecedented scale since the end of the cold war and the collapse of the Soviet Union. Relevant technical details about the nuclear waste problem are still unclassified. The amount of knowledge is, however, steadily increasing despite military secrecy. It is now possible to perform a fairly reliable evaluation of the scope and magnitude of the nuclear waste problem that stems from more than three decades of operation of nuclear submarines and ships of the former Soviet Northern Fleet. The former Soviet Navy built some 240 nuclear submarines, most of them with twin reactors. About 180 nuclear submarines will have to be disposed of in the coming years. Since the late eighties the Soviet/Russian Navy has retired about twenty nuclear submarines a year. Approximately one hundred nuclear submarines now lie in Russian harbours in the North and in the Far East, awaiting disposal. More than seventy are in the Kola and Arkhangelsk areas. Most of the retired submarines still carry nuclear fuel in their reactor. (orig.)

'Good Hunting': German submarine offensives and South African ...

African Journals Online (AJOL)

By the latter half of 1942, the High Command of the German U-boats (BdU) realised that the 'sinking results' of the North Atlantic had decreased immensely. The successes of the Allied anti-submarine operations in the North Atlantic precluded the successful employment of the German submarines in said waters.

Direct channel problems and phenomena

International Nuclear Information System (INIS)

Cutkosky, R.E.

1975-01-01

Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

Partly standing internal tides in a dendritic submarine canyon observed by an ocean glider

Science.gov (United States)

Hall, Rob A.; Aslam, Tahmeena; Huvenne, Veerle A. I.

2017-08-01

An autonomous ocean glider is used to make the first direct measurements of internal tides within Whittard Canyon, a large, dendritic submarine canyon system that incises the Celtic Sea continental slope and a site of high benthic biodiversity. This is the first time a glider has been used for targeted observations of internal tides in a submarine canyon. Vertical isopycnal displacement observations at different stations fit a one-dimensional model of partly standing semidiurnal internal tides - comprised of a major, incident wave propagating up the canyon limbs and a minor wave reflected back down-canyon by steep, supercritical bathymetry near the canyon heads. The up-canyon internal tide energy flux in the primary study limb decreases from 9.2 to 2.0 kW m-1 over 28 km (a dissipation rate of 1 - 2.5 ×10-7 Wkg-1), comparable to elevated energy fluxes and internal tide driven mixing measured in other canyon systems. Within Whittard Canyon, enhanced mixing is inferred from collapsed temperature-salinity curves and weakened dissolved oxygen concentration gradients near the canyon heads. It has previously been hypothesised that internal tides impact benthic fauna through elevated near-bottom current velocities and particle resuspension. In support of this, we infer order 20 cm s-1 near-bottom current velocities in the canyon and observe high concentrations of suspended particulate matter. The glider observations are also used to estimate a 1 °C temperature range and 12 μmol kg-1 dissolved oxygen concentration range, experienced twice a day by organisms on the canyon walls, due to the presence of internal tides. This study highlights how a well-designed glider mission, incorporating a series of tide-resolving stations at key locations, can be used to understand internal tide dynamics in a region of complex topography, a sampling strategy that is applicable to continental shelves and slopes worldwide.

The missing link between submarine volcano and promising geothermal potential in Jinshan, Northern Taiwan

Science.gov (United States)

Wang, S. C.; Hutchings, L.; Chang, C. C.; Lee, C. S.

2017-12-01

The Tatun volcanic group (TVG) and the Keelung submarine volcano (KSV) are active volcanoes and surrounding three nuclear plant sites in north Taiwan. The famous Jinshan-Wanli hot springs locates between TVG and KSV, moreover, the geochemical anomalies of acidic boiling springs on the seacoast infer that the origin is from magmatic fluids, sea water and meteoric water mixture, strongly implying that mantle fluids ascends into the shallow crust. The evidence for a magma chamber, submarine volcano, and boiling springs have a close spatial relationship. Based on UNECE specifications to Geothermal Energy Resources (2016), the Jinshan-Wanli geothermal area could be classified as Known Geothermal Energy Source for geothermal direct use and Potential Geothermal Energy Source for conventional geothermal system. High resolution reservoir exploration and modeling in Jinshan-Wanli geothermal area is developing for drilling risk mitigation. The geothermal team of National Taiwan Ocean University and local experts are cooperating for further exploration drilling and geothermal source evaluation. Keywords: geothermal resource evaluation, Jinshan-Wanli geothermal area, submarine volcano

Worldwide overview of nuclear submarine decommissioning plans and issues

International Nuclear Information System (INIS)

Oelgaard, P.L.

1995-06-01

The number of nuclear propelled vessels that have reached the end of their useful life, is increasing. This raises the question of what to do with these vessels. In this paper the order of magnitude of the problem is first discussed, i.e. the number of nuclear ships built and the number already taken out of service. Next the problems of the first stages of decommissioning are discussed, i.e. the removal of the fuel and the preparation of the reactor parts for final disposal, including the amounts of radioactivity involved. Thirdly, the various methods of final disposal are considered, sea disposal, shallow land burial and deep land burial. Finally, the risks involved in nuclear submarine decommissioning are briefly discussed. (au)

Introduction to the special issue on submarine geohazard records and potential seafloor instability

Directory of Open Access Journals (Sweden)

Song-Chuen Chen Jia-Jyun Dong

2018-01-01

Full Text Available Submarine landslides frequently occur in passive continental margins or active margins (Hampton et al. 1996; Wynn et al. 2000; Mienert et al. 2002; Korup et al. 2007; Twichell et al. 2009; Cukur et al. 2016. Submarine landslides have been studied extensively not only for scientific research but also for submarine geohazards. Submarine landslides could jeopardize marine infrastructures, such as offshore drilling platforms or submarine telecommunication cables, and could even trigger disastrous tsunamis (Bondevik et al. 2005; Harbitz et al. 2006; Hornbach et al. 2007, 2008; Hsu et al. 2008; Su et al. 2012; Tappin et al. 2014; Li et al. 2015. For instance, one disastrous tsunami hitting the coastal area of southwestern Taiwan in 1781 or 1782 was reported (Chen 1830; Hsu 1983; the tsunami event was probably generated by submarine landslides in the offshore area of southwestern Taiwan (Li et al. 2015. Moreover, several submarine landslides triggered by the 2006 Pingtung earthquake have induced turbidity currents off southwest Taiwan and destroyed about 14 submarine telecommunication cables off SW Taiwan (Hsu et al. 2008. The area of southwest Taiwan currently has a dense population (more than 3 million people in total, one deep-water Kaohsiung Port, several tanks of liquefied natural gas and a nuclear power plant on the coast (Fig. 1. Numerous submarine telecommunication cables exist off SW Taiwan. If a considerable tsunami event would hit again the costal area of SW Taiwan, the damage could very serious. Likewise, there are two nuclear power plants on the coast of northern Taiwan (Fig. 2, and the population in northern Taiwan has more than 10 million people. Submarine telecommunication cables also exist off northern Taiwan. In any case, it is important to understand the status of seafloor stability in the offshore areas of SW and NE Taiwan. For that, this special issue of submarine geohazard records and potential seafloor instability is aimed to

Optimal Mission Abort Policy for Systems Operating in a Random Environment.

Science.gov (United States)

Levitin, Gregory; Finkelstein, Maxim

2018-04-01

Many real-world critical systems, e.g., aircrafts, manned space flight systems, and submarines, utilize mission aborts to enhance their survivability. Specifically, a mission can be aborted when a certain malfunction condition is met and a rescue or recovery procedure is then initiated. For systems exposed to external impacts, the malfunctions are often caused by the consequences of these impacts. Traditional system reliability models typically cannot address a possibility of mission aborts. Therefore, in this article, we first develop the corresponding methodology for modeling and evaluation of the mission success probability and survivability of systems experiencing both internal failures and external shocks. We consider a policy when a mission is aborted and a rescue procedure is activated upon occurrence of the mth shock. We demonstrate the tradeoff between the system survivability and the mission success probability that should be balanced by the proper choice of the decision variable m. A detailed illustrative example of a mission performed by an unmanned aerial vehicle is presented. © 2017 Society for Risk Analysis.

Durable terrestrial bedrock predicts submarine canyon formation

Science.gov (United States)

Smith, Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

2017-01-01

Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

A new submarine oil-water separation system

Science.gov (United States)

Cai, Wen-Bin; Liu, Bo-Hong

2017-12-01

In order to solve the oil field losses of environmental problems and economic benefit caused by the separation of lifting production liquid to offshore platforms in the current offshore oil production, from the most basic separation principle, a new oil-water separation system has been processed of adsorption and desorption on related materials, achieving high efficiency and separation of oil and water phases. And the submarine oil-water separation device has been designed. The main structure of the device consists of gas-solid phase separation device, period separating device and adsorption device that completed high efficiency separation of oil, gas and water under the adsorption and desorption principle, and the processing capacity of the device is calculated.

Submarine landslides on the north continental slope of the South China Sea

Science.gov (United States)

Wang, Weiwei; Wang, Dawei; Wu, Shiguo; Völker, David; Zeng, Hongliu; Cai, Guanqiang; Li, Qingping

2018-02-01

Recent and paleo-submarine landslides are widely distributed within strata in deep-water areas along continental slopes, uplifts, and carbonate platforms on the north continental margin of the South China Sea (SCS). In this paper, high-resolution 3D seismic data and multibeam data based on seismic sedimentology and geomorphology are employed to assist in identifying submarine landslides. In addition, deposition models are proposed that are based on specific geological structures and features, and which illustrate the local stress field over entire submarine landslides in deep-water areas of the SCS. The SCS is one of the largest fluvial sediment sinks in enclosed or semi-enclosed marginal seas worldwide. It therefore provides a set of preconditions for the formation of submarine landslides, including rapid sediment accumulation, formation of gas hydrates, and fluid overpressure. A new concept involving temporal and spatial analyses is tested to construct a relationship between submarine landslides and different time scale trigger mechanisms, and three mechanisms are discussed in the context of spatial scale and temporal frequency: evolution of slope gradient and overpressure, global environmental changes, and tectonic events. Submarine landslides that are triggered by tectonic events are the largest but occur less frequently, while submarine landslides triggered by the combination of slope gradient and over-pressure evolution are the smallest but most frequently occurring events. In summary, analysis shows that the formation of submarine landslides is a complex process involving the operation of different factors on various time scales.

A mission executor for an autonomous underwater vehicle

Science.gov (United States)

Lee, Yuh-Jeng; Wilkinson, Paul

1991-01-01

The Naval Postgraduate School has been conducting research into the design and testing of an Autonomous Underwater Vehicle (AUV). One facet of this research is to incrementally design a software architecture and implement it in an advanced testbed, the AUV II. As part of the high level architecture, a Mission Executor is being constructed using CLIPS (C Language Integrated Production System) version 5.0. The Mission Executor is an expert system designed to oversee progress from the AUV launch point to a goal area and back to the origin. It is expected that the executor will make informed decisions about the mission, taking into account the navigational path, the vehicle subsystem health, and the sea environment, as well as the specific mission profile which is downloaded from an offboard mission planner. Heuristics for maneuvering, avoidance of uncharted obstacles, waypoint navigation, and reaction to emergencies (essentially the expert knowledge of a submarine captain) are required. Many of the vehicle subsystems are modeled as objects using the CLIPS Object Oriented Language (COOL) embedded in CLIPS 5.0. Also, truth maintenance is applied to the knowledge base to keep configurations updated.

Environmental assessment of submarine power cables

Energy Technology Data Exchange (ETDEWEB)

Isus, Daniel; Martinez, Juan D. [Grupo General Cable Sistemas, S.A., 08560-Manlleu, Barcelona (Spain); Arteche, Amaya; Del Rio, Carmen; Madina, Virginia [Tecnalia Research and Innovation, 20009 San Sebastian (Spain)

2011-03-15

-impregnated external sheath is not enough as isolation material to avoid the chemicals of galvanized impact on the sea environment. However the HDPE jacket avoids the pollution of sea by the other inside heavy metals like iron and copper. The DOC results showed growing trends in all cases, although the growing rate in broken cable was higher than rate of undamaged cable. As the tar-impregnated external sheath liberates organic compounds to the sea, the organic matter migrated from the inside of cables cannot be determined. On the other hand, for damaged jacket single-core cables the concentration of corroded copper and/or aluminium increased in the seawater leachant solution. In the case of the aluminium plus copper sheath, the only detected metal was aluminium, while the copper is practically non-corroded. This can be attributed to the galvanic effect when coupled with aluminium. Tests on bioluminescent bacteria and inhibition effects on Daphnia magna indicated a non- toxic effect of all studied undersea power cables (according to pertinent directives). The results provided by the LCA study indicated a low potential impact during the undersea operation of the submarine cable, even for severely damaged cables. The major environmental impact of submarine three-core cables during their use in seabed was associated to the damage category of Ecosystem Quality due mainly to the organic matter and heavy metals emissions (zinc and copper). The impacts due to the electric power transmission were not significant considering the total impact in both studied cases. Also, the effect of the oceanic land use was negligible. (authors)

Environmental assessment of submarine power cables

International Nuclear Information System (INIS)

Isus, Daniel; Martinez, Juan D.; Arteche, Amaya; Del Rio, Carmen; Madina, Virginia

2011-03-01

-impregnated external sheath is not enough as isolation material to avoid the chemicals of galvanized impact on the sea environment. However the HDPE jacket avoids the pollution of sea by the other inside heavy metals like iron and copper. The DOC results showed growing trends in all cases, although the growing rate in broken cable was higher than rate of undamaged cable. As the tar-impregnated external sheath liberates organic compounds to the sea, the organic matter migrated from the inside of cables cannot be determined. On the other hand, for damaged jacket single-core cables the concentration of corroded copper and/or aluminium increased in the seawater leachant solution. In the case of the aluminium plus copper sheath, the only detected metal was aluminium, while the copper is practically non-corroded. This can be attributed to the galvanic effect when coupled with aluminium. Tests on bioluminescent bacteria and inhibition effects on Daphnia magna indicated a non- toxic effect of all studied undersea power cables (according to pertinent directives). The results provided by the LCA study indicated a low potential impact during the undersea operation of the submarine cable, even for severely damaged cables. The major environmental impact of submarine three-core cables during their use in seabed was associated to the damage category of Ecosystem Quality due mainly to the organic matter and heavy metals emissions (zinc and copper). The impacts due to the electric power transmission were not significant considering the total impact in both studied cases. Also, the effect of the oceanic land use was negligible. (authors)

SCICEX: Submarine Arctic Science Program

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Submarine Arctic Science Program, SCICEX, is a federal interagency collaboration among the operational Navy, research agencies, and the marine research community...

The down canyon evolution of submarine sediment density flows

Science.gov (United States)

Parsons, D. R.; Barry, J.; Clare, M. A.; Cartigny, M.; Chaffey, M. R.; Gales, J. A.; Gwiazda, R.; Maier, K. L.; McGann, M.; Paull, C. K.; O'Reilly, T. C.; Rosenberger, K. J.; Simmons, S.; Sumner, E. J.; Talling, P.; Xu, J.

2017-12-01

Submarine density flows, known as turbidity currents, transfer globally significant volumes of terrestrial and shelf sediments, organic carbon, nutrients and fresher-water into the deep ocean. Understanding such flows has wide implications for global organic carbon cycling, the functioning of deep-sea ecosystems, seabed infrastructure hazard assessments, and interpreting geological archives of Earth history. Only river systems transport comparable volumes of sediment over such large areas of the globe. Despite their clear importance, there are remarkably few direct measurements of these oceanic turbidity currents in action. Here we present results from the multi-institution Coordinated Canyon Experiment (CCE) which deployed multiple moorings along the axis of Monterey Canyon (offshore California). An array of six moorings, with downward looking acoustic Doppler current profilers (ADCP) were positioned along the canyon axis from 290 m to 1850 m water depth. The ADCPs reveal the internal flow structure of submarine density flows at each site. We use a novel inversion method to reconstruct the suspended sediment concentration and flow stratification field during each event. Together the six moorings provide the first ever views of the internal structural evolution of turbidity current events as they evolve down system. Across the total 18-month period of deployment at least 15 submarine sediment density flows were measured with velocities up to 8.1 m/sec, with three of these flows extending 50 kms down the canyon beyond the 1850 m water depth mooring. We use these novel data to highlight the controls on ignition, interval structure and collapse of individual events and discuss the implications for the functioning and deposits produced by these enigmatic flows.

Meta-Analysis of Data from the Submarine Ventilation Doctrine Test Program

National Research Council Canada - National Science Library

Hoover, J

1998-01-01

.... The Submarine Ventilation Doctrine Test Program was developed to address submarine-specific issues regarding the use of ventilation systems to control smoke and heat movement, maintain habitability...

Displaying Uncertainty: A Comparison Between Submarine Subject Matter Experts

Science.gov (United States)

2007-03-01

known as the “submarine capital of the world” and is the home for many of the schools relating to the submarine service. The administering officer for...and Woods, D. D. (1988). Aiding Human Performance: I. Cognitive Analysis, Le Travail Humain 51(1), 39-64. Roth, E. M., Patterson, E. S., and Mumaw

History of Military Psychology at the U. S. Naval Submarine Medical Research Laboratory

Science.gov (United States)

1979-10-23

the first nuclear submarine, were gigantic increases in the environmental demands imposed upon the submarine crewmembers. Some of these changes had to...urgency for an empirical determination of the maximum duration a submarine could remain submerged before debilitative symptoms appeared in significant

Situation awareness measures for simulated submarine track management.

Science.gov (United States)

Loft, Shayne; Bowden, Vanessa; Braithwaite, Janelle; Morrell, Daniel B; Huf, Samuel; Durso, Francis T

2015-03-01

The aim of this study was to examine whether the Situation Present Assessment Method (SPAM) and the Situation Awareness Global Assessment Technique (SAGAT) predict incremental variance in performance on a simulated submarine track management task and to measure the potential disruptive effect of these situation awareness (SA) measures. Submarine track managers use various displays to localize and track contacts detected by own-ship sensors. The measurement of SA is crucial for designing effective submarine display interfaces and training programs. Participants monitored a tactical display and sonar bearing-history display to track the cumulative behaviors of contacts in relationship to own-ship position and landmarks. SPAM (or SAGAT) and the Air Traffic Workload Input Technique (ATWIT) were administered during each scenario, and the NASA Task Load Index (NASA-TLX) and Situation Awareness Rating Technique were administered postscenario. SPAM and SAGAT predicted variance in performance after controlling for subjective measures of SA and workload, and SA for past information was a stronger predictor than SA for current/future information. The NASA-TLX predicted performance on some tasks. Only SAGAT predicted variance in performance on all three tasks but marginally increased subjective workload. SPAM, SAGAT, and the NASA-TLX can predict unique variance in submarine track management performance. SAGAT marginally increased subjective workload, but this increase did not lead to any performance decrement. Defense researchers have identified SPAM as an alternative to SAGAT because it would not require field exercises involving submarines to be paused. SPAM was not disruptive, but it is potentially problematic that SPAM did not predict variance in all three performance tasks. © 2014, Human Factors and Ergonomics Society.

Risk factors for dermatitis in submariners during a submerged patrol: an observational cohort study.

Science.gov (United States)

Flaxman, Amy; Allen, Elizabeth; Lindemann, Claudia; Yamaguchi, Yuko; O'Shea, Matthew K; Fallowfield, Joanne L; Lindsay, Michael; Gunner, Frances; Knox, Kyle; Wyllie, David H

2016-06-02

The aim of this pilot study was to determine risk factors, including Staphylococcus aureus nasal carriage, for dermatitis in submariners during a submarine patrol. 36 submariners undertaking a submerged 6-week patrol participated in the study. Severity of dermatitis and its impact was assessed using visual analogue scales and questionnaires at baseline and weekly throughout the patrol. S. aureus carriage levels in submariners were determined by nasal swabbing at baseline and shortly before disembarking the submarine. Occurrence of any skin or soft tissue infections (SSTI) were reported to the medical officer and swabs of the area were taken for subsequent analysis. S. aureus carriers were significantly more likely than non-carriers to have previously received treatment for a cutaneous abscess (39% vs 5%, OR=13 (95% CI 1.3 to 130)) with a trend to being submariners longer (p=0.051). Skin scores at baseline and on patrol were not significantly associated with carriage status. Higher dermatitis scores were observed in those who had been submariners longer (p=0.045). Smoking and allergies were not found to be linked to carriage status or skin health score in this cohort. This small pilot study investigates S. aureus carriage status and skin health in submariners. Length of submarine service but not S. aureus carriage was identified as a risk factor for worsening skin health in this small cohort during a 6-week patrol. This does not support S. aureus decolonisation to improve skin health in this population. Further investigation into causes of dermatitis in submariners is required. This data supports a better understanding of the potential impact of exposure to environmental factors that could affect skin health in submariners. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

An Air Quality Assessment Onboard an Oberon Class Submarine: HMCS Okanagan

National Research Council Canada - National Science Library

Severs, Y

2000-01-01

... submarine to determine if the atmosphere complied with Air Purification Standard BR 1326. The objective of the study was to obtain information to assist in developing plans for future submarine air quality management...

An air quality assessment onboard an Oberon class submarine : HMCS Okanagan

International Nuclear Information System (INIS)

Severs, Y.D.; Sabiston, B.H.

2000-09-01

The Defence and Civil Institute of Environmental Medicine (DCIEM) re-examined the air quality on an Oberon class submarine, the HMCS Okanagan, to determine if the atmosphere complied with Air Purification Standard BR 1326. The main objective of the assessment was to help in the development of future submarine air quality management. The information obtained from the Oberon class submarine could be readily applied to the Victoria class submarines. The assessment involved a trial aboard an Oberon under patrol conditions. The functional and detection capabilities of analytical air monitoring instruments were assessed for a 24-hour period to obtain data regarding the contaminants onboard the submarine. A profile of carbon dioxide accumulation and oxygen consumption was determined. This was followed by an assessment of the effectiveness of air purification such as carbon dioxide scrubbing, oxygen generation and snorting. Carbon monoxide was also monitored and carboxyhemoglobin was measured in both smokers and non-smokers. In order to determine if the sanitary or electrical systems, or engine exhaust posed any danger, ammonia, ozone and nitrous compounds were also measured. In addition, hydrogen, arsine and stibene were monitored to determine any possible danger from charging batteries. The health risks associated with aerosolized particles from cooking, smoking and exhaust gases were also measured. Results showed that all contaminants were within allowable limits. However, the study also confirmed that air purification measures on diesel submarines are minimal and poorly placed and that there is a lack of exhaust ventilation. Poor air exchange was worsened by compartmentalization and blackout curtains. Several recommendations were proposed to improve the management of air quality in Victoria class submarines. 18 refs., 2 tabs., 5 figs

An air quality assessment onboard an Oberon class submarine : HMCS Okanagan

Energy Technology Data Exchange (ETDEWEB)

Severs, Y.D.; Sabiston, B.H.

2000-09-01

The Defence and Civil Institute of Environmental Medicine (DCIEM) re-examined the air quality on an Oberon class submarine, the HMCS Okanagan, to determine if the atmosphere complied with Air Purification Standard BR 1326. The main objective of the assessment was to help in the development of future submarine air quality management. The information obtained from the Oberon class submarine could be readily applied to the Victoria class submarines. The assessment involved a trial aboard an Oberon under patrol conditions. The functional and detection capabilities of analytical air monitoring instruments were assessed for a 24-hour period to obtain data regarding the contaminants onboard the submarine. A profile of carbon dioxide accumulation and oxygen consumption was determined. This was followed by an assessment of the effectiveness of air purification such as carbon dioxide scrubbing, oxygen generation and snorting. Carbon monoxide was also monitored and carboxyhemoglobin was measured in both smokers and non-smokers. In order to determine if the sanitary or electrical systems, or engine exhaust posed any danger, ammonia, ozone and nitrous compounds were also measured. In addition, hydrogen, arsine and stibene were monitored to determine any possible danger from charging batteries. The health risks associated with aerosolized particles from cooking, smoking and exhaust gases were also measured. Results showed that all contaminants were within allowable limits. However, the study also confirmed that air purification measures on diesel submarines are minimal and poorly placed and that there is a lack of exhaust ventilation. Poor air exchange was worsened by compartmentalization and blackout curtains. Several recommendations were proposed to improve the management of air quality in Victoria class submarines. 18 refs., 2 tabs., 5 figs.

Exploration of submarine wake and powering performance using CFD method

International Nuclear Information System (INIS)

Huizhi, Y.; Hongcui, S.; Nan, Z.; Renyou, Y.; Liangmei, Y.

2005-01-01

In response to the needs of better design and less time, Computational Fluid Dynamic(CFD) methods have become an impartible part in the ship design, especially in the earlier design phases. In this paper FLUENT software was used to predict the wake character and powering performance of submarine at model scale. By an effective combination of the block topology, grid, turbulence model and validation, the simulation scheme was developed and applied to the predictions of multiple designs and optimizations of the earlier submarine design iterations. The incompressible RANS equations with different turbulence models were solved. To handle the block interface between the propeller and submarine stern, sliding girds in multiple blocks were employed, unstructural grids were used in the block around the propeller. Submarine with/without stator and/or propeller were studied. The flow feature, forces and powering performance at various conditions were calculated. The results were compared with experimental data, and a good agreement was obtained. (author)

Fuel-cell-propelled submarine-tanker-system study

International Nuclear Information System (INIS)

Court, K.E.; Kumm, W.H.; O'Callaghan, J.E.

1982-06-01

This report provides a systems analysis of a commercial Arctic Ocean submarine tanker system to carry fossil energy to markets. The submarine is to be propelled by a modular Phosphoric Acid Fuel Cell system. The power level is 20 Megawatts. The DOE developed electric utility type fuel cell will be fueled with methanol. Oxidant will be provided from a liquid oxygen tank carried onboard. The twin screw submarine tanker design is sized at 165,000 deadweight tons and the study includes costs and an economic analysis of the transport system of 6 ships. The route will be under the polar icecap from a loading terminal located off Prudhoe Bay, Alaska to a transshipment facility postulated to be in a Norwegian fjord. The system throughput of the gas-fed methanol cargo will be 450,000 barrels per day. The total delivered cost of the methanol including well head purchase price of natural gas, methanol production, and shipping would be $25/bbl from Alaska to the US East Coast. Of this, the shipping cost is $6.80/bbl. All costs in 1981 dollars

Formation of submarine gas hydrates

Energy Technology Data Exchange (ETDEWEB)

Soloviev, V.; Ginsburg, G.D. (Reserch Institute of Geology and Mineral Resources of the Ocean ' ' VNII Okeangeologia' ' , St. Petersburg (Russian Federation))

1994-03-01

Submarine gas hydrates have been discoverd in the course of deep-sea drilling (DSDP and ODP) and bottom sampling in many offshore regions. This paper reports on expeditions carried out in the Black, Caspian and Okhotsk Seas. Gas hydrate accumulations were discovered and investigated in all these areas. The data and an analysis of the results of the deep-sea drilling programme suggest that the infiltration of gas-bearing fluids is a necessary condition for gas hydrate accumulation. This is confirmed by geological observations at three scale levels. Firstly, hydrates in cores are usually associated with comparatively coarse-grained, permeable sediments as well as voids and fractures. Secondly, hydrate accumulations are controlled by permeable geological structures, i.e. faults, diapirs, mud volcanos as well as layered sequences. Thirdly, in the worldwide scale, hydrate accumulations are characteristic of continental slopes and rises and intra-continental seas where submarine seepages also are widespread. Both biogenic and catagenic gas may occur, and the gas sources may be located at various distances from the accumulation. Gas hydrates presumably originate from water-dissolved gas. The possibility of a transition from dissolved gas into hydrate is confirmed by experimental data. Shallow gas hydrate accumulations associated with gas-bearing fluid plumes are the most convenient features for the study of submarine hydrate formation in general. These accumulations are known from the Black, Caspian and Okhotsk Seas, the Gulf of Mexico and off northern California. (au) (24 refs.)

Total Magnetic Field Signatures over Submarine HVDC Power Cables

Science.gov (United States)

Johnson, R. M.; Tchernychev, M.; Johnston, J. M.; Tryggestad, J.

2013-12-01

Mikhail Tchernychev, Geometrics, Inc. Ross Johnson, Geometrics, Inc. Jeff Johnston, Geometrics, Inc. High Voltage Direct Current (HVDC) technology is widely used to transmit electrical power over considerable distances using submarine cables. The most commonly known examples are the HVDC cable between Italy and Greece (160 km), Victoria-Tasmania (300 km), New Jersey - Long Island (82 km) and the Transbay cable (Pittsburg, California - San-Francisco). These cables are inspected periodically and their location and burial depth verified. This inspection applies to live and idle cables; in particular a survey company could be required to locate pieces of a dead cable for subsequent removal from the sea floor. Most HVDC cables produce a constant magnetic field; therefore one of the possible survey tools would be Marine Total Field Magnetometer. We present mathematical expressions of the expected magnetic fields and compare them with fields observed during actual surveys. We also compare these anomalies fields with magnetic fields produced by other long objects, such as submarine pipelines The data processing techniques are discussed. There include the use of Analytic Signal and direct modeling of Total Magnetic Field. The Analytic Signal analysis can be adapted using ground truth where available, but the total field allows better discrimination of the cable parameters, in particular to distinguish between live and idle cable. Use of a Transverse Gradiometer (TVG) allows for easy discrimination between cable and pipe line objects. Considerable magnetic gradient is present in the case of a pipeline whereas there is less gradient for the DC power cable. Thus the TVG is used to validate assumptions made during the data interpretation process. Data obtained during the TVG surveys suggest that the magnetic field of a live HVDC cable is described by an expression for two infinite long wires carrying current in opposite directions.

Representing distributed cognition in complex systems: how a submarine returns to periscope depth.

Science.gov (United States)

Stanton, Neville A

2014-01-01

This paper presents the Event Analysis of Systemic Teamwork (EAST) method as a means of modelling distributed cognition in systems. The method comprises three network models (i.e. task, social and information) and their combination. This method was applied to the interactions between the sound room and control room in a submarine, following the activities of returning the submarine to periscope depth. This paper demonstrates three main developments in EAST. First, building the network models directly, without reference to the intervening methods. Second, the application of analysis metrics to all three networks. Third, the combination of the aforementioned networks in different ways to gain a broader understanding of the distributed cognition. Analyses have shown that EAST can be used to gain both qualitative and quantitative insights into distributed cognition. Future research should focus on the analyses of network resilience and modelling alternative versions of a system.

Submarine canyons off Madras Coast

Digital Repository Service at National Institute of Oceanography (India)

Setty, M.G.A.P.

Submarine canyons off the coast of Madras, Tamil Nadu, India were studied during cruise of @iINS Kistna@@ as part of the IIOE programme They consist of hill-like projections and V-shaped valleys Their other features are also reported...

Assessing potential impacts of energized submarine power cables on crab harvests

Science.gov (United States)

Love, Milton S.; Nishimoto, Mary M.; Clark, Scott; McCrea, Merit; Bull, Ann Scarborough

2017-12-01

Offshore renewable energy facilities transmit electricity to shore through submarine power cables. Electromagnetic field emissions (EMFs) are generated from the transmission of electricity through these cables, such as the AC inter-array (between unit) and AC export (to shore) cables often used in offshore energy production. The EMF has both an electric component and a magnetic component. While sheathing can block the direct electric field, the magnetic field is not blocked. A concern raised by fishermen on the Pacific Coast of North America is that commercially important Dungeness crab (Metacarcinus magister Dana, 1852)) might not cross over an energized submarine power cable to enter a baited crab trap, thus potentially reducing their catch. The presence of operating energized cables off southern California and in Puget Sound (cables that are comparable to those within the arrays of existing offshore wind energy devices) allowed us to conduct experiments on how energized power cables might affect the harvesting of both M. magister and another commercially important crab species, Cancer productus Randall, 1839. In this study we tested the questions: 1) Is the catchability of crabs reduced if these animals must traverse an energized power cable to enter a trap and 2) if crabs preferentially do not cross an energized cable, is it the cable structure or the EMF emitted from that cable that deters crabs from crossing? In field experiments off southern California and in Puget Sound, crabs were given a choice of walking over an energized power cable to a baited trap or walking directly away from that cable to a second baited trap. Based on our research we found no evidence that the EMF emitted by energized submarine power cables influenced the catchability of these two species of commercially important crabs. In addition, there was no difference in the crabs' responses to lightly buried versus unburied cables. We did observe that, regardless of the position of the cable

Submarine landslides: advances and challenges

Science.gov (United States)

Locat, Jacques; Lee, Homa J.

2002-01-01

Due to the recent development of well-integrated surveying techniques of the sea floor, significant improvements were achieved in mapping and describing the morphology and architecture of submarine mass movements. Except for the occurrence of turbidity currents, the aquatic environment (marine and fresh water) experiences the same type of mass failure as that found on land. Submarine mass movements, however, can have run-out distances in excess of 100 km, so their impact on any offshore activity needs to be integrated over a wide area. This great mobility of submarinemass movements is still not very well understood, particularly for cases like the far-reaching debris flows mapped on the Mississippi Fan and the large submarine rock avalanches found around many volcanic islands. A major challenge ahead is the integration of mass movement mechanics in an appropriate evaluation of the hazard so that proper risk assessment methodologies can be developed and implemented for various human activities offshore, including the development of natural resources and the establishment of reliable communication corridors. Key words : submarine slides, hazards, risk assessment, morphology, mobility, tsunami. Le dveloppement rcent de techniques de levs hydrograhiques pour les fonds marins nous a permis d'atteindre une qualit ingale dans la cartographie et la description des glissements sous marins. l'exception des courants de turbidit, on retrouve dans le domaine aquatique les mmes types de mouvements de terrain que sur terre. Par contre, les glissements sous-marins peuvent atteindre des distances excdant 100 km de telle sorte que leur impact sur les activits offshore doit tre pris en compte sur degrandes tendues. La grande mobilit des glissements sous-marins n'est pas encore bien comprise, comme pour le cas des coules dedbris cartographies sur le cne du Mississippi ainsi que pour les grandes avalanches rocheuses sous-marines retrouves au pourtour des les volcaniques. Un dfi majeur

Airborne Radar Search for Diesel Submarines

National Research Council Canada - National Science Library

Pilnick, Steven E; Landa, Jose

2005-01-01

.... In this research, a detection rate model is developed to analyze the effectiveness of airborne radar search for a diesel submarine assumed to be intermittently operating with periscopes or masts...

Study on the locational criteria for submarine rock repositories of low and medium level radioactive wastes

Energy Technology Data Exchange (ETDEWEB)

Kim, G H; Kang, W J; Kim, T J. and others [Chungnam National Univ., Taejon (Korea, Republic of)

1992-01-15

Submarine repositories have significant advantages over their land counterparts locating close to the areas of daily human activities. Consequently, the construction of submarine repositories on the vast continental shelves around Korean seas is considered to be highly positive. In this context, the development of locational criteria primarily targeting the safety of submarine rock repositories is very important.The contents of the present study are: analyzing characteristics of marine environment: Search of potential hazards to, and environmental impact by, the submarine repositories; Investigation of the oceanographic, geochemical, ecological and sedimentological characteristics of estuaries and coastal seas. Locating potential hazards to submarine repositories by: Bibliographical search of accidents leading to the destruction of submarine structures by turbidity currents and other potentials; Review of turbidity currents. Consideration of environmental impact caused by submarine repositories: Logistics to minimize the environmental impacts in site selection; Removal and dispersion processes of radionuclides in sea water. Analyses of oceanographical characteristics of, and hazard potentials in, the Korean seas. Evaluation of the MOST 91-7 criteria for applicability to submarine repositories and the subsequent proposition of additional criteria.

Study on the locational criteria for submarine rock repositories of low and medium level radioactive wastes

International Nuclear Information System (INIS)

Kim, G. H.; Kang, W. J.; Kim, T. J. and others

1992-01-01

Submarine repositories have significant advantages over their land counterparts locating close to the areas of daily human activities. Consequently, the construction of submarine repositories on the vast continental shelves around Korean seas is considered to be highly positive. In this context, the development of locational criteria primarily targeting the safety of submarine rock repositories is very important.The contents of the present study are: analyzing characteristics of marine environment: Search of potential hazards to, and environmental impact by, the submarine repositories; Investigation of the oceanographic, geochemical, ecological and sedimentological characteristics of estuaries and coastal seas. Locating potential hazards to submarine repositories by: Bibliographical search of accidents leading to the destruction of submarine structures by turbidity currents and other potentials; Review of turbidity currents. Consideration of environmental impact caused by submarine repositories: Logistics to minimize the environmental impacts in site selection; Removal and dispersion processes of radionuclides in sea water. Analyses of oceanographical characteristics of, and hazard potentials in, the Korean seas. Evaluation of the MOST 91-7 criteria for applicability to submarine repositories and the subsequent proposition of additional criteria

Observations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii

Science.gov (United States)

Swarzenski, Peter W.; Dulai, H.; Kroeger, K.D.; Smith, C.G.; Dimova, N.; Storlazzi, C. D.; Prouty, N.G.; Gingerich, S.B.; Glenn, C. R.

2016-01-01

Study regionThe study region encompasses the nearshore, coastal waters off west Maui, Hawaii. Here abundant groundwater—that carries with it a strong land-based fingerprint—discharges into the coastal waters and over a coral reef.Study focusCoastal groundwater discharge is a ubiquitous hydrologic feature that has been shown to impact nearshore ecosystems and material budgets. A unique combined geochemical tracer and oceanographic time-series study addressed rates and oceanic forcings of submarine groundwater discharge at a submarine spring site off west Maui, Hawaii.New hydrological insights for the regionEstimates of submarine groundwater discharge were derived for a primary vent site and surrounding coastal waters off west Maui, Hawaii using an excess 222Rn (t1/2 = 3.8 d) mass balance model. Such estimates were complemented with a novel thoron (220Rn,t1/2 = 56 s) groundwater discharge tracer application, as well as oceanographic time series and thermal infrared imagery analyses. In combination, this suite of techniques provides new insight into the connectivity of the coastal aquifer with the near-shore ocean and examines the physical drivers of submarine groundwater discharge. Lastly, submarine groundwater discharge derived constituent concentrations were tabulated and compared to surrounding seawater concentrations. Such work has implications for the management of coastal aquifers and downstream nearshore ecosystems that respond to sustained constituent loadings via this submarine route.

Indian, Japanese, And U.S. Responses To Chinese Submarine Modernization

Science.gov (United States)

2016-03-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited INDIAN, JAPANESE ...DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE INDIAN, JAPANESE , AND U.S. RESPONSES TO CHINESE SUBMARINE MODERNIZATION 5. FUNDING NUMBERS 6...is unlimited INDIAN, JAPANESE , AND U.S. RESPONSES TO CHINESE SUBMARINE MODERNIZATION David E. Kiser Lieutenant Commander, United States

Exploring the submarine Graham Bank in the Sicily Channel

Directory of Open Access Journals (Sweden)

Mauro Coltelli

2016-05-01

Full Text Available In the Sicily Channel, volcanic activity has been concentrated mainly on the Pantelleria and Linosa islands, while minor submarine volcanism took place in the Adventure, Graham and Nameless banks. The volcanic activity spanned mostly during Plio-Pleistocene, however, historical submarine eruptions occurred in 1831 on the Graham Bank and in 1891 offshore Pantelleria Island. On the Graham Bank, 25 miles SW of Sciacca, the 1831 eruption formed the short-lived Ferdinandea Island that represents the only Italian volcano active in historical times currently almost completely unknown and not yet monitored. Moreover, most of the Sicily Channel seismicity is concentrated along a broad NS belt extending from the Graham Bank to Lampedusa Island. In 2012, the Istituto Nazionale di Geofisica e Vulcanologia (INGV carried out a multidisciplinary oceanographic cruise, named “Ferdinandea 2012”, the preliminary results of which represent the aim of this paper. The cruise goal was the mapping of the morpho-structural features of some submarine volcanic centres located in the northwestern side of the Sicily Channel and the temporary recording of their seismic and degassing activity. During the cruise, three OBS/Hs (ocean bottom seismometer with hydrophone were deployed near the Graham, Nerita and Terribile submarine banks. During the following 9 months they have recorded several seismo-acoustic signals produced by both tectonic and volcanic sources. A high-resolution bathymetric survey was achieved on the Graham Bank and on the surrounding submarine volcanic centres. A widespread and voluminous gas bubbles emission was observed by both multibeam sonar echoes and a ROV (remotely operated vehicle along the NW side of the Graham Bank, where gas and seafloor samples were also collected.

Anaphylaxis, Intra-Abdominal Infections, Skin Lacerations, and Behavioral Emergencies: A Literature Review of Austere Analogs for a near Earth Asteroid Mission

Science.gov (United States)

Chough, Natacha G.; Watkins, Sharmi; Menon, Anil S.

2012-01-01

As space exploration is directed towards destinations beyond low-Earth orbit, the consequent new set of medical risks will drive requirements for new capabilities and more resources to ensure crew health. The Space Medicine Exploration Medical Conditions List (SMEMCL), developed by the Exploration Medical Capability element of the Human Research Program, addresses the risk of "unacceptable health and mission outcomes due to limitations of in-flight medical capabilities". It itemizes 85 evidence-based clinical requirements for eight different mission profiles and identifies conditions warranting further research and technology development. Each condition is given a clinical priority for each mission profile. Four conditions -- intra-abdominal infections, skin lacerations, anaphylaxis, and behavioral emergencies -- were selected as a starting point for analysis. A systematic literature review was performed to understand how these conditions are treated in austere, limited-resource, space-analog environments (i.e., high-altitude and mountain environments, submarines, military deployments, Antarctica, isolated wilderness environments, in-flight environments, and remote, resource-poor, rural environments). These environments serve as analogs to spaceflight because of their shared characteristics (limited medical resources, delay in communication, confined living quarters, difficulty with resupply, variable time to evacuation). Treatment of these four medical conditions in austere environments provides insight into medical equipment and training requirements for exploration-class missions.

A local area network and information management system for a submarine overhaul facility

OpenAIRE

Bushmire, Jeffrey D

1990-01-01

A preliminary design of a local area network for a submarine overhaul facility is developed using System Engineering concepts. SOFLAN, the Submarine Overhaul Facility Local Area Network, is necessary to provide more timely and accurate information to submarine overhaul managers in order to decrease the overhaul time period and become more competitive. The network is a microcomputer based system following the Ethernet and IEEE 802.3 standards with a server .. client architecture. SOFLAN serves...

A submarine volcanic eruption leads to a novel microbial habitat.

Science.gov (United States)

Danovaro, Roberto; Canals, Miquel; Tangherlini, Michael; Dell'Anno, Antonio; Gambi, Cristina; Lastras, Galderic; Amblas, David; Sanchez-Vidal, Anna; Frigola, Jaime; Calafat, Antoni M; Pedrosa-Pàmies, Rut; Rivera, Jesus; Rayo, Xavier; Corinaldesi, Cinzia

2017-04-24

Submarine volcanic eruptions are major catastrophic events that allow investigation of the colonization mechanisms of newly formed seabed. We explored the seafloor after the eruption of the Tagoro submarine volcano off El Hierro Island, Canary Archipelago. Near the summit of the volcanic cone, at about 130 m depth, we found massive mats of long, white filaments that we named Venus's hair. Microscopic and molecular analyses revealed that these filaments are made of bacterial trichomes enveloped within a sheath and colonized by epibiotic bacteria. Metagenomic analyses of the filaments identified a new genus and species of the order Thiotrichales, Thiolava veneris. Venus's hair shows an unprecedented array of metabolic pathways, spanning from the exploitation of organic and inorganic carbon released by volcanic degassing to the uptake of sulfur and nitrogen compounds. This unique metabolic plasticity provides key competitive advantages for the colonization of the new habitat created by the submarine eruption. A specialized and highly diverse food web thrives on the complex three-dimensional habitat formed by these microorganisms, providing evidence that Venus's hair can drive the restart of biological systems after submarine volcanic eruptions.

Mission Adaptive UAS Platform for Earth Science Resource Assessment

Science.gov (United States)

Dunagan, S.; Fladeland, M.; Ippolito, C.; Knudson, M.

2015-01-01

NASA Ames Research Center has led a number of important Earth science remote sensing missions including several directed at the assessment of natural resources. A key asset for accessing high risk airspace has been the 180 kg class SIERRA UAS platform, providing mission durations of up to 8 hrs at altitudes up to 3 km. Recent improvements to this mission capability are embodied in the incipient SIERRA-B variant. Two resource mapping problems having unusual mission characteristics requiring a mission adaptive capability are explored here. One example involves the requirement for careful control over solar angle geometry for passive reflectance measurements. This challenges the management of resources in the coastal ocean where solar angle combines with sea state to produce surface glint that can obscure the ocean color signal. Furthermore, as for all scanning imager applications, the primary flight control priority to fly the UAS directly to the next waypoint should compromise with the requirement to minimize roll and crab effects in the imagery. A second example involves the mapping of natural resources in the Earth's crust using precision magnetometry. In this case the vehicle flight path must be oriented to optimize magnetic flux gradients over a spatial domain having continually emerging features, while optimizing the efficiency of the spatial mapping task. These requirements were highlighted in several recent Earth Science missions including the October 2013 OCEANIA mission directed at improving the capability for hyperspectral reflectance measurements in the coastal ocean, and the Surprise Valley Mission directed at mapping sub-surface mineral composition and faults, using high-sensitivity magentometry. This paper reports the development of specific aircraft control approaches to incorporate the unusual and demanding requirements to manage solar angle, aircraft attitude and flight path orientation, and efficient (directly geo-rectified) surface and sub

Water-Exit Process Modeling and Added-Mass Calculation of the Submarine-Launched Missile

Directory of Open Access Journals (Sweden)

Yang Jian

2017-11-01

Full Text Available In the process that the submarine-launched missile exits the water, there is the complex fluid solid coupling phenomenon. Therefore, it is difficult to establish the accurate water-exit dynamic model. In the paper, according to the characteristics of the water-exit motion, based on the traditional method of added mass, considering the added mass changing rate, the water-exit dynamic model is established. And with help of the CFX fluid simulation software, a new calculation method of the added mass that is suit for submarine-launched missile is proposed, which can effectively solve the problem of fluid solid coupling in modeling process. Then by the new calculation method, the change law of the added mass in water-exit process of the missile is obtained. In simulated analysis, for the water-exit process of the missile, by comparing the results of the numerical simulation and the calculation of theoretical model, the effectiveness of the new added mass calculation method and the accuracy of the water-exit dynamic model that considers the added mass changing rate are verified.

Nearshore circulation revealed by wastewater discharge from a submarine outfall, Aveiro Coast, Portugal

Directory of Open Access Journals (Sweden)

J. Figueiredo da Silva

2002-01-01

Full Text Available The morphological and climatic conditions of the Atlantic coast of northern Portugal result in a prevailing upwelling circulation over the continental shelf. A submarine outfall releases wastewater into the ocean c. 3 km directly offshore (at ∼16 m water depth from S. Jacinto, 5 km to the north of the inlet to the estuarine coastal lagoon system of the Ria de Aveiro. The buoyant plume has a distinctive reddish brown colour and is clearly visible at the water surface. The transport and dispersion of the plume was monitored by airborne photography and by in situ water sampling. Results revealed the surface currents present and water mass fronts in the nearshore zone of the Aveiro coast. During the spring and summer, the plume was not transported offshore in the manner expected by the upwelling shelf circulation. Instead, it was commonly observed to be transported alongshore with the prevailing southerly circulation or with an onshore component. The transport to the south caused the outfall plume to interact with the circulation associated with the tidal currents generated in the inlet channel to the Ria de Aveiro. The observations suggest that the trophic status of the Ria de Aveiro is unlikely to change because of the operation of the submarine outfall. Furthermore, this study demonstrates how simple observations of wastewater discharge from a submarine outfall can be used to improve understanding of nearshore circulation. Keywords: water circulation, upwelling, ocean outfall, remote sensing, eutrophication, Ria de Aveiro

Computer graphics aid mission operations. [NASA missions

Science.gov (United States)

Jeletic, James F.

1990-01-01

The application of computer graphics techniques in NASA space missions is reviewed. Telemetric monitoring of the Space Shuttle and its components is discussed, noting the use of computer graphics for real-time visualization problems in the retrieval and repair of the Solar Maximum Mission. The use of the world map display for determining a spacecraft's location above the earth and the problem of verifying the relative position and orientation of spacecraft to celestial bodies are examined. The Flight Dynamics/STS Three-dimensional Monitoring System and the Trajectroy Computations and Orbital Products System world map display are described, emphasizing Space Shuttle applications. Also, consideration is given to the development of monitoring systems such as the Shuttle Payloads Mission Monitoring System and the Attitude Heads-Up Display and the use of the NASA-Goddard Two-dimensional Graphics Monitoring System during Shuttle missions and to support the Hubble Space Telescope.

Advance directives and personal identity: what is the problem?

Science.gov (United States)

Furberg, Elisabeth

2012-02-01

The personal identity problem expresses the worry that due to disrupted psychological continuity, one person's advance directive could be used to determine the care of a different person. Even ethicists, who strongly question the possibility of the scenario depicted by the proponents of the personal identity problem, often consider it to be a very potent objection to the use of advance directives. Aiming to question this assumption, I, in this paper, discuss the personal identity problem's relevance to the moral force of advance directives. By putting the personal identity argument in relation to two different normative frameworks, I aim to show that whether or not the personal identity problem is relevant to the moral force of advance directives, and further, in what way it is relevant, depends entirely on what normative reasons we have for respecting advance directives in the first place.

Hybrid Intelligent Control for Submarine Stabilization

Directory of Open Access Journals (Sweden)

Minghui Wang

2013-05-01

Full Text Available Abstract While sailing near the sea surface, submarines will often undergo rolling motion caused by wave disturbance. Fierce rolling motion seriously affects their normal operation and even threatens their security. We propose a new control method for roll stabilization. This paper studies hybrid intelligent control combining a fuzzy control, a neural network and extension control technology. Every control strategy can achieve the ideal control effect within the scope of its effective control. The neuro-fuzzy control strategy is used to improve the robustness of the controller. The speed control strategy and the course control strategy are conducted to extend the control range. The paper also proposes the design of the controller and carries out the simulation experiment in different sea conditions. The simulation results show that the control method proposed can indeed effectively improve the control performance of submarine stabilization.

Observations of nearshore groundwater discharge: Kahekili Beach Park submarine springs, Maui, Hawaii

Directory of Open Access Journals (Sweden)

P.W. Swarzenski

2017-06-01

New hydrological insights for the region: Estimates of submarine groundwater discharge were derived for a primary vent site and surrounding coastal waters off west Maui, Hawaii using an excess 222Rn (t1/2 = 3.8 d mass balance model. Such estimates were complemented with a novel thoron (220Rn, t1/2 = 56 s groundwater discharge tracer application, as well as oceanographic time series and thermal infrared imagery analyses. In combination, this suite of techniques provides new insight into the connectivity of the coastal aquifer with the near-shore ocean and examines the physical drivers of submarine groundwater discharge. Lastly, submarine groundwater discharge derived constituent concentrations were tabulated and compared to surrounding seawater concentrations. Such work has implications for the management of coastal aquifers and downstream nearshore ecosystems that respond to sustained constituent loadings via this submarine route.

Interconnection of the Keys north of the country with the National Electro energetic System (SEN) through a submarine cable

International Nuclear Information System (INIS)

Sánchez Yañez, Pablo

2017-01-01

Most of the keys of the north of the country have a high potential for tourism Sun and beach, which is why each has an associated infrastructure that allows hotels have the necessary quality standards. Within this infrastructure the continuous electrical service must have each hotel to meet the needs of tourists stands. Today the keys are isolated from the SEN and electrical service is supplied by generators. These groups feed on fuel and diesel, and generate polluting gases near where the major hotel groups are. The problems in transporting fuel and pollution they generate have led to begin to analyze different ways of providing electric service stably in the keys. One possible option to address the problems generated by power generators in an isolated system is to interconnect the cay with SEN. This connection can be made in three ways; by airlines, underground cables or submarine cables. The airlines in the tourist areas are discarded because they affect the visuality this is why variants of underground cables or submarines are almost always handled. The proposal is to interconnect the keys with submarine cable where current conditions do not allow the use of underground cables. This interconnection can meet the demand of the keys stably and more reliably than current conditions. In addition to cases where there is a tourism growth should be no more generators only have a cable with the ability to transfer all the power needed. (author)

Effect of Topography on Subglacial Discharge and Submarine Melting During Tidewater Glacier Retreat

Science.gov (United States)

Amundson, J. M.; Carroll, D.

2018-01-01

To first order, subglacial discharge depends on climate, which determines precipitation fluxes and glacier mass balance, and the rate of glacier volume change. For tidewater glaciers, large and rapid changes in glacier volume can occur independent of climate change due to strong glacier dynamic feedbacks. Using an idealized tidewater glacier model, we show that these feedbacks produce secular variations in subglacial discharge that are influenced by subglacial topography. Retreat along retrograde bed slopes (into deep water) results in rapid surface lowering and coincident increases in subglacial discharge. Consequently, submarine melting of glacier termini, which depends on subglacial discharge and ocean thermal forcing, also increases during retreat into deep water. Both subglacial discharge and submarine melting subsequently decrease as glacier termini retreat out of deep water and approach new steady state equilibria. In our simulations, subglacial discharge reached peaks that were 6-17% higher than preretreat values, with the highest values occurring during retreat from narrow sills, and submarine melting increased by 14% for unstratified fjords and 51% for highly stratified fjords. Our results therefore indicate that submarine melting acts in concert with iceberg calving to cause tidewater glacier termini to be unstable on retrograde beds. The full impact of submarine melting on tidewater glacier stability remains uncertain, however, due to poor understanding of the coupling between submarine melting and iceberg calving.

Stability of submarine slopes in the northern South China Sea: a numerical approach

Science.gov (United States)

Zhang, Liang; Luan, Xiwu

2013-01-01

Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained ( Φ=0) cases. Results show that submarine slopes are stable when the slope is 13° with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes >10°, and >3° for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.

Submarine Volcanology: 1950 to 2050 and Beyond (Invited)

Science.gov (United States)

Delaney, J. R.; Kelley, D. S.

2010-12-01

The vigorous pursuit of submarine volcanism as a major field emerged in the mid 1900’s with the post WWII recognition that there is a Mid-Ocean Ridge System that is a 70,000 km long volcanic mountain chain stretching around the world like the strings on a baseball. By the mid 1960’s it emerged that rocks from volcanic feature were consistently basaltic in character and that they were the direct result of major melting processes associated with rise of much deeper mantle material beneath the spreading ridges in a global plate tectonics framework. More than 60% of the volcanism on the planet occurs in submarine environments. The next major discovery, using the deep diving submarine ALVIN, was in the late 1970’s involving hydrothermal systems near active ridges close to the Galapagos Islands and Baja California. The idea that these vent sites were the locus of major biological productivity based on volcanically-driven chemosynthesis was a fundamental new insight in the deep ocean ecology of our planet. This was a major planetological discovery and was followed within about 15 years with an even more powerful realization: our planet has a vast sub seafloor microbial biosphere thriving in the pores and the cracks of the oceanic crust driven by circulation of modified ocean fluids through large portions of the lithosphere. These organisms are largely supported by degassing and water-rock reactions associated with submarine volcanoes. Some estimates have posited that: 1) these thermally active systems and the chemosynthetic lifestyle are a natural consequence of certain types of planetary evolution, 2) that life may have originated in these systems, and, 3) that the biomass associated with the modern sub seafloor systems rivals most other living carbon on the continents. Indeed, parallel exploration of the outer solar system has lead to propositions that the second moon of Jupiter, Europa, has (or had) a high potential to harbor analogous hydrothermal life forms

Submarine geothermal resources

Science.gov (United States)

Williams, D.L.

1976-01-01

Approximately 20% of the earth's heat loss (or 2 ?? 1012 cal/s) is released through 1% of the earth's surface area and takes the form of hydrothermal discharge from young (Pleistocene or younger) rocks adjacent to active seafloor-spreading centers and submarine volcanic areas. This amount is roughly equivalent to man's present gross energy consumption rate. A sub-seafloor geothermal reservoir, to be exploitable under future economic conditions, will have to be hot, porous, permeable, large, shallow, and near an energy-deficient, populated land mass. Furthermore, the energy must be recoverable using technology achievable at a competitive cost and numerous environmental, legal and institutional problems will have to be overcome. The highest-temperature reservoirs should be found adjacent to the zones of the seafloor extension or volcanism that are subject to high sedimentation rates. The relatively impermeable sediments reduce hydrothermal-discharge flow rates, forcing the heat to be either conducted away or released by high-temperature fluids, both of which lead to reservoir temperatures that can exceed 300??C. There is evidence that the oceanic crust is quite permeable and porous and that it was amenable to deep (3-5 km) penetration by seawater at least some time in the early stages of its evolution. Most of the heat escapes far from land, but there are notable exceptions. For example, in parts of the Gulf of California, thermal gradients in the bottom sediments exceed 1??C/m. In the coastal areas of the Gulf of California, where electricity and fresh water are at a premium, this potential resource lies in shallow water (characteristics of these systems before they can be considered a viable resource. Until several of the most promising areas are carefully defined and drilled, the problem will remain unresolved. ?? 1976.

The project of the submarine of nuclear propulsion under the optics of its protagonists: an historical analysis from Geisel to Lula 1974 - 2009

International Nuclear Information System (INIS)

Correa, Fernanda das Gracas

2009-01-01

This work is a historical analysis of the project of construction of the submarine of nuclear propulsion under the optics of the people who direct or had indirectly become involved themselves with it. Geisel undertook a more autonomous type of politics. The Europe started to be the strategical region for the acquisition of nuclear technology. The only favorable country transfer nuclear technology to Brazil was the Federal Republic of Germany (FRG). The idea to construct a nuclear submarine is product of the negotiations between authorities of Brazilian politics and political, diplomatical, scientific and business authorities of the FRG. In 1978, the engineer Othon Luiz Pinheiro da Silva came back to Brazil after completing his doctorate in nuclear technology in the MIT. Commander Othon developed the idea to construct a nuclear submarine in the Brazilian Navy. Due to the events in the national and in the international scenario, Geisel decided to construct the nuclear submarine, but he opted to allow the Brazilian Navy to lead this construction. Although Geisel sketched a project of naval nuclear propulsion, it was the project elaborated by commander Othon which became the nuclear project of the Brazilian Navy. In order to prevent international attention toward this work, Geisel guided it for the subversion. This way, the idea to construct a nuclear submarine ceases to belong to the Brazilian nuclear program to become parallel nuclear program. When Figueiredo became president he kept the diversification politics of partnerships, kept the nuclear Agreement Brazil-FRG in 1975 and kept the project of construction of a nuclear reactor. Figueiredo, after observing the performance of the English nuclear submarines in the south Atlantic and to perceive the real intentions of U.S.A. towards Brazil, Figueiredo decided to support politically and financially and the project of construction of the nuclear submarine. Despite all aversion that Figueiredo had in relation to

Airborne Radar Search for Diesel Submarines (ARSDS)

National Research Council Canada - National Science Library

Pilnick, Steven E; Landa, Jose

2005-01-01

.... In this research, a detection rate model is developed to analyze the effectiveness of an airborne radar search for a diesel submarine assumed to be intermittently operating with periscopes or masts...

PAUT-based defect detection method for submarine pressure hulls

Directory of Open Access Journals (Sweden)

Min-jae Jung

2018-03-01

Full Text Available A submarine has a pressure hull that can withstand high hydraulic pressure and therefore, requires the use of highly advanced shipbuilding technology. When producing a pressure hull, periodic inspection, repair, and maintenance are conducted to maintain its soundness. Of the maintenance methods, Non-Destructive Testing (NDT is the most effective, because it does not damage the target but sustains its original form and function while inspecting internal and external defects. The NDT process to detect defects in the welded parts of the submarine is applied through Magnetic particle Testing (MT to detect surface defects and Ultrasonic Testing (UT and Radiography Testing (RT to detect internal defects. In comparison with RT, UT encounters difficulties in distinguishing the types of defects, can yield different results depending on the skills of the inspector, and stores no inspection record. At the same time, the use of RT gives rise to issues related to worker safety due to radiation exposure. RT is also difficult to apply from the perspectives of the manufacturing of the submarine and economic feasibility. Therefore, in this study, the Phased Array Ultrasonic Testing (PAUT method was applied to propose an inspection method that can address the above disadvantages by designing a probe to enhance the precision of detection of hull defects and the reliability of calculations of defect size. Keywords: Submarine pressure hull, Non-destructive testing, Phased array ultrasonic testing

Submarine paleoseismology based on turbidite records.

Science.gov (United States)

Goldfinger, Chris

2011-01-01

Many of the largest earthquakes are generated at subduction zones or other plate boundary fault systems near enough to the coast that marine environments may record evidence of them. During and shortly after large earthquakes in the coastal and marine environments, a spectrum of evidence may be left behind, mirroring onshore paleoseismic evidence. Shaking or displacement of the seafloor can trigger processes such as turbidity currents, submarine landslides, tsunami (which may be recorded both onshore and offshore), and soft-sediment deformation. Marine sites may also share evidence of fault scarps, colluvial wedges, offset features, and liquefaction or fluid expulsion with their onshore counterparts. This article reviews the use of submarine turbidite deposits for paleoseismology, focuses on the dating and correlation techniques used to establish stratigraphic continuity of marine deposits, and outlines criteria for distinguishing earthquake deposits and the strategies used to acquire suitable samples and data for marine paleoseismology.

Topology Model of the Flow around a Submarine Hull Form

Science.gov (United States)

2015-12-01

UNCLASSIFIED Topology Model of the Flow around a Submarine Hull Form S.-K. Lee Maritime Division Defence Science and Technology Group DST-Group–TR...3177 ABSTRACT A topology model constructed from surface-streamer visualisation describes the flow around a generic conventional submarine hull form at...pure yaw angles of 0 ◦, 10 ◦ and 18 ◦. The model is used to develop equations for sway-force and yaw-moment coefficients which relate to the hull - form

Broaching the Ship: Rethinking Submarines as a Signaling Tool in Naval Diplomacy

Science.gov (United States)

2015-03-01

Bateman , “Perils of the Deep: the Dangers of Submarine Proliferation in the Seas of East Asia,” Asian Security 7, no. 1 (Spring 2011), 64. 89 Brent...Science. London: Routledge, 2012. Bateman , Sam. “Perils of the Deep: The Dangers of Submarine Proliferation in the Seas of East Asia.” Asian Security

Multiple Smaller Missions as a Direct Pathway to Mars Sample Return

Science.gov (United States)

Niles, P. B.; Draper, D. S.; Evans, C. A.; Gibson, E. K.; Graham, L. D.; Jones, J. H.; Lederer, S. M.; Ming, D.; Seaman, C. H.; Archer, P. D.;

Information Assurance as a System of Systems in the Submarine Force

Science.gov (United States)

2013-09-01

Shell SSL Secure Socket Layer SSN Submerged Ship Nuclear STDA Submarine Tactical Display Auxiliary SUBLAN Submarine Local Area Network...Internet Protocol TLS T Transport Layer Security TS-SCI Top Secret-Special Compartment Information TYCOM Type Commander USB Universal...administrators or users. Layer 4 and 5: This is the layer that deals with providing a protected connection via a Secure Socket Layer ( SSL ) and Transport Layer

Biological life support systems for martian missions: some problems and prospects

Science.gov (United States)

Tikhomirov, A. A.; Ushakova, S. A.; Kovaleva, N. P.; Lasseur, C.

Taking into account the experience of scientific researches obtained during experiments in the BIOS - 3 of the Institute of Biophysics of Siberian Branch of Russian Academy of Science (IBP SB RAS) and the MELISSA program (ESA), approaches in creation biological life support systems for a flight period and a fixed-site base of Martian mission are considered. Various alternate variants of designing of elements of BLSS based on use of Chlorella and/or Spirulina, and also greenhouses with higher plants for the flight period of Martian mission are analyzed. For this purpose construction of BLSS ensuring full closure of matter turnover according to gas exchange and water and partial closure on the human's exometabolites is supposed. For the fixed site Martian station BLSS based on use of higher plants with a various degree of closure of internal mass exchange are suggested. Various versions of BLSS configuration and degree of closure of mass exchange depending on duration of Martian mission, the diet type of a crew and some other conditions are considered. Special attention is given to problems of reliability and tolerance of matter turnover processes in BLSS which maintenance is connected, in particular, with additional oxygen reproduction inside a system. Technologies for realization of BLSS of various configurations are offered and justified. The auxiliary role of the physicochemical methods in BLSS functioning both for the flight period and for the crew stay on Mars is justified.

Research on the hydrogeological and geochemical conditions at the coastal area and submarine formations

International Nuclear Information System (INIS)

Tokunaga, Tomochika; Taniguchi, Makoto; Goto, Junji

2003-05-01

One of the major concerns for the high-level radioactive waste disposal is the possibility of the radionuclides to reach biosphere by groundwater flow. Recent research results have shown that the fresh groundwater discharge from subsea formations are widespread phenomena, thus, it is necessary to evaluate the submarine groundwater discharge as possible pathways of contaminant discharge towards the biosphere. It is also important to unravel the groundwater flow and associated material transport at the coastal area and subsea formations. To better understand the groundwater flow processes and the submarine groundwater discharge, we have conducted the hydrological, hydrogeological, geochemical, and numerical modeling studies at the Kurobe alluvial fan and its offshore, Toyama Prefecture, Japan. In this report, the results of the following research activities are presented: 1) Development and application of a method to detect the locations of the submarine groundwater discharge. 2) Development and application of a method to collect uncontaminated groundwater samples from subsea formations. 3) Measurements of submarine groundwater discharge fluxes by automated seepage meter. 4) Hydrological and geochemical studies for groundwater flow at the coastal area. 5) Geochemical studies to understand sources of fresh submarine groundwater discharge. 6) Examination of groundwater flow and submarine groundwater discharge using methane concentration and carbon isotope ratio. 7) Numerical modeling studies for coastal groundwater flow system. (author)

A Nuclear Submarine in the South Atlantic: The Framing of Threats and Deterrence

Directory of Open Access Journals (Sweden)

Mônica Herz

Full Text Available Abstract In this article, we analyse one aspect of Brazilian nuclear policy during the tenure of the Workers Party (2003–2016: the development of a nuclear-propelled submarine. We propose that the project of building a nuclear-propelled submarine has become possible partly because of the mobilisation of a set of arguments for the construction of the South Atlantic as a strategic area, framed in terms of security and development. On the other hand, we contend that the need for a nuclear-propelled submarine is framed through the mobilisation of a specific notion of deterrence. In other words, we claim that the notions of ‘strategic area’, ‘general deterrence’, ‘conventional deterrence’, and ‘deterrence by denial’ can help us analyse the fundamental aspects involved in the framing of the South Atlantic as a security concern, justifying the nuclear-propelled submarine project.

Assessment of Hg Pollution Released from a WWII Submarine Wreck (U-864) by Hg Isotopic Analysis of Sediments and Cancer pagurus Tissues.

Science.gov (United States)

Rua-Ibarz, Ana; Bolea-Fernandez, Eduardo; Maage, Amund; Frantzen, Sylvia; Valdersnes, Stig; Vanhaecke, Frank

2016-10-04

Hg pollution released from the U-864 submarine sunk during WWII and potential introduction of that Hg into the marine food chain have been studied by a combination of quantitative Hg and MeHg determination and Hg isotopic analysis via cold vapor generation multicollector inductively coupled plasma-mass spectrometry (CVG-MC-ICP-MS) in sediment and Cancer pagurus samples. The sediment pollution could be unequivocally linked with the metallic Hg present in the wreck. Crabs were collected at the wreck location and 4 nmi north and south, and their brown and claw meat were analyzed separately. For brown meat, the δ 202 Hg values of the individuals from the wreck location were shifted toward the isotopic signature of the sediment and, thus, the submarine Hg. Such differences were not found for claw meat. The isotope ratio results suggest direct ingestion of metallic Hg by C. pagurus but do not offer any proof for any other introduction of the submarine Hg into the marine food chain.

Coastal submarine hydrothermal activity off northern Baja California

International Nuclear Information System (INIS)

Vidal, V.M.V.; Vidal, F.V.; Isaacs, J.D.; Young, D.R.

1978-01-01

In situ observations of submarine hydrothermal activity have been conducted in Punta Banda. Baja Califronia, Mexico, approximately 400 m from the coast and at a seawater depth of 30 m. The hydrothermal activity occurs within the Agua Blanca Fault, a major transverse structure of Northern Baja California. Hot springwater samples have been collected and analyzed. Marked differences exist between the submarine hot springwater, local land hot springwaters, groundwater, and local seawater. SiO 2 , HCO 3 , Ca, K, Li, B, Ba, Rb, Fe, Mn, As, and Zn are enriched in the submarine hot springwater, while Cl, Na, So 4 2 , Mg, Cu, Ni, Cd, Cr, and perhaps Pb are depleted in relation to average and local seawater values. Very high temperatures, at the hydrothermal vents, have been recorded (102 0 C at 4-atm pressure). Visible gaseous emanations rich in CH 4 and N 2 coexist with the hydrothermal solutions. Metalliferous deposits, pyrite, have been encountered with high concentrations of Fe, S, Si, Al, Mn, Ca, and the volatile elements As, Hg, Sb, and Tl, X ray dispersive spectrometry (1500-ppm detection limit). X ray diffraction, and scanning electron microscopy of the isolated metalliferous precipitates indicate that the principal products of precipitation are pyrite and gypsum accompanied by minor amounts of amorphous material containing Si and Al. Chemical analyses and XRD of the reference control rocks of the locality (volcanics) versus the hydrothermally altered rocks indicate that high-temperature and high-pressure water-rock interactions can in part explain the water chemistry characteristics of the submarine hydrothermal waters. Their long residence time, the occurrence of an extensive marine sedimentary formation, their association with CH 4 and their similarities with connate waters of oil and gas fields suggest that another component of their genesis could be in cation exchange reactions within deeply buried sediments of marine origin

Development of SPEEDI-MP and its application to a hypothetical accident of a nuclear submarine in the Japan Sea

International Nuclear Information System (INIS)

Kobayashi, Takuya; Nagai, Haruyasu; Chino, Masamichi; Togawa, Orihiko

2004-01-01

A software system SPEEDI-MP is being developed to resolve the environmental problems by simulating the behavior of pollutants in the atmospheric, oceanic and terrestrial environment. Verification of oceanic dispersion prediction codes on the system was carried out to assess the migration behavior of the released 241 Am from a hypothetically sunken nuclear submarine in the Japan Sea. (author)

In-service inspection of the vessels of nuclear submarine reactors

International Nuclear Information System (INIS)

Saglio, R.; Mercier L'Abbe, G.

1977-02-01

Description is given of a machine of automatic inspection of the reactor vessels of nuclear submarines, that was developed by the French Atomic Energy Commission (CEA). A focused ultrasound testing method is used. The equipment such described meets the safety requirements prescribed for the primary circuits of nuclear submarine boiler plants. The sensitivity and resolution power of the apparatus allow such high precision to be obtained as rupture mechanics gains a credibility that could not have been obtained with using conventional apparatus [fr

Exercise Aboard Attack Submarines: Rationale and New Options

National Research Council Canada - National Science Library

Watenpaugh, Donald

2004-01-01

.... However, most submariners do not exercise during deployment for a variety of reasons, including lack of space, time limitations, equipment limitations, lack of entertainment or recreational value...

Operating Below Crush Depth: The Formation, Evolution, and Collapse of the Imperial Japanese Navy Submarine Force in World War II

Science.gov (United States)

2011-06-10

Subamrine, Medium) LCDR Lieutenant Commander LT Lieutenant NM Nautical Mile RADM Rear Admiral ST Sen- Taka (Submarine, High Speed) STo Sen-Toku...Special Submarine) STS Sen- Taka -Sho (Submarine, High Speed(Victory)) USS United States Ship VADM Vice Admiral 1 CHAPTER 1 INTRODUCTION On...Kirai-Sen meaning Mine-Layer, KT for Kai-Toku-Chu meaning Medium, Special Submarine, ST for Sen- Taka meaning Submarine, High speed, STo for Sen Toku

Submarine Volcanic Eruptions and Potential Analogs for Venus

Science.gov (United States)

Wilson, L.; Mouginismark, P. J.; Fryer, P.; Gaddis, L. R.

1985-01-01

As part of an analysis program to better understand the diversity of volcanic processes on the terrestrial planets, an investigation of the volcanic landforms which exist on the Earth's ocean floor was initiated. In part, this analysis is focused toward gaining a better understanding of submarine volcanic landforms in their own right, but also it is hoped that these features may show similarities to volcanic landforms on Venus, due to the high ambient water (Earth) and atmospheric (Venus) pressures. A series of numerical modelling experiments was performed to investigate the relative importance of such attributes as water pressure and temperature on the eruption process, and to determine the rate of cooling and emplacement of lava flows in the submarine environment. Investigations to date show that the confining water pressure and the buoyancy effects of the surrounding water significantly affect the styles of volcanism on the ocean floor. In the case of Venusian volcanism, confining pressures will not be as great as that found at the ocean's abyssal plains, but nevertheless the general trend toward reducing magma vesiculation will hold true for Venus as well as the ocean floor. Furthermore, other analogs may also be found between submarine volcanism and Venusian activity.

The sinking of the Soviet Mike class nuclear powered submarine

International Nuclear Information System (INIS)

1989-01-01

The purpose of this preliminary study is to assess the quantities of the longer-lived or persistent radioactive materials, or source terms, that have been lost at sea with the sinking of the Soviet MIKE class submarine off Bear Island on 7 April 1989. The report arrives at an assessment of the amount of radioactivity and compares this to the quantities of radioactive materials dumped by the UK from 1953 to 1982 at which time sea dumping of radioactive wastes was suspended by international resolve. This comparison can be used to assess the relative significance of the sinking of this submarine. The study does not extrapolate the estimated radioactive source terms to an environmental or radiological significance of the sinking, although it is concluded that unless the submarine is recovered intact from the ocean floor, the by far greater part of the radioactive materials on board will disperse to the marine environment at some future time, if they are not doing so already. (author)

Coastal submarine springs in Lebanon and Syria: Geological, geochemical, and radio-isotopic study

International Nuclear Information System (INIS)

Al-Charideh, A.

2004-10-01

The coastal karst aquifer system (upper Cretaceous) and the submarine springs in the Syrian coast have been studies using chemical and isotopic methods in order to determine the hydraulic connections between the groundwater and the submarine springs. Results show that the groundwater and submarine springs are having the same slope on the σ 18 O/σ 2 H plot indicate the same hydrological origin for both. In addition this relation is very close to the local meteoric water line (LMWL) reflecting a rapid infiltration of rainfall to recharge coastal aquifer. The calculated percentage of freshwater in the two locations (Bassieh and Tartous) range from 20 to 96%. The estimation rate of the permanent submarine springs (BS1, BS2 and TS2, TS3) is 11m 3 /s or 350 million m 3 /y. The maximum residence time of the groundwater in the Cenomanian/Turonian aquifer was estimated at around 8 years, using the piston-flow model.(author)

Losses in armoured three-phase submarine cables

DEFF Research Database (Denmark)

Ebdrup, Thomas; Silva, Filipe Miguel Faria da; Bak, Claus Leth

2014-01-01

The number of offshore wind farms will keep increasing in the future as a part of the shift towards a CO2 free energy production. The energy harvested from the wind farm must be brought to shore, which is often done by using a three-phase armoured submarine power cable. The use of an armour...... increases the losses in armoured cables compared to unarmoured cables. In this paper a thorough state of the art analysis is conducted on armour losses in three-phase armoured submarine power cables. The analysis shows that the IEC 60287-1-1 standard overestimates the armour losses which lead...... to the installation of cables with excessive phase conductor cross section. This paper also presents an example of the potential economic benefits of having a better knowledge of the losses introduced by the armour....

Submarine Groundwater Discharge in the Coastal Zone

Science.gov (United States)

Bakti, Hendra

2018-02-01

Indonesia is one of the archipelagic countries that has the longest coastline in the world. Because it is located in the tropics, in general it has a very high rainfall. Each island has a different morphology which is composed of a variety of rocks with different hydrogeological properties. This natural condition allows for the presence of groundwater in different amount in each island. The difference in groundwater hydraulics gradients in aquifer continuous to the sea has triggered the discharge of groundwater to offshore known as submarine groundwater discharge (SGD). Its presence can be as seepage or submarine springs with components derived from land and sea and a mixture between them. The understanding of SGD phenomenon is very important because it can be useful as a source of clean water in coastal areas, affecting marine health, and improving marine environment.

The characters of emergency rescue and the measures to prevent accidents for nuclear-powered submarine

International Nuclear Information System (INIS)

Wang Yuexing

1999-01-01

The characteristics of emergency rescue and the measures for preventing and decreasing accidents in nuclear-powered submarine have been presented. The breakdown of equipment and human factors are the main reasons which lead to accidents. Four preventive measures are suggested: enhancing capabilities to take precautions against fire, seriously controlling the environmental factors which affect the health of the submariners, reinforcing the constitutions of the submariners, and working out emergency planning against serious accidents in advance

The timing of sediment transport down Monterey Submarine Canyon, offshore California

DEFF Research Database (Denmark)

Stevens, Thomas; Paull, C.K.; Ussler, W., III

2014-01-01

luminescence (OSL) ages of quartz sand deposits and accelerator mass spectrometry 14C ages measured on benthic foraminifera to examine the timing of sediment transport through the axial channel of Monterey Submarine Canyon and Fan, offshore California. The OSL ages date the timing of sediment entry...... dates with water depth provides evidence of mixing and temporary storage of sediment as it moves through the canyon system. The ages also indicate that the frequency of sediment transport events decreases with distance down the canyon channel system. The amalgamated sands near the canyon head yield OSL......While submarine canyons are the major conduits through which sediments are transported from the continents out into the deep sea, the time it takes for sediment to pass down through a submarine canyon system is poorly constrained. Here we report on the first study to couple optically stimulated...

NDT in submarines construction-HY 80

International Nuclear Information System (INIS)

Russo, C.A.; Talmadge, J.

1988-01-01

In submarines construction, provided that metallurgic characteristics have been established, the NDT methods and equipments as well as the application ways should be taken into account. It is then fundamental purpose of this work to emphasize all that coming from conventional context in the field of use of already known nondestructive techniques

Groundwater flow in a coastal peatland and its influence on submarine groundwater discharge

Science.gov (United States)

Ptak, T.; Ibenthal, M.; Janssen, M.; Massmann, G.; Lenartz, B.

2017-12-01

Coastal peatlands are characterized by intense interactions between land and sea, comprising both a submarine discharge of fresh groundwater and inundations of the peatland with seawater. Nutrients and salts can influence the biogeochemical processes both in the shallow marine sediments and in the peatland. The determination of flow direction and quantity of groundwater flow are therefore elementary. Submarine groundwater discharge (SGD) has been reported from several locations in the Baltic. The objective of this study is to quantify the exchange of fresh and brackish water across the shoreline in a coastal peatland in Northeastern Germany, and to assess the influence of a peat layer extending into the Baltic Sea. Below the peatland, a shallow fine sand aquifer differs in depth and is limited downwards by glacial till. Water level and electrical conductivity (EC) are permanently measured in different depths at eight locations in the peatland. First results indicate a general groundwater flow direction towards the sea. Electrical conductivity measurements suggest different permeabilities within the peat layer, depending on its thickness and degradation. Near the beach, EC fluctuates partially during storm events due to seawater intrusion and reverse discharge afterwards. The groundwater flow will be verified with a 3D model considering varying thicknesses of the aquifer. Permanent water level and electrical conductivity readings, meteorological data and hydraulic conductivity from slug tests and grain size analysis are the base for the calibration of the numerical model.

Subjective Symptomology and Postural Control During Simulation of a Survival Environmemt Aboard a Disabled Submarine

National Research Council Canada - National Science Library

Cymerman, Allen

2000-01-01

Subjective symptoms and postural control were assessed in 7 submariners during 5 days exposure to a simulated disabled submarine environment (DISSUB) (4C, 2.5% carbon dioxide, 16.75% oxygen, 85% humidity...

Collection of Arctic Ocean Data from US Navy Submarines on the New SCICEX Program

Science.gov (United States)

Smethie, W. M.; Sambrotto, R.; Boyd, T.; Richter-Menge, J.; Corbett, J.

2011-12-01

The SCICEX submarine Arctic science program originated in the 1990s when six dedicated science cruises were conducted in the Arctic Ocean aboard US Navy Sturgeon class submarines. After the cold war era Sturgeon class submarines were retired, several Science Accommodation cruises, for which a few days for scientific measurements were added to planned submarine transits through the Arctic Ocean, were carried out when opportunities arose. Renewed interest in conducting further Science Accommodation cruises on a regular basis to better document and understand how the Arctic Ocean responds to climate change resulted in publication of a scientific plan in 2010 (http://www.arctic.gov/publications/scicex_plan.pdf). In the spring of 2011 testing of data collection and water sampling methods aboard newer Virginia and Seawolf class submarines on transit from a Navy ice camp in the Beaufort Sea, was conducted in order to develop protocols and evaluate techniques. Ice draft measurements were also taken in the vicinity of the ice camp and near the North Pole to evaluate new data collection systems. This evaluation will include a comparison of the ice draft data with a comprehensive set of in situ ice thickness measurements taken near the ice camp. Under-ice submarine-launched eXpendable Condutivity Temperature Depth (XCTD) probes were deployed from the USS Connecticut (SSN-22), a Seawolf class submarine, and the resulting profiles compared to CTD casts from the APLIS ice station and historical profiles. Water samples were collected through the hull for measurements of tritium, helium isotopes, oxygen isotopes, chlorofluorocarbons, sulfur hexafluoride, nutrients, dissolved organic carbon, bacterioplankton, phytoplankton and particulates levels. These samples were returned to Lamont-Doherty Earth Observatory and were in the process of being measured at the time this abstract was written. Measurements completed at this time indicate good samples can be collected for CFC-12

German Submarine Offensives and South African Countermeasures

African Journals Online (AJOL)

Evert

Scientia Militaria vol 44, no 1, 2016, pp 168-189. doi: 10.5787/44-1-1166 ..... report the presence of a body of German submarines moving south towards Cape Town. Despite ...... London: Arms and Armour Press, 1989, 100–101; Keegan op.

A Helicopter submarine Search Game

Science.gov (United States)

1988-09-01

Figure 3. Graphical representation of Baston and Bostock ................. 10 Figure 4. Dips and Speed Circle...dimen.ional helicopter submarine gaines studied by Meinardi [Ref. 7] and more recently by Baston and Bostock [Ref. 8]. Meinardi solves a discr,-te form of...the game while Baston and Bostock solve the continuous case. Bes.ides Danskin’s game, not much work has been done on the two dimensional case except

BinCat: a Catalog of Nearby Binary Stars with Tools for Calculating Light-Leakage for Direct Imaging Missions

Science.gov (United States)

Holte, Elias Peter; Sirbu, Dan; Belikov, Ruslan

2018-01-01

Binary stars have been largely left out of direct imaging surveys for exoplanets, specifically for earth-sized planets in their star's habitable zone. Utilizing new direct imaging techniques brings us closer to being able to detect earth-like exoplanets around binary stars. In preparation for the upcoming WFIRST mission and other direct imaging-capable missions (HabEx, LUVIOR) it is important to understand the expected science yield resulting from the implementation of these imaging techniques. BinCat is a catalog of binary systems within 30 parsecs to be used as a target list for future direct imaging missions. There is a non-static component along with BinCat that allows researchers to predict the expected light-leakage between a binary component and its off-axis companion (a value critical to the aforementioned techniques) at any epoch. This is accomplished by using orbital elements from the Sixth Orbital Catalog to model the orbits of the binaries. The software was validated against the historical data used to generate the orbital parameters. When orbital information is unknown or the binaries are purely optical the proper motion of the pair taken from the Washington Double Star catalog is integrated in time to estimate expected light-leakage.

Decompression illness in goats following simulated submarine escape: 1993-2006.

Science.gov (United States)

Seddon, F M; Thacker, J C; Fisher, A S; Jurd, K M; White, M G; Loveman, G A M

2014-01-01

The United Kingdom Ministry of Defence commissioned work to define the relationship between the internal pressure of a distressed submarine (DISSUB), the depth from which escape is made and the risk of decompression illness (DCI). The program of work used an animal model (goat) to define these risks and this paper reports the incidence and type of DCI observed. A total of 748 pressure exposures comprising saturation only, escape only or saturation followed by escape were conducted in the submarine escape simulator between 1993 and 2006. The DCI following saturation exposures was predominantly limb pain, whereas following escape exposures the DCI predominantly involved the central nervous system and was fast in onset. There was no strong relationship between the risk of DCI and the range of escape depths investigated. The risk of DCI incurred from escape following saturation was greater than that obtained by combining the risks for the independent saturation only, and escape only, exposures. The output from this program of work has led to improved advice on the safety of submarine escape.

Biological life support systems for a Mars mission planetary base: Problems and prospects

Science.gov (United States)

Tikhomirov, A. A.; Ushakova, S. A.; Kovaleva, N. P.; Lamaze, B.; Lobo, M.; Lasseur, Ch.

The study develops approaches to designing biological life support systems for the Mars mission - for the flight conditions and for a planetary base - using experience of the Institute of Biophysics of the Siberian Branch of the Russian Academy of Sciences (IBP SB RAS) with the Bios-3 system and ESA's experience with the MELISSA program. Variants of a BLSS based on using Chlorella and/or Spirulina and higher plants for the flight period of the Mars mission are analyzed. It is proposed constructing a BLSS with a closed-loop material cycle for gas and water and for part of human waste. A higher-plant-based BLSS with the mass exchange loop closed to various degrees is proposed for a Mars planetary base. Various versions of BLSS configuration and degree of closure of mass exchange are considered, depending on the duration of the Mars mission, the diet of the crew, and some other conditions. Special consideration is given to problems of reliability and sustainability of material cycling in BLSS, which are related to production of additional oxygen inside the system. Technologies of constructing BLSS of various configurations are proposed and substantiated. Reasons are given for using physicochemical methods in BLSS as secondary tools both during the flight and the stay on Mars.

A "feasible direction" search for Lineal Programming problem solving

Directory of Open Access Journals (Sweden)

Jaime U Malpica Angarita

2003-07-01

Full Text Available The study presents an approach to solve linear programming problems with no artificial variables. A primal linear minimization problem is standard form and its associated dual linear maximization problem are used. Initially, the dual (or a partial dual program is solved by a "feasible direction" search, where the Karush-Kuhn-Tucker conditions help to verify its optimality and then its feasibility. The "feasible direction" search exploits the characteristics of the convex polyhedron (or prototype formed by the dual program constraints to find a starting point and then follows line segments, whose directions are found in afine subspaces defined by boundary hyperplanes of polyhedral faces, to find next points up to the (an optimal one. Them, the remaining dual constraints not satisfaced at that optimal dual point, if there are any, are handled as nonbasic variables of the primal program, which is to be solved by such "feasible direction" search.

Alteration of submarine volcanic rocks in oxygenated Archean oceans

Science.gov (United States)

Ohmoto, H.; Bevacqua, D.; Watanabe, Y.

2009-12-01

Most submarine volcanic rocks, including basalts in diverging plate boundaries and andesites/dacites in converging plate boundaries, have been altered by low-temperature seawater and/or hydrothermal fluids (up to ~400°C) under deep oceans; the hydrothermal fluids evolved from shallow/deep circulations of seawater through the underlying hot igneous rocks. Volcanogenic massive sulfide deposits (VMSDs) and banded iron formations (BIFs) were formed by mixing of submarine hydrothermal fluids with local seawater. Therefore, the behaviors of various elements, especially of redox-sensitive elements, in altered submarine volcanic rocks, VMSDs and BIFs can be used to decipher the chemical evolution of the oceans and atmosphere. We have investigated the mineralogy and geochemistry of >500 samples of basalts from a 260m-long drill core section of Hole #1 of the Archean Biosphere Drilling Project (ABDP #1) in the Pilbara Craton, Western Australia. The core section is comprised of ~160 m thick Marble Bar Chert/Jasper Unit (3.46 Ga) and underlying, inter-bedded, and overlying submarine basalts. Losses/gains of 65 elements were quantitatively evaluated on the basis of their concentration ratios against the least mobile elements (Ti, Zr and Nb). We have recognized that mineralogical and geochemical characteristics of many of these samples are essentially the same as those of hydrothermally-altered modern submarine basalts and also those of altered volcanic rocks that underlie Phanerozoic VMSDs. The similarities include, but are not restricted to: (1) the alteration mineralogy (chlorite ± sericite ± pyrophyllite ± carbonates ± hematite ± pyrite ± rutile); (2) the characteristics of whole-rock δ18O and δ34S values; (3) the ranges of depletion and enrichment of Si, Al, Mg, Ca, K, Na, Fe, Mn, and P; (4) the enrichment of Ba (as sulfate); (5) the increases in Fe3+/Fe2+ ratios; (6) the enrichment of U; (7) the depletion of Cr; and (8) the negative Ce anomalies. Literature data

Sun glitter imaging analysis of submarine sand waves in HJ-1A/B satellite CCD images

Science.gov (United States)

Zhang, Huaguo; He, Xiekai; Yang, Kang; Fu, Bin; Guan, Weibing

2014-11-01

Submarine sand waves are a widespread bed-form in tidal environment. Submarine sand waves induce current convergence and divergence that affect sea surface roughness thus become visible in sun glitter images. These sun glitter images have been employed for mapping sand wave topography. However, there are lots of effect factors in sun glitter imaging of the submarine sand waves, such as the imaging geometry and dynamic environment condition. In this paper, several sun glitter images from HJ-1A/B in the Taiwan Banks are selected. These satellite sun glitter images are used to discuss sun glitter imaging characteristics in different sensor parameters and dynamic environment condition. To interpret the imaging characteristics, calculating the sun glitter radiance and analyzing its spatial characteristics of the sand wave in different images is the best way. In this study, a simulated model based on sun glitter radiation transmission is adopted to certify the imaging analysis in further. Some results are drawn based on the study. Firstly, the sun glitter radiation is mainly determined by sensor view angle. Second, the current is another key factor for the sun glitter. The opposite current direction will cause exchanging of bright stripes and dark stripes. Third, brightness reversal would happen at the critical angle. Therefore, when using sun glitter image to obtain depth inversion, one is advised to take advantage of image properties of sand waves and to pay attention to key dynamic environment condition and brightness reversal.

Global land–ocean linkage: direct inputs of nitrogen to coastal waters via submarine groundwater discharge

International Nuclear Information System (INIS)

Beusen, A H W; Slomp, C P; Bouwman, A F

2013-01-01

The role of submarine groundwater discharge (SGD), the leakage of groundwater from aquifers into coastal waters, in coastal eutrophication has been demonstrated mostly for the North American and European coastlines, but poorly quantified in other regions. Here, we present the first spatially explicit global estimates of N inputs via SGD to coastal waters and show that it has increased from about 1.0 to 1.4 Tg of nitrate (NO 3 -N) per year over the second half of the 20th century. Since this increase is not accompanied by an equivalent increase of groundwater phosphorus (P) and silicon (Si), SGD transport of nitrate is an important factor for the development of harmful algal blooms in coastal waters. Groundwater fluxes of N are linked to areas with high runoff and intensive anthropogenic activity on land, with Southeast Asia, parts of North and Central America, and Europe being hot spots. (letter)

Science Parametrics for Missions to Search for Earth-like Exoplanets by Direct Imaging

Science.gov (United States)

Brown, Robert A.

2015-01-01

We use Nt , the number of exoplanets observed in time t, as a science metric to study direct-search missions like Terrestrial Planet Finder. In our model, N has 27 parameters, divided into three categories: 2 astronomical, 7 instrumental, and 18 science-operational. For various "27-vectors" of those parameters chosen to explore parameter space, we compute design reference missions to estimate Nt . Our treatment includes the recovery of completeness c after a search observation, for revisits, solar and antisolar avoidance, observational overhead, and follow-on spectroscopy. Our baseline 27-vector has aperture D = 16 m, inner working angle IWA = 0.039'', mission time t = 0-5 yr, occurrence probability for Earth-like exoplanets η = 0.2, and typical values for the remaining 23 parameters. For the baseline case, a typical five-year design reference mission has an input catalog of ~4700 stars with nonzero completeness, ~1300 unique stars observed in ~2600 observations, of which ~1300 are revisits, and it produces N 1 ~ 50 exoplanets after one year and N 5 ~ 130 after five years. We explore offsets from the baseline for 10 parameters. We find that N depends strongly on IWA and only weakly on D. It also depends only weakly on zodiacal light for Z end-to-end efficiency for h > 0.2, and scattered starlight for ζ revisits, solar and antisolar avoidance, and follow-on spectroscopy are all important factors in estimating N.

A Modified Alternating Direction Method for Variational Inequality Problems

International Nuclear Information System (INIS)

Han, D.

2002-01-01

The alternating direction method is an attractive method for solving large-scale variational inequality problems whenever the subproblems can be solved efficiently. However, the subproblems are still variational inequality problems, which are as structurally difficult to solve as the original one. To overcome this disadvantage, in this paper we propose a new alternating direction method for solving a class of nonlinear monotone variational inequality problems. In each iteration the method just makes an orthogonal projection to a simple set and some function evaluations. We report some preliminary computational results to illustrate the efficiency of the method

[Effects of submarine topography and water depth on distribution of pelagic fish community in minnan-taiwan bank fishing ground].

Science.gov (United States)

Fang, Shuimei; Yang, Shengyun; Zhang, Chengmao; Zhu, Jinfu

2002-11-01

According to the fishing record of the light-seine information vessel in Minnan-Taiwan bank ground during 1989 to 1999, the effects of submarine topography and water depth on distribution of pelagic fish community in Minnan-Taiwan bank fishing ground was studied. The results showed that the pelagic fish distributed concentratively, while the submarine topography and water depth varied widely, but in different fishing regions, the distribution of pelagic fishes was uneven. The distribution of fishing yield increased from north to south, and closed up from sides of the bank to south or north in the regions. Pelagic fish distributed mainly in mixed water in the southern Taiwan Strait, and in warm water in the Taiwan Strait. The central fishing grounds were at high salt regions. Close gathering regions of pelagic fish or central fishing ground would be varied with the seasonal variation of mixed water in the southern Taiwan Strait and warm water in the Taiwan Strait. Central fishing ground was not only related to submarine topography and water depth, but also related to wind direction, wind-power and various water systems. In the fishing ground, the gathering depth of pelagic fish was 30-60 m in spring and summer, and 40-80 m in autumn and winter.

Origin of Abiotic Methane in Submarine Hydrothermal Systems

Science.gov (United States)

Seewald, J. S.; German, C. R.; Grozeva, N. G.; Klein, F.; McDermott, J. M.; Ono, S.; Reeves, E. P.; Wang, D. T.

2018-05-01

Results of recent investigations into the chemical and isotopic composition of actively venting submarine hydrothermal fluids and volatile species trapped in fluid inclusions will be discussed in the context of processes responsible for abiotic CH4 formation.

Problem of data privacy protection in direct marketing

Directory of Open Access Journals (Sweden)

Markov Jasmina

2011-01-01

Full Text Available The dynamism of modern business conditions, as well as increasing competition, call for companies to change their usual ways of doing business and communicating with consumers. Therefore, today's direct marketing industry is experiencing explosive growth, as more and more companies include these activities in their communication mix. Many companies benefit from the development and usage of direct marketing, but at the same time, its growing usage led to numerous problems for companies as well as for the consumers. Direct marketing, advanced information technologies and Internet, on whose use it is more and more based, caused a number of legal and ethical questions without precedent. One of the issues that is making consumers more and more worried is concerning the privacy of their personal data and information which is being collected by a large number of companies. In addition, consumers are often not aware of this data collecting, which is adding even more gravity to this problem. The remainder of this paper will point to the necessity and great importance of careful and responsible use of consumer's personal data by direct marketers, with the aim of build long-term partnership relationships between the two. In addition, special attention will be paid to major problems that consumers face today in the field of data protection, as well as to the efforts committed in order to bring these problems to a minimum by getting consumers more involved in making decisions about usage of their personal data and information.

The sedimentary record of submarine channel morphodynamics

NARCIS (Netherlands)

de Leeuw, J.

2017-01-01

Submarine channels are ubiquitous on the ocean floor and are considered to be the equivalent of rivers on land. These channels are created by turbidity currents, which originate from the continental margins and which can transport sediment for thousands of kilometres into the oceans. The aim of this

Experience of NS disposal at the Enterprise ''Zvezdochka'', in Severodvinsk. Problems of ecological safety

International Nuclear Information System (INIS)

Kozlov, Yuri

1999-01-01

According to this presentation, decommissioning and disposal of nuclear submarines is a problem of great concern in Russia. So far more than 150 nuclear submarines have been removed from the Fleet and will be disposed of. Future disposals were not taken into consideration when the shipyards were constructed. Nuclear vessels with loaded cores stay afloat waiting for their turn to be disposed of, often with damaged safety assurance systems and a potential for causing major ecological catastrophes. The presentation deals briefly with some international programmes in progress at Nerpa in Murmansk, Zvezda in Primorye and Zvezdochka in Arkhangelsk and then discusses in more detail the experience of disposal at the Zvezdochka, which under the Start-2 agreement is defined as one of the enterprises dealing with the disposal of strategic nuclear submarines. There they have the qualified staff and the equipment needed. Spent nuclear fuel unloading and removal is the most acute problem

Radon as an indicator of submarine groundwater discharge in coastal regions

International Nuclear Information System (INIS)

Jacob, Noble; Shivanna, K.; Suresh Babu, D.S.

2009-01-01

This article reviews the various available methodologies to estimate submarine groundwater discharge (SGD) and demonstrates the utility of radon with a case study. An attempt has been made to identify the existence of submarine groundwater discharge (SGD) and semi-quantitatively estimate its rate in the coastal area of Vizhinjam, Thiruvananthapuram, Kerala. Natural 222 Rn (half-life = 3.8 days) was used as a tracer of SGD because of its conservative nature, short half-life, easiness in measurement and high abundance in groundwater. As in situ radon ( 222 Rn) monitoring study conducted in this region indicated comparatively higher 222 Rn activities (average 14.1±1.7 Bq/m 3 ) in the coastal waters revealing significant submarine groundwater discharge. The SGD may be a combination of fresh groundwater and recirculated seawater that is controlled by the hydraulic gradient in the adjacent aquifer and varying tidal conditions in the coastal waters. Using a transient 222 Rn mass balance model for the coastal waters, SGD rates were computed and the average value was found to be 10.9±6.1 cm/day. These estimates are comparable with those reported in the literature. In general, identification and estimation of submarine groundwater discharge is important in the Indian context because of the possibility of large amounts of groundwater loss through its long coastline, that can be judiciously exploited to cater to the present water requirements for drinking and irrigation purposes. (author)

Artificial Neural Network Based Mission Planning Mechanism for Spacecraft

Science.gov (United States)

Li, Zhaoyu; Xu, Rui; Cui, Pingyuan; Zhu, Shengying

2018-04-01

The ability to plan and react fast in dynamic space environments is central to intelligent behavior of spacecraft. For space and robotic applications, many planners have been used. But it is difficult to encode the domain knowledge and directly use existing techniques such as heuristic to improve the performance of the application systems. Therefore, regarding planning as an advanced control problem, this paper first proposes an autonomous mission planning and action selection mechanism through a multiple layer perceptron neural network approach to select actions in planning process and improve efficiency. To prove the availability and effectiveness, we use autonomous mission planning problems of the spacecraft, which is a sophisticated system with complex subsystems and constraints as an example. Simulation results have shown that artificial neural networks (ANNs) are usable for planning problems. Compared with the existing planning method in EUROPA, the mechanism using ANNs is more efficient and can guarantee stable performance. Therefore, the mechanism proposed in this paper is more suitable for planning problems of spacecraft that require real time and stability.

Lava delta deformation as a proxy for submarine slope instability

Science.gov (United States)

Di Traglia, Federico; Nolesini, Teresa; Solari, Lorenzo; Ciampalini, Andrea; Frodella, William; Steri, Damiano; Allotta, Benedetto; Rindi, Andrea; Marini, Lorenzo; Monni, Niccolò; Galardi, Emanuele; Casagli, Nicola

2018-04-01

The instability of lava deltas is a recurrent phenomenon affecting volcanic islands, which can potentially cause secondary events such as littoral explosions (due to interactions between hot lava and seawater) and tsunamis. It has been shown that Interferometric Synthetic Aperture Radar (InSAR) is a powerful technique to forecast the collapse of newly emplaced lava deltas. This work goes further, demonstrating that the monitoring of lava deltas is a successful strategy by which to observe the long-term deformation of subaerial-submarine landslide systems on unstable volcanic flanks. In this paper, displacement measurements derived from Synthetic Aperture Radar (SAR) imagery were used to detect lava delta instability at Stromboli volcano (Italy). Recent flank eruptions (2002-2003, 2007 and 2014) affected the Sciara del Fuoco (SdF) depression, created a "stacked" lava delta, which overlies a pre-existing scar produced by a submarine-subaerial tsunamigenic landslide that occurred on 30 December 2002. Space-borne X-band COSMO-SkyMED (CSK) and C-band SENTINEL-1A (SNT) SAR data collected between February 2010 and October 2016 were processed using the SqueeSAR algorithm. The obtained ground displacement maps revealed the differential ground motion of the lava delta in both CSK and SNT datasets, identifying a stable area (characterized by less than 2 mm/y in both datasets) within the northern sector of the SdF and an unstable area (characterized by velocity fields on the order of 30 mm/y and 160 mm/y in the CSK and SNT datasets, respectively) in the central sector of the SdF. The slope stability of the offshore part of the SdF, as reconstructed based on a recently performed multibeam bathymetric survey, was evaluated using a 3D Limit Equilibrium Method (LEM). In all the simulations, Factor of Safety (F) values between 0.9 and 1.1 always characterized the submarine slope between the coastline and -250 m a.s.l. The critical surfaces for all the search volumes corresponded to

Size distributions and failure initiation of submarine and subaerial landslides

Science.gov (United States)

ten Brink, Uri S.; Barkan, R.; Andrews, B.D.; Chaytor, J.D.

2009-01-01

Landslides are often viewed together with other natural hazards, such as earthquakes and fires, as phenomena whose size distribution obeys an inverse power law. Inverse power law distributions are the result of additive avalanche processes, in which the final size cannot be predicted at the onset of the disturbance. Volume and area distributions of submarine landslides along the U.S. Atlantic continental slope follow a lognormal distribution and not an inverse power law. Using Monte Carlo simulations, we generated area distributions of submarine landslides that show a characteristic size and with few smaller and larger areas, which can be described well by a lognormal distribution. To generate these distributions we assumed that the area of slope failure depends on earthquake magnitude, i.e., that failure occurs simultaneously over the area affected by horizontal ground shaking, and does not cascade from nucleating points. Furthermore, the downslope movement of displaced sediments does not entrain significant amounts of additional material. Our simulations fit well the area distribution of landslide sources along the Atlantic continental margin, if we assume that the slope has been subjected to earthquakes of magnitude ??? 6.3. Regions of submarine landslides, whose area distributions obey inverse power laws, may be controlled by different generation mechanisms, such as the gradual development of fractures in the headwalls of cliffs. The observation of a large number of small subaerial landslides being triggered by a single earthquake is also compatible with the hypothesis that failure occurs simultaneously in many locations within the area affected by ground shaking. Unlike submarine landslides, which are found on large uniformly-dipping slopes, a single large landslide scarp cannot form on land because of the heterogeneous morphology and short slope distances of tectonically-active subaerial regions. However, for a given earthquake magnitude, the total area

A kuroko-type polymetallic sulfide deposit in a submarine silicic caldera

Science.gov (United States)

Iizasa; Fiske; Ishizuka; Yuasa; Hashimoto; Ishibashi; Naka; Horii; Fujiwara; Imai; Koyama

1999-02-12

Manned submersible studies have delineated a large and actively growing Kuroko-type volcanogenic massive sulfide deposit 400 kilometers south of Tokyo in Myojin Knoll submarine caldera. The sulfide body is located on the caldera floor at a depth of 1210 to 1360 meters, has an area of 400 by 400 by 30 meters, and is notably rich in gold and silver. The discovery of a large Kuroko-type polymetallic sulfide deposit in this arc-front caldera raises the possibility that the numerous unexplored submarine silicic calderas elsewhere might have similar deposits.

Submarine geologic disposal of nuclear waste

International Nuclear Information System (INIS)

Hollister, C.D.; Corliss, B.H.; Anderson, D.R.

1980-01-01

Site suitability characteristics of submarine geological formations for the disposal of radioactive wastes include the distribution coefficient of the host medium, permeability, viscoelastic nature of the sediments, influence of organic material on remobilization, and effects of thermal stress. The submarine geological formation that appears to best satisfy these criteria is abyssal ''red'' clay. Regions in the ocean that have coarse-grained deposits, high or variable thermal conductivity, high organic carbon content, and sediment thickness of less than 50 m are not being considered at this time. The optimum geological environment should be tranquil and have environmental predictability over a minimum of 10 5 years. Site selection activities for the North Atlantic and North Pacific are reviewed and future activities which include international cooperation are discussed. A paleoenvironmental model for Cenozoic sedimentation in the central North Pacific is presented based on studies of a long core from the Mid-Plate Gyre MPG-1 area, and is an example of the type of study that will be carried out in other seabed study areas. The data show that the MPG-1 region has been an area of slow, continuous accumulation during the past 65 million years. (author)

Virtual Reality Training System for a Submarine Command Center

National Research Council Canada - National Science Library

Maxwell, Douglas B

2008-01-01

The invention as disclosed is a system that uses a combined real and virtual display interaction methodology to generate the visual appearance of submarine combat control rooms and allow interaction...

Gender integration on U.S. Navy submarines: views of the first wave

OpenAIRE

Ellis, Krysten J.; Munson, Garold I.

2015-01-01

Approved for public release; distribution is unlimited This project is an ethnographic case study documenting the experiences of the first group of women integrated into the United States Submarine Force. The study seeks to: 1) document the process through which each of the women was selected and became a submariner; 2) identify hindering and supporting issues and concerns (e.g., life-work balance, job-role expectations, and career development); 3) describe the organizational culture and c...

Submarine geology and geomorphology of active Sub-Antarctic volcanoes: Heard and McDonald Islands

Science.gov (United States)

Watson, S. J.; Coffin, M. F.; Whittaker, J. M.; Lucieer, V.; Fox, J. M.; Carey, R.; Arculus, R. J.; Bowie, A. R.; Chase, Z.; Robertson, R.; Martin, T.; Cooke, F.

2016-12-01

Heard and McDonald Islands (HIMI) are World Heritage listed sub-Antarctic active volcanic islands in the Southern Indian Ocean. Built atop the Kerguelen Plateau by Neogene-Quaternary volcanism, HIMI represent subaerial exposures of the second largest submarine Large Igneous Province globally. Onshore, processes influencing island evolution include glaciers, weathering, volcanism, vertical tectonics and mass-wasting (Duncan et al. 2016). Waters surrounding HIMI are largely uncharted, due to their remote location. Hence, the extent to which these same processes shape the submarine environment around HIMI has not been investigated. In early 2016, we conducted marine geophysical and geologic surveys around HIMI aboard RV Investigator (IN2016_V01). Results show that volcanic and sedimentary features prominently trend east-west, likely a result of erosion by the eastward flowing Antarctic Circumpolar Current and tidal currents. However, spatial patterns of submarine volcanism and sediment distribution differ substantially between the islands. >70 sea knolls surround McDonald Island suggesting substantial submarine volcanism. Geophysical data reveals hard volcanic seafloor around McDonald Island, whereas Heard Island is characterised by sedimentary sequences tens of meters or more thick and iceberg scours - indicative of glacial processes. Differences in submarine geomorphology are likely due to the active glaciation of Heard Island and differing rock types (Heard: alkali basalt, McDonald: phonolite), and dominant products (clastics vs. lava). Variations may also reflect different magmatic plumbing systems beneath the two active volcanoes (Heard produces larger volumes of more focused lava, whilst McDonald extrudes smaller volumes of more evolved lavas from multiple vents across the edifice). Using geophysical data, corroborated with new and existing geologic data, we present the first geomorphic map revealing the processes that shape the submarine environment around HIMI.

Multicore fibers for high-capacity submarine transmission systems

DEFF Research Database (Denmark)

Nooruzzaman, Md.; Morioka, Toshio

2018-01-01

Applications of multicore fibers (MCFs) in undersea transmission systems are investigated, and various potential architectures of branching units for MCF-based undersea transmission systems are presented. Some MCF-based submarine network architectures based on the amount of data traffic are also...

Crustal volumes of the continents and of oceanic and continental submarine plateaus

Science.gov (United States)

Schubert, G.; Sandwell, D.

1989-01-01

Using global topographic data and the assumption of Airy isostasy, it is estimated that the crustal volume of the continents is 7182 X 10 to the 6th cu km. The crustal volumes of the oceanic and continental submarine plateaus are calculated at 369 X 10 to the 6th cu km and 242 X 10 to the 6th cu km, respectively. The total continental crustal volume is found to be 7581 X 10 to the 6th cu km, 3.2 percent of which is comprised of continental submarine plateaus on the seafloor. An upper bound on the contintental crust addition rate by the accretion of oceanic plateaus is set at 3.7 cu km/yr. Subduction of continental submarine plateaus with the oceanic lithosphere on a 100 Myr time scale yields an upper bound to the continental crustal subtraction rate of 2.4 cu km/yr.

A submarine landslide source for the devastating 1964 Chenega tsunami, southern Alaska

Science.gov (United States)

Brothers, Daniel; Haeussler, Peter J.; Lee Liberty,; David Finlayson,; Geist, Eric L.; Labay, Keith A.; Michael Byerly,

2016-01-01

During the 1964 Great Alaska earthquake (Mw 9.2), several fjords, straits, and bays throughout southern Alaska experienced significant tsunami runup of localized, but unexplained origin. Dangerous Passage is a glacimarine fjord in western Prince William Sound, which experienced a tsunami that devastated the village of Chenega where 23 of 75 inhabitants were lost – the highest relative loss of any community during the earthquake. Previous studies suggested the source of the devastating tsunami was either from a local submarine landslide of unknown origin or from coseismic tectonic displacement. Here we present new observations from high-resolution multibeam bathymetry and seismic reflection surveys conducted in the waters adjacent to the village of Chenega. The seabed morphology and substrate architecture reveal a large submarine landslide complex in water depths of 120–360 m. Analysis of bathymetric change between 1957 and 2014 indicates the upper 20–50 m (∼0.7 km3) of glacimarine sediment was destabilized and evacuated from the steep face of a submerged moraine and an adjacent ∼21 km2 perched sedimentary basin. Once mobilized, landslide debris poured over the steep, 130 m-high face of a deeper moraine and then blanketed the terminal basin (∼465 m water depth) in 11 ± 5 m of sediment. These results, combined with inverse tsunami travel-time modeling, suggest that earthquake- triggered submarine landslides generated the tsunami that struck the village of Chenega roughly 4 min after shaking began. Unlike other tsunamigenic landslides observed in and around Prince William Sound in 1964, the failures in Dangerous Passage are not linked to an active submarine delta. The requisite environmental conditions needed to generate large submarine landslides in glacimarine fjords around the world may be more common than previously thought. 

Evolution and Submarine Landslide Potential of Monterey Canyon Head, Offshore Central California

Science.gov (United States)

Maier, K. L.; Johnson, S. Y.; Hart, P. E.; Hartwell, S. R.

2016-12-01

Monterey Canyon, offshore central California, incises the shelf from near the shoreline to 30 km seaward where axial water depths approach 2,000 m. It is one of the world's most studied submarine canyons, yet debate continues concerning its age, formation, and associated geologic hazards. To address these issues, the USGS, with partial support from the California Seafloor Mapping Program, collected hundreds of kilometers of high-resolution, mini-sparker, single-channel (2009 and 2011 surveys) and multichannel (2015 survey) seismic-reflection profiles near the canyon head. The seismic data were combined with multibeam bathymetry to generate a geologic map of the proximal canyon, which delineates numerous faults and compound submarine landslide headwall scarps (covering up to 4 km2) along canyon walls. Seismic-reflection data reveal a massive ( 100 km2 lateral extent) paleochannel cut-and-fill complex underlying the proximal canyon. These subsurface cut-and-fill deposits span both sides of the relatively narrow modern canyon head, crop out in canyon walls, and incise into Purisima Formation (late Miocene and Pliocene) bedrock to depths of up to 0.3 s two-way travel time ( 240 m) below the modern shelf. We propose that the paleochannel complex represents previous locations of a migrating canyon head, and attribute its origin to multiple alternating cycles of fluvial and submarine canyon erosion and deposition linked to fluctuating sea levels. Thus, the canyon head imaged in modern bathymetry is a relatively young feature, perhaps forming in the last 20,000 years of sea-level rise. The paleocanyon deposits are significantly less consolidated than bedrock in deeper canyon walls, and therefore, are probably more prone to submarine landsliding. Nearby mapped faults occur within the active, distributed, San Andreas fault system, and earthquake-generated strong ground motions are likely triggers for past and future submarine landslides and potential associated tsunamis.

Experimental Investigation of Effect of the Sail with Leading Edge Fillet on Flow around a Submarine

OpenAIRE

Mohsen Rahmany; Amir Hamzeh Farajollahi; Mojtaba Dehghan Manshadi

2016-01-01

Because of connecting the various appendages of submarine to the main body the vortices have been created that disrupt the flow uniformity and make the undesirable features such as vortex formation to flow. Vortices that have been created due to the connectivity of sail to the body of submarines have a significant impact on non-uniformity of submarine wake at location of the propeller disc. In present research the use of hot wire anemometer has created vertical flow field in back of the two s...

Experimental Insights on Natural Lava-Ice/Snow Interactions and Their Implications for Glaciovolcanic and Submarine Eruptions

Science.gov (United States)

Edwards, B. R.; Karson, J.; Wysocki, R.; Lev, E.; Bindeman, I. N.; Kueppers, U.

2012-12-01

Lava-ice-snow interactions have recently gained global attention through the eruptions of ice-covered volcanoes, particularly from Eyjafjallajokull in south-central Iceland, with dramatic effects on local communities and global air travel. However, as with most submarine eruptions, direct observations of lava-ice/snow interactions are rare. Only a few hundred potentially active volcanoes are presently ice-covered, these volcanoes are generally in remote places, and their associated hazards make close observation and measurements dangerous. Here we report the results of the first large-scale experiments designed to provide new constraints on natural interactions between lava and ice/snow. The experiments comprised controlled effusion of tens of kilograms of melted basalt on top of ice/snow, and provide insights about observations from natural lava-ice-snow interactions including new constraints for: 1) rapid lava advance along the ice-lava interface; 2) rapid downwards melting of lava flows through ice; 3) lava flow exploitation of pre-existing discontinuities to travel laterally beneath and within ice; and 4) formation of abundant limu o Pele and non-explosive vapor transport from the base to the top of the lava flow with minor O isotope exchange. The experiments are consistent with observations from eruptions showing that lava is more efficient at melting ice when emplaced on top of the ice as opposed to beneath the ice, as well as the efficacy of tephra cover for slowing melting. The experimental extrusion rates are as within the range of those for submarine eruptions as well, and reproduce some features seen in submarine eruptions including voluminous production of gas rich cavities within initially anhydrous lavas and limu on lava surfaces. Our initial results raise questions about the possibility of secondary ingestion of water by submarine and glaciovolcanic lava flows, and the origins of apparent primary gas cavities in those flows. Basaltic melt moving down

The X-ray Astronomy Recovery Mission

Science.gov (United States)

Tashiro, M.; Kelley, R.

2017-10-01

On 25 March 2016, the Japanese 6th X-ray astronomical satellite ASTRO-H (Hitomi), launched on February 17, lost communication after a series of mishap in its attitude control system. In response to the mishap the X-ray astronomy community and JAXA analyzed the direct and root cause of the mishap and investigated possibility of a recovery mission with the international collaborator NASA and ESA. Thanks to great effort of scientists, agencies, and governments, the X-ray Astronomy Recovery Mission (XARM) are proposed. The recovery mission is planned to resume high resolution X-ray spectroscopy with imaging realized by Hitomi under the international collaboration in the shortest time possible, simply by focusing one of the main science goals of Hitomi Resolving astrophysical problems by precise high-resolution X-ray spectroscopy'. XARM will carry a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly, and an aligned X-ray CCD camera covering the same energy band and wider field of view, but no hard X-ray or soft gamma-ray instruments are onboard. In this paper, we introduce the science objectives, mission concept, and schedule of XARM.

Tsunami waves generated by submarine landslides of variable volume: analytical solutions for a basin of variable depth

Directory of Open Access Journals (Sweden)

I. Didenkulova

2010-11-01

Full Text Available Tsunami wave generation by submarine landslides of a variable volume in a basin of variable depth is studied within the shallow-water theory. The problem of landslide induced tsunami wave generation and propagation is studied analytically for two specific convex bottom profiles (h ~ x^4/3 and h ~ x⁴. In these cases the basic equations can be reduced to the constant-coefficient wave equation with the forcing determined by the landslide motion. For certain conditions on the landslide characteristics (speed and volume per unit cross-section the wave field can be described explicitly. It is represented by one forced wave propagating with the speed of the landslide and following its offshore direction, and two free waves propagating in opposite directions with the wave celerity. For the case of a near-resonant motion of the landslide along the power bottom profile h ~ x^γ the dynamics of the waves propagating offshore is studied using the asymptotic approach. If the landslide is moving in the fully resonant regime the explicit formula for the amplitude of the wave can be derived. It is demonstrated that generally tsunami wave amplitude varies non-monotonically with distance.

German Submarine Offensives and South African Countermeasures

African Journals Online (AJOL)

Evert

World War, with a number of opportunistic attacks also made by submarines travelling to the Far ..... This time round, however, the strategic importance of the Indian Ocean ... offensive operations in the Indian Ocean between the Gulf of Aden and the ... American seaboards, which ensured that an attack around the coast off ...

First direct observations linking confined supercritical turbidity currents to their depositional architecture and facies characteristics

Science.gov (United States)

Hage, S.; Cartigny, M.; Hughes Clarke, J. E.; Clare, M. A.; Sumner, E.; Hubbard, S. M.; Talling, P.; Lintern, G.; Stacey, C.; Vardy, M. E.; Hunt, J.; Vendettuoli, D.; Yokokawa, M.; Hizzett, J. L.; Vellinga, A. J.; Azpiroz, M.

2017-12-01

Turbidity currents transfer globally significant amounts of sediment via submarine channels from the continental margin to deep submarine fans. Submarine channel inception is thought to result from erosive, supercritical turbidity currents that are common in proximal settings of the marine realm. Recent monitoring of submarine processes have provided the first measurements of supercritical turbidity currents (Hughes Clarke, 2016), demonstrating that they drive the upstream migration of crescentic bedforms in confined submarine channels. Although upstream-migrating bedforms are common in confined channels across the world's oceans, there is considerable debate over the type of deposits that they produce. It is important to understand what types of deposit record these supercritical bedforms to potentially identify them from geological archives. For the first time, we combine direct measurements from supercritical field-scale turbidity currents with the facies and depositional architecture resulting from such flows. We show how the subsurface architecture evolves in a highly active channel at Squamish submarine delta, British Columbia, Canada. Repeated upstream migration of bedforms is found to create two main deposit geometries. First, regular back-stepping beds result from flow deceleration on the slightly-inclined sides of the bedforms. Second, lens-shaped scour fills composed of massive deposits result from erosion of the back-stepping beds by subsequent turbidity currents. We relate our findings to a range of ancient outcrop studies to demonstrate that supercritical flows are common in proximal settings through the geological record. This study provides the first direct observation-based model to identify confined supercritical turbidity currents and their associated upslope-migrating bedforms in the sedimentary record. This is important for correctly identifying the proximal sites of ancient submarine channels that served as past conduits for globally

SCIENCE PARAMETRICS FOR MISSIONS TO SEARCH FOR EARTH-LIKE EXOPLANETS BY DIRECT IMAGING

International Nuclear Information System (INIS)

Brown, Robert A.

2015-01-01

We use N t , the number of exoplanets observed in time t, as a science metric to study direct-search missions like Terrestrial Planet Finder. In our model, N has 27 parameters, divided into three categories: 2 astronomical, 7 instrumental, and 18 science-operational. For various ''27-vectors'' of those parameters chosen to explore parameter space, we compute design reference missions to estimate N t . Our treatment includes the recovery of completeness c after a search observation, for revisits, solar and antisolar avoidance, observational overhead, and follow-on spectroscopy. Our baseline 27-vector has aperture D = 16 m, inner working angle IWA = 0.039'', mission time t = 0-5 yr, occurrence probability for Earth-like exoplanets η = 0.2, and typical values for the remaining 23 parameters. For the baseline case, a typical five-year design reference mission has an input catalog of ∼4700 stars with nonzero completeness, ∼1300 unique stars observed in ∼2600 observations, of which ∼1300 are revisits, and it produces N 1 ∼ 50 exoplanets after one year and N 5 ∼ 130 after five years. We explore offsets from the baseline for 10 parameters. We find that N depends strongly on IWA and only weakly on D. It also depends only weakly on zodiacal light for Z < 50 zodis, end-to-end efficiency for h > 0.2, and scattered starlight for ζ < 10 –10 . We find that observational overheads, completeness recovery and revisits, solar and antisolar avoidance, and follow-on spectroscopy are all important factors in estimating N

MVAC Submarine cable, magnetic fields measurements and analysis

DEFF Research Database (Denmark)

Arentsen, Martin Trolle; Expethit, Adrian; Pedersen, Morten Virklund

2017-01-01

Standard 60287. Researchers believe that the wire armour of three phased submarine cables is the reason for the inaccurate calculations by the standard. Studies show that the magnetic behaviour of these cables are changed due to the wire armour. In order to investigate this hypothesis, this paper intends...... to supply the theoretical research with data from magnetic field measurements on a wire armoured 3-phase submarine cable, together with an investigation of the induced currents in the different cable components. The influence of the physical arrangement of the armour wires on the electric behaviour is also...... investigated, since several researchers believe that the twisting of the armour wires result in zero net induced voltage over one helix length. This is shown to be valid for the tested cable. Finally a replica of the armour has been built with just a single conductor in the centre. This setup was used...

Understanding losses in three core armoured submarine cables

DEFF Research Database (Denmark)

Silva, Filipe Miguel Faria da; Ebdrup, Thomas; Bak, Claus Leth

2016-01-01

. For practical an economical reasons the preferred choice of cable for both the array and the transmission cables are three-core armoured submarine cables. Therefore, it has becoming increasingly important to be able to calculate the ampacity of such cables accurately. At present time, the ampacity of three......-core armoured submarine cables is calculated according to IEC 60287-1-1 [1]. Various measurements conducted both by cable manufacturers and transmission system operators (TSO) have shown that using the cable rating method stated in IEC 60287-1-1 underestimates the cable ampacity [2]-[6]. Furthermore......, measurements conducted within the cable industry have shown that an armoured three core cable has higher losses than equal unarmoured three core cables. It is also suggested that the inaccuracy in the IEC armour’s loss factor (λ2) is the main responsible for the conservatism in the IEC cable rating method...

Submarine Biofouling Control- Chlorination DATS Study at Pearl Harbor

National Research Council Canada - National Science Library

Wegand, John

2001-01-01

The intent of this document is to sumarize the chlorination studies performed at Naval Station, Pearl Harbor in support of biofouling control initiatives for the submarine community, as requested by NAVSEA 92T...

ESR dating of submarine hydrothermal activities using barite in sulfide deposition

Science.gov (United States)

Toyoda, S.; Fujiwara, T.; Ishibashi, J.; Isono, Y.; Uchida, A.; Takamasa, A.; Nakai, S.

2012-12-01

The temporal change of submarine hydrothermal activities has been an important issue in the aspect of the evolution of hydrothermal systems which is related with ore formation (Urabe, 1995) and biological systems sustained by the chemical species arising from hydrothermal activities (Macdonald et al., 1980). Determining the ages of the hydrothermal deposit will provide essential information on such studies. Dating methods using disequilibrium between radioisotopes such as U-Th method (e.g. You and Bickle, 1998), 226}Ra-{210Pb and 228}Ra-{228Th method (e.g. Noguchi et al., 2011) have been applied to date submarine hydrothermal deposits. ESR (electron spin resonance) dating method is commonly applied to fossil teeth, shells, and quartz of Quaternay period where the natural accumulated dose is obtained from the intensities of the ESR signals which are created by natural radiation. The natural dose is divided by the dose rate to the mineral/sample to deduce the age. Okumura et al., (2010) made the first practical application of ESR (electron spin resonance) dating technique to a sample of submarine hydrothermal barite (BaSO4) to obtain preliminary ages, where Kasuya et al. (1991) first pointed out that barite can be used for ESR dating. Knowing that ESR dating of barite is promising, in this paper, we will present how we have investigated each factor that contributes ESR dating of barite in submarine hydrothermal sulfide deposition. (1) The best ESR condition for measuring the SO3- signal in barite is with the microwave power of 1mW and modulation amplitude of 0.1mT. (2) As results of heating experiments, the signal was found to be stable for the dating age range of several thousands. (3) 226Ra replacing Ba in barite is the source of the radiation. The amount of radioactive elements in sulfide mineral surrounding barite is negligible. (4) The external radiation from the sea water is negligible even in the submarine hydrothermal area where the radiation level is much

[Dynamics of functional status of submarine personnel during the pre-deployment period].

Science.gov (United States)

Khankevich, Iu R; Bloshchinskiĭ, I A; Val'skiĭ, A V; Nabokov, N L

2014-09-01

Authors came to conclusions that during the pre-deployment period submarine personnel are stressed out. During this period submarine personnel .usually resupply, conduct maintenance and other monitoring-and-checkout measures, which leads to functional stress. Authors came to conclusion that it is necessary to use simple and easy, but at the same time informative methods for early diagnosis of worsen functional health status. One of these methods is evaluation of indicators of cardiovascular system. This method is a base for functional health status prophylaxis.

Direct and inverse problems of infrared tomography

DEFF Research Database (Denmark)

Sizikov, Valery S.; Evseev, Vadim; Fateev, Alexander

2016-01-01

The problems of infrared tomography-direct (the modeling of measured functions) and inverse (the reconstruction of gaseous medium parameters)-are considered with a laboratory burner flame as an example of an application. The two measurement modes are used: active (ON) with an external IR source...

AUV Mapping and ROV Exploration of Los Frailes Submarine Canyon, Cabo Pulmo National Marine Park, Baja California Sur, Mexico

Science.gov (United States)

Troni, G.; Caress, D. W.; Graves, D.; Thomas, H. J.; Thompson, D.; Barry, J. P.; Aburto-Oropeza, O.; Johnson, A. F.; Lundsten, L.

2015-12-01

Los Frailes submarine canyon is located at the south boundary of the Cabo Pulmo National Marine Park on the southeast tip of the Baja California Peninsula. During the Monterey Bay Aquarium Research Institute (MBARI) 2015 Gulf of California expedition we used an autonomous underwater vehicle (AUV) to map this canyon from 50 m to 450 m depths, and then explored the canyon with a small remotely operated vehicle (ROV). This three day R/V Rachel Carson cruise was a collaboration with the Center for Marine Biodiversity and Conservation at Scripps Institution of Oceanography and the Centro para la Biodiversidad Marina y la Conservación in La Paz. The MBARI AUV D. Allan B. collected high resolution bathymetry, sidescan, and subbottom profiles of Los Frailes submarine canyon and part of the north Cabo Pulmo deep reef. In order to safely generate a 1-m lateral resolution multibeam bathymetry map in the nearshore high relief terrain, the mapping operations consisted of an initial short survey following the 100-m isobath followed by a series of short, incremental AUV missions located on the deep edge of the new AUV bathymetry. The MBARI Mini-ROV was used to explore the submarine canyon within the detailed map created by the MBARI AUV. The Mini-ROV is a 1.2-m-long, 350 kg, 1,500-m-depth-rated ROV designed and constructed by MBARI. It is controlled by six 600-watt thrusters and is equipped with a high-definition video camera and navigation sensors. This small ROV carries less accurate, lower cost navigation sensors than larger vehicles. We implemented new algorithms to localize combining Doppler velocity log sensor data and low-cost MEMS-based inertial sensor data with sporadic ultra-short baseline position measurements to provide a high accuracy position estimation. The navigation performance allowed us to colocate the ROV video imagery with the 1-m resolution bathymetric map of the submarine canyon. Upper Los Frailes Canyon is rugged and, aside from small sand pockets along

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-10-01

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

The human factor in the operation of nuclear powered submarines

International Nuclear Information System (INIS)

Dambier, M.

1982-05-01

The conditions characterizing the operation of nuclear powered submarines are described and the precautionary measures suitable to reduce the incidence of human errors and their consequences are explained

Submarine slope failures due to pipe structure formation.

Science.gov (United States)

Elger, Judith; Berndt, Christian; Rüpke, Lars; Krastel, Sebastian; Gross, Felix; Geissler, Wolfram H

2018-02-19

There is a strong spatial correlation between submarine slope failures and the occurrence of gas hydrates. This has been attributed to the dynamic nature of gas hydrate systems and the potential reduction of slope stability due to bottom water warming or sea level drop. However, 30 years of research into this process found no solid supporting evidence. Here we present new reflection seismic data from the Arctic Ocean and numerical modelling results supporting a different link between hydrates and slope stability. Hydrates reduce sediment permeability and cause build-up of overpressure at the base of the gas hydrate stability zone. Resulting hydro-fracturing forms pipe structures as pathways for overpressured fluids to migrate upward. Where these pipe structures reach shallow permeable beds, this overpressure transfers laterally and destabilises the slope. This process reconciles the spatial correlation of submarine landslides and gas hydrate, and it is independent of environmental change and water depth.

Simple models for the simulation of submarine melt for a Greenland glacial system model

Science.gov (United States)

Beckmann, Johanna; Perrette, Mahé; Ganopolski, Andrey

2018-01-01

Two hundred marine-terminating Greenland outlet glaciers deliver more than half of the annually accumulated ice into the ocean and have played an important role in the Greenland ice sheet mass loss observed since the mid-1990s. Submarine melt may play a crucial role in the mass balance and position of the grounding line of these outlet glaciers. As the ocean warms, it is expected that submarine melt will increase, potentially driving outlet glaciers retreat and contributing to sea level rise. Projections of the future contribution of outlet glaciers to sea level rise are hampered by the necessity to use models with extremely high resolution of the order of a few hundred meters. That requirement in not only demanded when modeling outlet glaciers as a stand alone model but also when coupling them with high-resolution 3-D ocean models. In addition, fjord bathymetry data are mostly missing or inaccurate (errors of several hundreds of meters), which questions the benefit of using computationally expensive 3-D models for future predictions. Here we propose an alternative approach built on the use of a computationally efficient simple model of submarine melt based on turbulent plume theory. We show that such a simple model is in reasonable agreement with several available modeling studies. We performed a suite of experiments to analyze sensitivity of these simple models to model parameters and climate characteristics. We found that the computationally cheap plume model demonstrates qualitatively similar behavior as 3-D general circulation models. To match results of the 3-D models in a quantitative manner, a scaling factor of the order of 1 is needed for the plume models. We applied this approach to model submarine melt for six representative Greenland glaciers and found that the application of a line plume can produce submarine melt compatible with observational data. Our results show that the line plume model is more appropriate than the cone plume model for simulating

The esa earth explorer land surface processes and interactions mission

Science.gov (United States)

Labandibar, Jean-Yves; Jubineau, Franck; Silvestrin, Pierluigi; Del Bello, Umberto

2017-11-01

The European Space Agency (ESA) is defining candidate missions for Earth Observation. In the class of the Earth Explorer missions, dedicated to research and pre-operational demonstration, the Land Surface Processes and Interactions Mission (LSPIM) will acquire the accurate quantitative measurements needed to improve our understanding of the nature and evolution of biosphere-atmosphere interactions and to contribute significantly to a solution of the scaling problems for energy, water and carbon fluxes at the Earth's surface. The mission is intended to provide detailed observations of the surface of the Earth and to collect data related to ecosystem processes and radiation balance. It is also intended to address a range of issues important for environmental monitoring, renewable resources assessment and climate models. The mission involves a dedicated maneuvering satellite which provides multi-directional observations for systematic measurement of Land Surface BRDF (BiDirectional Reflectance Distribution Function) of selected sites on Earth. The satellite carries an optical payload : PRISM (Processes Research by an Imaging Space Mission), a multispectral imager providing reasonably high spatial resolution images (50 m over 50 km swath) in the whole optical spectral domain (from 450 nm to 2.35 μm with a resolution close to 10 nm, and two thermal bands from 8.1 to 9.1 μm). This paper presents the results of the Phase A study awarded by ESA, led by ALCATEL Space Industries and concerning the design of LSPIM.

Submarine canyons along the upper Sardinian slope (Central Western Mediterranean) as repositories for derelict fishing gears.

Science.gov (United States)

Cau, Alessandro; Alvito, Andrea; Moccia, Davide; Canese, Simonepietro; Pusceddu, Antonio; Rita, Cannas; Angiolillo, Michela; Follesa, Maria C

2017-10-15

By means of ROV surveys, we assessed the quantity, composition and bathymetric distribution of marine litter in 17 sites along the Sardinian continental margin (Central Western Mediterranean) at depths ranging from 100 to 480m. None of the investigated sites was litter free, but the mean density of litter (0.0175±0.0022itemsm -2 ) was lower than that reported from other Tyrrhenian regions. The difference in the total litter density among sites was negligible, but the density of derelict fishing gear (DFG) items (most of which ascribable to small scale fishery) in submarine canyons was higher in submarine canyons than in other habitats. Our result suggest that submarine canyons (known to be highly vulnerable ecosystems) act as major repositories of DFGs, and, therefore, we anticipate the need of specific measures aimed at minimizing the loss and abandonment of DFGs in submarine canyons. Copyright © 2017 Elsevier Ltd. All rights reserved.

Self-directed questions to improve students' ability in solving chemical problems

Science.gov (United States)

Sanjaya, Rahmat Eko; Muna, Khairiatul; Suharto, Bambang; Syahmani

2017-12-01

Students' ability in solving chemical problems is seen from their ability to solve chemicals' non-routine problems. It is due to learning faced directly on non-routine problems will generate a meaningful learning for students. Observations in Banjarmasin Public High School 1 (SMA Negeri 1 Banjarmasin) showed that students did not give the expected results when they were given the non-routine problems. Learning activities by emphasizing problem solving was implemented based on the existence of knowledge about cognition and regulation of cognition. Both of these elements are components of metacognition. The self-directed question is a strategy that involves metacognition in solving chemical problems. This research was carried out using classroom action research design in two cycles. Each cycle consists of four stages: planning, action, observation and reflection. The subjects were 34 students of grade XI-4 at majoring science (IPA) of SMA Negeri 1 Banjarmasin. The data were collected using tests of the students' ability in problem solving and non-tests instrument to know the process of implementation of the actions. Data were analyzed with descriptivequantitativeand qualitative analysis. The ability of students in solving chemical problems has increased from an average of 37.96 in cycle I became 61.83 in cycle II. Students' ability to solve chemical problems is viewed based on their ability to answer self-directed questions. Students' ability in comprehension questions increased from 73.04 in the cycle I became 96.32 in cycle II. Connection and strategic questions increased from 54.17 and 16.50 on cycle I became 63.73 and 55.23 on cycle II respectively. In cycle I, reflection questions were 26.96 and elevated into 36.27 in cycle II. The self-directed questions have the ability to help students to solve chemical problems through metacognition questions. Those questions guide students to find solutions in solving chemical problems.

Effect of submarine canyons on tsunami heights, currents and run-up off the southeast coast of India

Digital Repository Service at National Institute of Oceanography (India)

JayaKumar, S.; ManiMurali, R.; Baldock, T.E.

Tsunami numerical model studies are mostly focused on inundation and run-up onto the coast. Fewer studies have been aimed at investigating role of submarine canyons on the tsunami heights, currents and run-up. The influence of submarine canyons...

Direct and inverse source problems for a space fractional advection dispersion equation

KAUST Repository

Aldoghaither, Abeer

2016-05-15

In this paper, direct and inverse problems for a space fractional advection dispersion equation on a finite domain are studied. The inverse problem consists in determining the source term from final observations. We first derive the analytic solution to the direct problem which we use to prove the uniqueness and the unstability of the inverse source problem using final measurements. Finally, we illustrate the results with a numerical example.

Navy Ohio Replacement (SSBN[X]) Ballistic Missile Submarine Program: Background and Issues for Congress

Science.gov (United States)

2016-04-05

Navy Ohio Replacement (SSBN[X]) Ballistic Missile Submarine Program: Background and Issues for Congress Ronald O’Rourke Specialist in Naval...Affairs April 5, 2016 Congressional Research Service 7-5700 www.crs.gov R41129 Navy Ohio Replacement (SSBN[X]) Ballistic Missile Submarine...1,091.1 million in research and development funding for the Ohio replacement program (ORP), a program to design and build a new class of 12 ballistic

At Periscope Depth: Exploring Submarine Proliferation In Southeast Asia

Science.gov (United States)

2015-09-01

papers and op-eds; and relevant books . This thesis will not include human subjects because the scope of the research will not permit gathering...Soviet-built submarines required.36 Furthermore, the hulls were purchased secondhand and thus had a shortened

Health and environmental risk assessment associated with a potential recovery of the Russian submarine K-27

Energy Technology Data Exchange (ETDEWEB)

Hosseini, A.; Amundsen, I.; Brown, J.E.; Dowdall, M.; Standring, W. [Norwegian Radiation Protection Authority/CERAD CoE (Norway); Bartnicki, J. [Norwegian Meteorological Institute/CERAD CoE (Norway); Karcher, M. [O.A.Sys - Ocean Atmosphere Systems GmbH (Germany); Lind, O.C.; Salbu, B. [Norwegian University of Life Sciences/CERAD CoE (Norway)

2014-07-01

The nuclear submarine K-27 is one of several objects with spent nuclear fuel (SNF) which has been dumped in the Arctic. It contained two liquid metal reactors (LMRs) of 70 MW maximum thermal power each and used Pb-Bi as the coolant. The reactors were loaded with 180 kg of U-235 at an enrichment of 90 %. In September 1981, the submarine was sunk in the shallow waters of Stepovoy Fjord at an estimated depth of 30 m. Concerns have been expressed by various parties regarding the issue of dumped nuclear waste in the Kara Sea and in particular the submarine K-27. To address these concerns and to provide a better basis for evaluating possible radiological impact (especially as a consequence of a potential recovery of the submarine), an environmental impact assessment has been undertaken. The study is based on construction of different hypothetical accident scenarios and evaluating possible associated consequences for human and the environment. In general, three main scenarios seem probable and thus appropriate for consideration. One is the 'zero- alternative', i.e. investigate the current and future impact assuming no interventions. The second considers an accidental scenario involving the raising of the submarine and the third an accidental scenario related to the transportation of the submarine to shore for defueling. With regards to the accidental scenarios related to raising and transportation of the submarine, two alternatives can be considered depending on where and how a hypothetical accident will take place and whether the subsequent releases occur under water or at the water surface. The issue of an uncontrolled chain reaction occurring as a result of a potential recovery of the submarine will be included in the assessment. The work includes application of state of the art 3D hydrodynamic and atmospheric dispersion models to investigate the transport, distribution and fate of relevant radionuclides following a hypothetical accident in aquatic and

Mars Relay Satellite: Key to Enabling Low-Cost Exploration Missions

Science.gov (United States)

Hastrup, R.; Cesarone, R.; Miller, A.

1993-01-01

Recently, there has been increasing evidence of a renewed focus on Mars exploration both by NASA and the international community. The thrust of this renewed interest appears to be manifesting itself in numerous low-cost missions employing small, light weight elements, which utilize advanced technologies including integrated microelectronics. A formidable problem facing these low-cost missions is communications with Earth. Providing adequate direct-link performance has very significant impacts on spacecraft power, pointing, mass and overall complexity. Additionally, for elements at or near the surface of Mars, there are serious connectivity constraints, especially at higher latitudes, which lose view of Earth for up to many months at a time. This paper will discuss the role a Mars relay satellite can play in enabling and enhancing low-cost missions to Mars...

Numerical calculation of hydrodynamic characteristics of tidal currents for submarine excavation engineering in coastal area

Directory of Open Access Journals (Sweden)

Jian-hua Li

2016-04-01

Full Text Available In coastal areas with complicated flow movement, deposition and scour readily occur in submarine excavation projects. In this study, a small-scale model, with a high resolution in the vertical direction, was used to simulate the tidal current around a submarine excavation project. The finite volume method was used to solve Navier-Stokes equations and the Reynolds stress transport equation, and the entire process of the tidal current was simulated with unstructured meshes, generated in the irregular shape area, and structured meshes, generated in other water areas. The meshes near the bottom and free surface were densified with a minimum layer thickness of 0.05 m. The volume of fluid method was used to track the free surface, the volume fraction of cells on the upstream boundary was obtained from the volume fraction of adjacent cells, and that on the downstream boundary was determined by the water level process. The numerical results agree with the observed data, and some conclusions can be drawn: after the foundation trench excavation, the flow velocity decreases quite a bit through the foundation trench, with reverse flow occurring on the lee slope in the foundation trench; the swirling flow impedes inflow, leading to the occurrence of dammed water above the foundation trench; the turbulent motion is stronger during ebbing than in other tidal stages, the range with the maximum value of turbulent viscosity, occurring on the south side of the foundation trench at maximum ebbing, is greater than those in other tidal stages in a tidal cycle, and the maximum value of Reynolds shear stress occurs on the south side of the foundation trench at maximum ebbing in a tidal cycle. The numerical calculation method shows a strong performance in simulation of the hydrodynamic characteristics of tidal currents in the foundation trench, providing a basis for submarine engineering construction in coastal areas.

Robustness of mission plans for unmanned aircraft

Science.gov (United States)

Niendorf, Moritz

This thesis studies the robustness of optimal mission plans for unmanned aircraft. Mission planning typically involves tactical planning and path planning. Tactical planning refers to task scheduling and in multi aircraft scenarios also includes establishing a communication topology. Path planning refers to computing a feasible and collision-free trajectory. For a prototypical mission planning problem, the traveling salesman problem on a weighted graph, the robustness of an optimal tour is analyzed with respect to changes to the edge costs. Specifically, the stability region of an optimal tour is obtained, i.e., the set of all edge cost perturbations for which that tour is optimal. The exact stability region of solutions to variants of the traveling salesman problems is obtained from a linear programming relaxation of an auxiliary problem. Edge cost tolerances and edge criticalities are derived from the stability region. For Euclidean traveling salesman problems, robustness with respect to perturbations to vertex locations is considered and safe radii and vertex criticalities are introduced. For weighted-sum multi-objective problems, stability regions with respect to changes in the objectives, weights, and simultaneous changes are given. Most critical weight perturbations are derived. Computing exact stability regions is intractable for large instances. Therefore, tractable approximations are desirable. The stability region of solutions to relaxations of the traveling salesman problem give under approximations and sets of tours give over approximations. The application of these results to the two-neighborhood and the minimum 1-tree relaxation are discussed. Bounds on edge cost tolerances and approximate criticalities are obtainable likewise. A minimum spanning tree is an optimal communication topology for minimizing the cumulative transmission power in multi aircraft missions. The stability region of a minimum spanning tree is given and tolerances, stability balls

Enhancement of submarine pressure hull steel ultrasonic inspection using imaging and artificial intelligence

Science.gov (United States)

Hay, D. Robert; Brassard, Michel; Matthews, James R.; Garneau, Stephane; Morchat, Richard

1995-06-01

The convergence of a number of contemporary technologies with increasing demands for improvements in inspection capabilities in maritime applications has created new opportunities for ultrasonic inspection. An automated ultrasonic inspection and data collection system APHIUS (automated pressure hull intelligent ultrasonic system), incorporates hardware and software developments to meet specific requirements for the maritime vessels, in particular, submarines in the Canadian Navy. Housed within a hardened portable computer chassis, instrumentation for digital ultrasonic data acquisition and transducer position measurement provide new capabilities that meet more demanding requirements for inspection of the aging submarine fleet. Digital data acquisition enables a number of new important capabilites including archiving of the complete inspection session, interpretation assistance through imaging, and automated interpretation using artificial intelligence methods. With this new reliable inspection system, in conjunction with a complementary study of the significance of real defect type and location, comprehensive new criteria can be generated which will eliminate unnecessary defect removal. As a consequence, cost savings will be realized through shortened submarine refit schedules.

A real two-phase submarine debris flow and tsunami

International Nuclear Information System (INIS)

Pudasaini, Shiva P.; Miller, Stephen A.

2012-01-01

The general two-phase debris flow model proposed by Pudasaini is employed to study subaerial and submarine debris flows, and the tsunami generated by the debris impact at lakes and oceans. The model, which includes three fundamentally new and dominant physical aspects such as enhanced viscous stress, virtual mass, and generalized drag (in addition to buoyancy), constitutes the most generalized two-phase flow model to date. The advantage of this two-phase debris flow model over classical single-phase, or quasi-two-phase models, is that the initial mass can be divided into several parts by appropriately considering the solid volume fraction. These parts include a dry (landslide or rock slide), a fluid (water or muddy water; e.g., dams, rivers), and a general debris mixture material as needed in real flow simulations. This innovative formulation provides an opportunity, within a single framework, to simultaneously simulate the sliding debris (or landslide), the water lake or ocean, the debris impact at the lake or ocean, the tsunami generation and propagation, the mixing and separation between the solid and fluid phases, and the sediment transport and deposition process in the bathymetric surface. Applications of this model include (a) sediment transport on hill slopes, river streams, hydraulic channels (e.g., hydropower dams and plants); lakes, fjords, coastal lines, and aquatic ecology; and (b) submarine debris impact and the rupture of fiber optic, submarine cables and pipelines along the ocean floor, and damage to offshore drilling platforms. Numerical simulations reveal that the dynamics of debris impact induced tsunamis in mountain lakes or oceans are fundamentally different than the tsunami generated by pure rock avalanches and landslides. The analysis includes the generation, amplification and propagation of super tsunami waves and run-ups along coastlines, debris slide and deposition at the bottom floor, and debris shock waves. It is observed that the

A real two-phase submarine debris flow and tsunami

Energy Technology Data Exchange (ETDEWEB)

Pudasaini, Shiva P.; Miller, Stephen A. [Department of Geodynamics and Geophysics, Steinmann Institute, University of Bonn Nussallee 8, D-53115, Bonn (Germany)

2012-09-26

The general two-phase debris flow model proposed by Pudasaini is employed to study subaerial and submarine debris flows, and the tsunami generated by the debris impact at lakes and oceans. The model, which includes three fundamentally new and dominant physical aspects such as enhanced viscous stress, virtual mass, and generalized drag (in addition to buoyancy), constitutes the most generalized two-phase flow model to date. The advantage of this two-phase debris flow model over classical single-phase, or quasi-two-phase models, is that the initial mass can be divided into several parts by appropriately considering the solid volume fraction. These parts include a dry (landslide or rock slide), a fluid (water or muddy water; e.g., dams, rivers), and a general debris mixture material as needed in real flow simulations. This innovative formulation provides an opportunity, within a single framework, to simultaneously simulate the sliding debris (or landslide), the water lake or ocean, the debris impact at the lake or ocean, the tsunami generation and propagation, the mixing and separation between the solid and fluid phases, and the sediment transport and deposition process in the bathymetric surface. Applications of this model include (a) sediment transport on hill slopes, river streams, hydraulic channels (e.g., hydropower dams and plants); lakes, fjords, coastal lines, and aquatic ecology; and (b) submarine debris impact and the rupture of fiber optic, submarine cables and pipelines along the ocean floor, and damage to offshore drilling platforms. Numerical simulations reveal that the dynamics of debris impact induced tsunamis in mountain lakes or oceans are fundamentally different than the tsunami generated by pure rock avalanches and landslides. The analysis includes the generation, amplification and propagation of super tsunami waves and run-ups along coastlines, debris slide and deposition at the bottom floor, and debris shock waves. It is observed that the

Non-linearity aspects in the design of submarine pipelines

NARCIS (Netherlands)

Fernández, M.L.

1981-01-01

An arbitrary attempt has been made to classify and discuss some non-linearity aspects related to design, construction and operation of submarine pipelines. Non-linearities usually interrelate and take part of a comprehensive design, making difficult to quantify their individual influence or

Environmental Analysis of U.S. Navy Submarine Solid Waste Discharges. Report of Findings

Science.gov (United States)

1997-05-01

generation rates between the USS Cincinnati and the USS Kamehameha (shown in table 6-1) were described in the NNS study (1994) as due to differences in crew...habits, menus, variations in at-sea time, and differences in waste reduction efforts. It was noted that some boats, including the USS Kamehameha , have...kg·person-l·d-l) PCMG(%) (kg·person-l·d-l) PCMG(%) Submarine Submarine USS Cincinnati USS Kamehameha Cardboard 0.21 0.05 Paper(FC) 0.06 0.06 Paper(NFC

Submarine Tailings Disposal (STD—A Review

Directory of Open Access Journals (Sweden)

Bernhard Dold

2014-07-01

Full Text Available The mining industry is a fundamental industry involved in the development of modern society, but is also the world’s largest waste producer. This role will be enhanced in the future, because ore grades are generally decreasing, thus leading to increases in the waste/metal production ratio. Mine wastes deposited on-land in so-called tailings dams, impoundments or waste-dumps have several associated environmental issues that need to be addressed (e.g., acid mine drainage formation due to sulphide oxidation, geotechnical stability, among others, and social concerns due to land use during mining. The mining industry recognizes these concerns and is searching for waste management alternatives for the future. One option used in the past was the marine shore or shallow submarine deposition of this waste material in some parts of the world. After the occurrence of some severe environmental pollution, today the deposition in the deep sea (under constant reducing conditions is seen as a new, more secure option, due to the general thought that sulphide minerals are geochemically stable under the reduced conditions prevailing in the deep marine environment. This review highlights the mineralogical and geochemical issues (e.g., solubility of sulphides in seawater; reductive dissolution of oxide minerals under reducing conditions, which have to be considered when evaluating whether submarine tailings disposal is a suitable alternative for mine waste.

Assessment of the environmental consequences of demolishing two Russian nuclear submarines

International Nuclear Information System (INIS)

2004-01-01

Norway has financed the demolition of two Russian Viktor II nuclear submarines through the Government's plan of action for nuclear issues. The British company Enviros Consulting has made an independent assessment of the environmental consequences of the project, which has been evaluated by the Foreign Department in cooperation with The Norwegian Radiation Protection Authority (NRPA). The consequence assessment has examined the health, environment and safety aspects of the entire demolition process, from towing the submarine to delivering the rubbish at the destination site. From Russian documentation and by visiting the shipyards it has been concluded that the demolition has been carried out in agreement with Russian law and in accordance with international instructions

Boulder emplacement and remobilisation by cyclone and submarine landslide tsunami waves near Suva City, Fiji

Science.gov (United States)

Lau, A. Y. Annie; Terry, James P.; Ziegler, Alan; Pratap, Arti; Harris, Daniel

2018-02-01

The characteristics of a reef-top boulder field created by a local submarine landslide tsunami are presented for the first time. Our examination of large reef-derived boulders deposited by the 1953 tsunami near Suva City, Fiji, revealed that shorter-than-normal-period tsunami waves generated by submarine landslides can create a boulder field resembling a storm boulder field due to relatively short boulder transport distances. The boulder-inferred 1953 tsunami flow velocity is estimated at over 9 m s- 1 at the reef edge. Subsequent events, for example Cyclone Kina (1993), appear to have remobilised some large boulders. While prior research has demonstrated headward retreat of Suva Canyon in response to the repeated occurrence of earthquakes over the past few millennia, our results highlight the lingering vulnerability of the Fijian coastlines to high-energy waves generated both in the presence (tsunami) and absence (storm) of submarine failures and/or earthquakes. To explain the age discrepancies of U-Th dated coral comprising the deposited boulders, we introduce a conceptual model showing the role of repeated episodes of tsunamigenic submarine landslides in removing reef front sections through collapse. Subsequent high-energy wave events transport boulders from exposed older sections of the reef front onto the reef where they are deposited as 'new' boulders, alongside freshly detached sections of the living reef. In similar situations where anachronistic deposits complicate the deposition signal, age-dating of the coral boulders should not be used as a proxy for determining the timing of the submarine landslides or the tsunamis that generated them.

Space missions to the exoplanets: Will they ever be possible

Science.gov (United States)

Genta, Giancarlo

There is no doubt that the discovery of exoplanets has made interstellar space mission much more interesting than they were in the past. The possible discovery of a terrestrial type plane at a reasonable distance will give a strong impulse in this direction. However, there are doubts that such long range space mission will ever become feasible at all and, in case they will be, it is impossible to forecast a timeframe for them. At present, precursor interstellar missions are planned, but they fall way short from yielding interesting information about exoplanets, except perhaps in the case of missions to the focal line of the Sun’s gravitational lens, whose usefulness in this context is still to be demonstrated. They are anyway an essential step in the roadmap toward interstellar missions. Often the difficulties linked with interstellar missions are considered as related with the huge quantity of energy required for reaching the target star system within a reasonable timeframe. While this may well be a showstopper, it is not the only problem to be solved to make them possible. Two other issues are those linked with the probe’s autonomy and the telecommunications required to transmit large quantities of information at those distances. Missions to the exoplanets may be subdivided in the following categories: 1) robotic missions to the destination system, including flybys; 2) robotic missions including landing on an exoplanet; 3) robotic sample return missions; 4) human missions. The main problem to be solved for missions of type 1 is linked with propulsion and with energy availability, while autonomy (artificial intelligence) and telecommunication problems are more or less manageable with predictable technologies. Missions of type 2 are more demanding for what propulsion is concerned, but above all require a much larger artificial intelligence and also will generate a large amount of data, whose transmission back to Earth may become a problem. The suggestion of

Searching for structural medium changes during the 2011 El Hierro (Spain) submarine eruption

Science.gov (United States)

Sánchez-Pastor, Pilar S.; Schimmel, Martin; López, Carmen

2017-04-01

Submarine volcanic eruptions are often difficult to study due to their restricted access that usually inhibits direct observations. That happened with the 2011 El Hierro eruption, which is the first eruption that has been tracked in real time in Canary Islands. For instance, despite the real-time tracking it was not possible to determine the exact end of the eruption. Besides, volcanic eruptions involve many dynamic (physical and chemical) processes, which cause structural changes in the surrounding medium that we expect to observe and monitor through passive seismic approaches. The purpose of this study is to detect and analyse these changes as well as to search for precursory signals to the eruption itself using ambient noise auto and cross-correlations. We employ different correlation strategies (classical and phase cross-correlation) and apply them to field data recorded by the IGN network during 2011 and 2012. The different preprocessing and processing steps are tested and compared to better understand the data, to find the robust signatures, and to define a routine work procedure. One of the problems we face is the presence of volcanic tremors, which cause a varying seismic response that we can not attribute to structural changes. So far, structural changes could not be detected unambiguously and we present our ongoing research in this field.

Evaluation of the radiologic potential due to the nuclear submarine visits to the Rio de Janeiro port

International Nuclear Information System (INIS)

Pereira, Jose Francisco

2004-01-01

Brazil is signatory of international protocols related to the visit of nuclear-powered vessels, aircraft carriers and submarines to Brazilian ports. The submarines, during their stay in Brazilian ports, inform that there is no release of radioactive material to the environment. However, the possibility of occurrence of accidents with environmental releases from PWR reactors is real. Between 1993 and 2003, 13 nuclear submarines visited Brazilian ports. This work aimed to evaluate the potential impact due to the visits of nuclear-powered ships and submarines to the port of the city of Rio de Janeiro, in relation to releases of radioactive materials to the environment, considering both routine releases and accidental situations. The models selected to perform the assessments took into account the scenarios to be simulated. Simple, but conservative methodologies were used for the evaluation of routine releases. For accidental releases, the dynamics of the materials dispersion into the environment were considered. The present study was mainly focalized on the initial phase of an accident. The doses for the crew of the Brazilian navy ships, for IRD teams performing environmental monitoring, and for the population around the Guanabara Bay, close to the points of anchorage, were assessed. The results indicated that, in normal operational conditions, no significant radiological impact due to the visit of nuclear submarines to the port of the city of Rio de Janeiro is expected, even considering the occurrence of small routine radionuclide releases. The analysis of accidental releases, however, indicated that the submarines should be located at a minimum distance of 2,5 km from inhabited areas in the coast of the Guanabara Bay. The need for environmental control and training of the teams involved in the attendance of the submarines, during the period of their visit, was also considered. The need for revising the procedures for the preoperational surveys to be performed at the

The Ferris Educational Mission Obligations and Directions.

Science.gov (United States)

Griffin, Edward M.

In September 1971, the members of the Educational Planning Committee of Ferris State College held a seminar to determine Ferris priorities for the 1971-72 academic year. This document takes into consideration the first of these priorities--the educational responsibilities and missions of Ferris State College. To this end, the document is divided…

Research on Big Data Attribute Selection Method in Submarine Optical Fiber Network Fault Diagnosis Database

Directory of Open Access Journals (Sweden)

Chen Ganlang

2017-11-01

Full Text Available At present, in the fault diagnosis database of submarine optical fiber network, the attribute selection of large data is completed by detecting the attributes of the data, the accuracy of large data attribute selection cannot be guaranteed. In this paper, a large data attribute selection method based on support vector machines (SVM for fault diagnosis database of submarine optical fiber network is proposed. Mining large data in the database of optical fiber network fault diagnosis, and calculate its attribute weight, attribute classification is completed according to attribute weight, so as to complete attribute selection of large data. Experimental results prove that ,the proposed method can improve the accuracy of large data attribute selection in fault diagnosis database of submarine optical fiber network, and has high use value.

Ultra-high chlorine in submarine Kı̄lauea glasses: Evidence for direct assimilation of brine by magma

Science.gov (United States)

Coombs, Michelle L.; Sisson, Thomas W.; Kimura, Jun-Ichi

2004-01-01

Basaltic glass grains from the submarine south flank of Kı̄lauea, Hawai′i, have Cl concentrations of 0.01–1.68 wt%, the latter being the highest Cl content yet recorded for a Hawaiian glass. The high-Cl glass grains are products of brine assimilation by tholeiite magma. The glasses are grains in a sandstone clast from bedded breccias draping the southwestern margin of Kı̄lauea’s submarine midslope bench. The clast contains two distinct suites of glass grains: abundant degassed tholeiites, perhaps derived from subaerial lavas of Mauna Loa that shattered upon ocean entry, and a smaller population of Kea-type tholeiite (n=17 analyzed) that erupted subaqueously, based on elevated S (780–1050 ppm), H2O (0.42–1.27 wt%), and CO2 (1000 ppm, six >5000 ppm, and two grains have >10 000 ppm dissolved Cl. Abundances of H2O, Na2O, K2O, and several trace elements increase regularly with Cl concentration, and we estimate that Cl enrichment was due to up to 13 wt% addition of a brine consisting of 78% H2O (wt), 13% Cl, 4.4% Na, 2.6% K, 2.6% Ca, 620 ppm Ba, 360 ppm Sr, 65 ppm Rb, and 7 ppm Pb. The large amounts of brine addition argue against bulk assimilation of low-porosity brine-bearing rock. The brine’s composition is appropriate for a seawater-derived hydrothermal fluid that reacted with basaltic wall rocks at T>100°C, losing Mg and S and gaining K, Ca, Rb, Ba, Sr, and Pb, followed by phase separation near 500°C and ∼50 MPa (5 km below sea level at hydrostatic pressure). Brine was assimilated at or near the depth it formed, as estimated on petrologic grounds, but under lithostatic conditions. The highest extents of assimilation either forced volatile saturation of the magma or enriched already coexisting magmatic vapor in H2O. Possible mechanisms for assimilation are: (1) forcible injection of brine into magma during bursting of overpressured pockets heated by new dikes, or (2) intrusion of magma into lenses or sills occupied by trapped brine.

New infrastructure at Alboran island (Western Mediterranean): a submarine and on-land Geophysical Observatory

Science.gov (United States)

Pazos, Antonio; Martín Davila, José; Buforn, Elisa; Jesús García Fernández, Maria; Bullón, Mercedes; Gárate, Jorge

2010-05-01

The Eurasian-African plate boundary crosses the called "Ibero-Maghrebian" region from San Vicente Cape (SW Portugal) to Tunisia including the South of Iberia, Alboran Sea, and northern of Morocco and Algeria. The low convergence rate at this plate boundary produces a continuous moderate seismic activity of low magnitude and shallow depth, where the occurrence of large earthquakes is separated by long time intervals. In this region, there are also intermediate and very deep earthquakes. Since more than hundred years ago San Fernando Naval Observatory (ROA), in collaboration with other Institutes, has deployed different geophysical and geodetic equipment in the Southern Spain - North-western Africa area in order to study this broad deformation. Currently a Broad Band seismic net (Western Mediterranean, WM net), a permanent geodetic GPS net and a Geomagnetic Observatory have been installed by ROA in this area. To complement the available data, since past October a permanent marine-on land geophysical observatory is being installed by ROA in Alboran Island and surrounding marine zones. Till now the following facilities has been installed: • Submarine: 2 km submarine fibre optics cable (power and data transmission); Broad Band Seismometer (CMG-3T, buried); Accelerometer (Guralp 3 channels), buried); Differential Pressure Gauge (DPG); Thermometer. • On land: Permanent geodetic GPS station; Automatic meteorological station; Data acquisition system for submarine equipment; Satellite Data Transmission system. Data are already being transmitted in real time to ROA headquarters via satellite Intranet. The marine part, currently installed in a 50 m depth platform, has been designed to be enlarged by extending the cable to greater depths and/or installing additional submarine equipment, such a way in short an ADCP profiler will be installed. In this work we aim to show the present status, scientific possibilities and the next future plans of this submarine-on land

Submarine Upward Looking Sonar Ice Draft Profile Data and Statistics

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of upward looking sonar draft data collected by submarines in the Arctic Ocean. It includes data from both U.S. Navy and Royal Navy...

Development and validation of a modified Hybrid-III six-year-old dummy model for simulating submarining in motor-vehicle crashes.

Science.gov (United States)

Hu, Jingwen; Klinich, Kathleen D; Reed, Matthew P; Kokkolaras, Michael; Rupp, Jonathan D

2012-06-01

In motor-vehicle crashes, young school-aged children restrained by vehicle seat belt systems often suffer from abdominal injuries due to submarining. However, the current anthropomorphic test device, so-called "crash dummy", is not adequate for proper simulation of submarining. In this study, a modified Hybrid-III six-year-old dummy model capable of simulating and predicting submarining was developed using MADYMO (TNO Automotive Safety Solutions). The model incorporated improved pelvis and abdomen geometry and properties previously tested in a modified physical dummy. The model was calibrated and validated against four sled tests under two test conditions with and without submarining using a multi-objective optimization method. A sensitivity analysis using this validated child dummy model showed that dummy knee excursion, torso rotation angle, and the difference between head and knee excursions were good predictors for submarining status. It was also shown that restraint system design variables, such as lap belt angle, D-ring height, and seat coefficient of friction (COF), may have opposite effects on head and abdomen injury risks; therefore child dummies and dummy models capable of simulating submarining are crucial for future restraint system design optimization for young school-aged children. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

An IKBS approach to surveillance for naval nuclear submarine propulsion

International Nuclear Information System (INIS)

Cadas, C.N.; Bowskill, J.; Mayfield, T.; Clarke, J.C.

1993-01-01

This paper describes work being carried out to develop an IKBS for use in surveillance of naval nuclear submarine propulsion plant. In recent years, modern process plants have increased automation and installed surveillance equipment while reducing the level of manpower operating and monitoring the plant. As a result, some of the local watchkeeping tasks have been transferred to control room operators, and the data reduction and warning filtering expertise inherent in local plant operators has been lost, while an additional workload has been placed upon operators. The surveillance systems installed to date have therefore been less usable than anticipated. The solution being achieved for submarine power plant is to introduce IKBS into surveillance to replace lost expertise, i.e. to return to a situation in which operators receive small amounts of high quality information rather than large amounts of low quality information

Cascadia Onshore-Offshore Site Response, Submarine Sediment Mobilization, and Earthquake Recurrence

Science.gov (United States)

Gomberg, J.

2018-02-01

Local geologic structure and topography may modify arriving seismic waves. This inherent variation in shaking, or "site response," may affect the distribution of slope failures and redistribution of submarine sediments. I used seafloor seismic data from the 2011 to 2015 Cascadia Initiative and permanent onshore seismic networks to derive estimates of site response, denoted Sn, in low- and high-frequency (0.02-1 and 1-10 Hz) passbands. For three shaking metrics (peak velocity and acceleration and energy density) Sn varies similarly throughout Cascadia and changes primarily in the direction of convergence, roughly east-west. In the two passbands, Sn patterns offshore are nearly opposite and range over an order of magnitude or more across Cascadia. Sn patterns broadly may be attributed to sediment resonance and attenuation. This and an abrupt step in the east-west trend of Sn suggest that changes in topography and structure at the edge of the continental margin significantly impact shaking. These patterns also correlate with gravity lows diagnostic of marginal basins and methane plumes channeled within shelf-bounding faults. Offshore Sn exceeds that onshore in both passbands, and the steepest slopes and shelf coincide with the relatively greatest and smallest Sn estimates at low and high frequencies, respectively; these results should be considered in submarine shaking-triggered slope stability failure studies. Significant north-south Sn variations are not apparent, but sparse sampling does not permit rejection of the hypothesis that the southerly decrease in intervals between shaking-triggered turbidites and great earthquakes inferred by Goldfinger et al. (2012, 2013, 2016) and Priest et al. (2017) is due to inherently stronger shaking southward.

Evidence from acoustic imaging for submarine volcanic activity in 2012 off the west coast of El Hierro (Canary Islands, Spain)

Science.gov (United States)

Pérez, Nemesio M.; Somoza, Luis; Hernández, Pedro A.; de Vallejo, Luis González; León, Ricardo; Sagiya, Takeshi; Biain, Ander; González, Francisco J.; Medialdea, Teresa; Barrancos, José; Ibáñez, Jesús; Sumino, Hirochika; Nogami, Kenji; Romero, Carmen

2014-12-01

We report precursory geophysical, geodetic, and geochemical signatures of a new submarine volcanic activity observed off the western coast of El Hierro, Canary Islands. Submarine manifestation of this activity has been revealed through acoustic imaging of submarine plumes detected on the 20-kHz chirp parasound subbottom profiler (TOPAS PS18) mounted aboard the Spanish RV Hespérides on June 28, 2012. Five distinct "filament-shaped" acoustic plumes emanating from the flanks of mounds have been recognized at water depth between 64 and 88 m on a submarine platform located NW El Hierro. These plumes were well imaged on TOPAS profiles as "flares" of high acoustic contrast of impedance within the water column. Moreover, visible plumes composed of white rafts floating on the sea surface and sourcing from the location of the submarine plumes were reported by aerial photographs on July 3, 2012, 5 days after acoustic plumes were recorded. In addition, several geophysical and geochemical data support the fact that these submarine vents were preceded by several precursory signatures: (i) a sharp increase of the seismic energy release and the number of daily earthquakes of magnitude ≥2.5 on June 25, 2012, (ii) significant vertical and horizontal displacements observed at the Canary Islands GPS network (Nagoya University-ITER-GRAFCAN) with uplifts up to 3 cm from June 25 to 26, 2012, (iii) an anomalous increase of the soil gas radon activity, from the end of April until the beginning of June reaching peak values of 2.7 kBq/m3 on June 3, 2012, and (iv) observed positive peak in the air-corrected value of 3He/4He ratio monitored in ground waters (8.5 atmospheric 3He/4He ratio ( R A)) at the northwestern El Hierro on June 16, 2012. Combining these submarine and subaerial information, we suggest these plumes are the consequence of submarine vents exhaling volcanic gas mixed with fine ash as consequence of an event of rapid rise of volatile-rich magma beneath the NW submarine ridge

Direct sampling during multiple sediment density flows reveals dynamic sediment transport and depositional environment in Monterey submarine canyon

Science.gov (United States)

Maier, K. L.; Gales, J. A.; Paull, C. K.; Gwiazda, R.; Rosenberger, K. J.; McGann, M.; Lundsten, E. M.; Anderson, K.; Talling, P.; Xu, J.; Parsons, D. R.; Barry, J.; Simmons, S.; Clare, M. A.; Carvajal, C.; Wolfson-Schwehr, M.; Sumner, E.; Cartigny, M.

2017-12-01

Sediment density flows were directly sampled with a coupled sediment trap-ADCP-instrument mooring array to evaluate the character and frequency of turbidity current events through Monterey Canyon, offshore California. This novel experiment aimed to provide links between globally significant sediment density flow processes and their resulting deposits. Eight to ten Anderson sediment traps were repeatedly deployed at 10 to 300 meters above the seafloor on six moorings anchored at 290 to 1850 meters water depth in the Monterey Canyon axial channel during 6-month deployments (October 2015 - April 2017). Anderson sediment traps include a funnel and intervalometer (discs released at set time intervals) above a meter-long tube, which preserves fine-scale stratigraphy and chronology. Photographs, multi-sensor logs, CT scans, and grain size analyses reveal layers from multiple sediment density flow events that carried sediment ranging from fine sand to granules. More sediment accumulation from sediment density flows, and from between flows, occurred in the upper canyon ( 300 - 800 m water depth) compared to the lower canyon ( 1300 - 1850 m water depth). Sediment accumulated in the traps during sediment density flows is sandy and becomes finer down-canyon. In the lower canyon where sediment directly sampled from density flows are clearly distinguished within the trap tubes, sands have sharp basal contacts, normal grading, and muddy tops that exhibit late-stage pulses. In at least two of the sediment density flows, the simultaneous low velocity and high backscatter measured by the ADCPs suggest that the trap only captured the collapsing end of a sediment density flow event. In the upper canyon, accumulation between sediment density flow events is twice as fast compared to the lower canyon; it is characterized by sub-cm-scale layers in muddy sediment that appear to have accumulated with daily to sub-daily frequency, likely related to known internal tidal dynamics also measured

Active normal faults and submarine landslides in the Keelung Shelf off NE Taiwan

Directory of Open Access Journals (Sweden)

Ching-Hui Tsai

2018-01-01

Full Text Available The westernmost Okinawa Trough back-arc basin is located to the north of the Ryukyu islands and is situated above the northward dipping Ryukyu subducted slab. In the northern continental margin of the Okinawa Trough, the continental slope between the Keelung Valley and the Mein-Hua Submarine Canyon shows a steep angle and future slope failures are expected. The question is how slope failures will proceed? A sudden deep-seated slump or landslide would probably cause local tsunami and hit northern coast of Taiwan. To understand the probable submarine landslides, we conducted multi-channel seismic reflection, sub-bottom profilers, and multi-beam bathymetry surveys off NE Taiwan. Two general trends of shallow crustal faults are observed. The NE-SW trending faults generally follow the main structural trend of the Taiwan mountain belt. These faults are products of inversion tectonics of reverse faults from the former collisional thrust faults to post-collisional normal faults. Another trend of roughly E-W faults is consistent with the current N-S extension of the southern Okinawa Trough. The fault offsets in the eastern portion of the study area are more pronounced. No obvious basal surface of sliding is found beneath the continental margin. We conclude that the movement of the submarine landslides in the Keelung Shelf off northeastern Taiwan could be in a spread type. The submarine landslides mainly occur in the continental slope area and it is more obvious in the east than in the west of the Keelung Shelf.

Meta-Analysis of Data from the Submarine Ventilation Doctrine Test Program

National Research Council Canada - National Science Library

Hoover, J

1998-01-01

... in critical spaces or provide safe ingresslegress routes. This program sponsored six test series between January 1995 and August 1996 and made specific recommendations for the use of ventilation during submarine firefighting...

Maximizing the ExoEarth candidate yield from a future direct imaging mission

International Nuclear Information System (INIS)

Stark, Christopher C.; Roberge, Aki; Mandell, Avi; Robinson, Tyler D.

2014-01-01

ExoEarth yield is a critical science metric for future exoplanet imaging missions. Here we estimate exoEarth candidate yield using single visit completeness for a variety of mission design and astrophysical parameters. We review the methods used in previous yield calculations and show that the method choice can significantly impact yield estimates as well as how the yield responds to mission parameters. We introduce a method, called Altruistic Yield Optimization, that optimizes the target list and exposure times to maximize mission yield, adapts maximally to changes in mission parameters, and increases exoEarth candidate yield by up to 100% compared to previous methods. We use Altruistic Yield Optimization to estimate exoEarth candidate yield for a large suite of mission and astrophysical parameters using single visit completeness. We find that exoEarth candidate yield is most sensitive to telescope diameter, followed by coronagraph inner working angle, followed by coronagraph contrast, and finally coronagraph contrast noise floor. We find a surprisingly weak dependence of exoEarth candidate yield on exozodi level. Additionally, we provide a quantitative approach to defining a yield goal for future exoEarth-imaging missions.

Perspective on direct conversion

Energy Technology Data Exchange (ETDEWEB)

Lewis, W B

1963-10-15

The objective of direct conversion is high electrical output for minimum total cost, and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment, and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy, and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (auth)

Problems in the forecasting of solar particle events for manned missions

International Nuclear Information System (INIS)

Feynman, J.; Ruzmaikin, A.

1999-01-01

Manned spacecraft will require a much improved ability to forecast solar particle events. The lead time required will depend on the use to which the forecast is put. Here we discuss problems of forecasting with the lead times of hours to weeks. Such forecasts are needed for scheduling and carrying out activities. Our present capabilities with these lead times is extremely limited. To improve our capability we must develop an ability to predict fast coronal mass ejections (CMEs). It is not sufficient to observe that a CME has already taken place since by that time it is already too late to make predictions with these lead times. Both to learn how to predict CMEs and to carry out forecasts on time scales of several days to weeks, observations of the other side of the Sun are required. We describe a low-cost space mission of this type that would further the development of an hours-to-weeks forecast capability

Submarine landslide: A case study from the southwestern of Taiwan offshore

Science.gov (United States)

Hung, Y. H.; Dong, J. J.

2016-12-01

Based on the new multibeam bathymetric data and seismic reflection profiles of the southwestern Taiwan, more and more submarine landslides developed there have been being discovered nowadays. Palm Ridge, located between the boundary of the active and passive margins, is the place where a deformation front passes through. And previous studies suspected that there were old submarine landslides developed here. To learn whether there are old submarine landslides here, a further study is conducted with the collection and analysis of new high-resolution swath-bathymetry and seismic data. Firstly, based on the swath-bathymetry, the topography range of the landslide is mapped and interpreted with the three dimensional model. Then, according to the profile of the mapping, the extending of the sliding surface is predicted. And referred on the properties of soil in adjacent region, the engineering geologic models of the landslide before and after failure are proposed. Thirdly, through a detailed analysis of the seismic data of Taiwan in the past three decades, a magnitude of 7.7 MW is selected as the lower bound of earthquake for the analysis of the trigger of the submarine landslide. And based on the record of earthquakes with 8 MW in the world, some other earthquake magnitudes are also considered in this study. After applying them into STABL 5M, the failure process of the landslide is modeled with its possible deposited ranges being reached. Finally, the sub-bottom and seismic data are used to verify the rationality of the above results. Preliminary result shows that there were at least three landslides occurred in Palm Ridge. The first landslide is largest which covers the approximate range of the study area. The second one is developed in the margin area of the first one, which is resulted by the occurrence of the first one. The third event is caused by the further collapse of the first one due to the loose of its inner structure.

Estimation of submarine mass failure probability from a sequence of deposits with age dates

Science.gov (United States)

Geist, Eric L.; Chaytor, Jason D.; Parsons, Thomas E.; ten Brink, Uri S.

2013-01-01

The empirical probability of submarine mass failure is quantified from a sequence of dated mass-transport deposits. Several different techniques are described to estimate the parameters for a suite of candidate probability models. The techniques, previously developed for analyzing paleoseismic data, include maximum likelihood and Type II (Bayesian) maximum likelihood methods derived from renewal process theory and Monte Carlo methods. The estimated mean return time from these methods, unlike estimates from a simple arithmetic mean of the center age dates and standard likelihood methods, includes the effects of age-dating uncertainty and of open time intervals before the first and after the last event. The likelihood techniques are evaluated using Akaike’s Information Criterion (AIC) and Akaike’s Bayesian Information Criterion (ABIC) to select the optimal model. The techniques are applied to mass transport deposits recorded in two Integrated Ocean Drilling Program (IODP) drill sites located in the Ursa Basin, northern Gulf of Mexico. Dates of the deposits were constrained by regional bio- and magnetostratigraphy from a previous study. Results of the analysis indicate that submarine mass failures in this location occur primarily according to a Poisson process in which failures are independent and return times follow an exponential distribution. However, some of the model results suggest that submarine mass failures may occur quasiperiodically at one of the sites (U1324). The suite of techniques described in this study provides quantitative probability estimates of submarine mass failure occurrence, for any number of deposits and age uncertainty distributions.

On a directed tree problem motivated by a newly introduced graph product

Directory of Open Access Journals (Sweden)

Antoon H. Boode

2015-10-01

Full Text Available In this paper we introduce and study a directed tree problem motivated by a new graph product that we have recently introduced and analysed in two conference contributions in the context of periodic real-time processes. While the two conference papers were focussing more on the applications, here we mainly deal with the graph theoretical and computational complexity issues. We show that the directed tree problem is NP-complete and present and compare several heuristics for this problem.

Water quality, Multivariate statistical techniques, submarine out fall, spatial variation, temporal variation

International Nuclear Information System (INIS)

Garcia, Francisco; Palacio, Carlos; Garcia, Uriel

2012-01-01

Multivariate statistical techniques were used to investigate the temporal and spatial variations of water quality at the Santa Marta coastal area where a submarine out fall that discharges 1 m3/s of domestic wastewater is located. Two-way analysis of variance (ANOVA), cluster and principal component analysis and Krigging interpolation were considered for this report. Temporal variation showed two heterogeneous periods. From December to April, and July, where the concentration of the water quality parameters is higher; the rest of the year (May, June, August-November) were significantly lower. The spatial variation reported two areas where the water quality is different, this difference is related to the proximity to the submarine out fall discharge.

An IKBS approach to surveillance for naval nuclear submarine propulsion

International Nuclear Information System (INIS)

Cadas, C.N.; Bowskill, J.; Mayfield, T.; Clarke, J.C.

1995-01-01

This Paper describes work being carried out to develop an intelligent knowledge-based system (IKBS) for use in the surveillance of naval nuclear submarine propulsion plant. In recent years, modern process plants have increased automation and installed surveillance equipment while reducing the level of manpower operating and monitoring the plant. As a result, some of the local watchkeeping tasks have been transferred to control room operators, and the data reduction and warning filtering expertise inherent in local plant operators has been lost, while an additional workload has been placed upon operators. The surveillance systems installed to date have therefore been less usable than anticipated. The solution being achieved for submarine power plant is to introduce IKBS into surveillance to replace lost expertise and return to a situation in which operators receive small amounts of high quality information rather than large amounts of low quality information. (author)

A Baseline Air Quality Assessment Onboard a Victoria Class Submarine: HMCS Windsor

National Research Council Canada - National Science Library

Severs, Y. D

2006-01-01

.... This trial thus represents a baseline habitability evaluation of Canada's Victoria class submarines to confirm compliance with the current maximum permissible contaminant limits stipulated in the Air...

The brazilian nuclear submarine dossier: Navy's priority and its application

International Nuclear Information System (INIS)

Rosa, L.P.

1990-01-01

This work discusses the feasibility of the brazilian nuclear submarine. It is related to navy's remodeling and is considered as a priority. It would bring Brazil closer to developed countries. It considers the slip, itself, the weapon's system as well as the nuclear propulsion. (author)

Strengthening LLNL Missions through Laboratory Directed Research and Development in High Performance Computing

Energy Technology Data Exchange (ETDEWEB)

Willis, D. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-12-01

High performance computing (HPC) has been a defining strength of Lawrence Livermore National Laboratory (LLNL) since its founding. Livermore scientists have designed and used some of the world’s most powerful computers to drive breakthroughs in nearly every mission area. Today, the Laboratory is recognized as a world leader in the application of HPC to complex science, technology, and engineering challenges. Most importantly, HPC has been integral to the National Nuclear Security Administration’s (NNSA’s) Stockpile Stewardship Program—designed to ensure the safety, security, and reliability of our nuclear deterrent without nuclear testing. A critical factor behind Lawrence Livermore’s preeminence in HPC is the ongoing investments made by the Laboratory Directed Research and Development (LDRD) Program in cutting-edge concepts to enable efficient utilization of these powerful machines. Congress established the LDRD Program in 1991 to maintain the technical vitality of the Department of Energy (DOE) national laboratories. Since then, LDRD has been, and continues to be, an essential tool for exploring anticipated needs that lie beyond the planning horizon of our programs and for attracting the next generation of talented visionaries. Through LDRD, Livermore researchers can examine future challenges, propose and explore innovative solutions, and deliver creative approaches to support our missions. The present scientific and technical strengths of the Laboratory are, in large part, a product of past LDRD investments in HPC. Here, we provide seven examples of LDRD projects from the past decade that have played a critical role in building LLNL’s HPC, computer science, mathematics, and data science research capabilities, and describe how they have impacted LLNL’s mission.

Directed Bee Colony Optimization Algorithm to Solve the Nurse Rostering Problem.

Science.gov (United States)

Rajeswari, M; Amudhavel, J; Pothula, Sujatha; Dhavachelvan, P

2017-01-01

The Nurse Rostering Problem is an NP-hard combinatorial optimization, scheduling problem for assigning a set of nurses to shifts per day by considering both hard and soft constraints. A novel metaheuristic technique is required for solving Nurse Rostering Problem (NRP). This work proposes a metaheuristic technique called Directed Bee Colony Optimization Algorithm using the Modified Nelder-Mead Method for solving the NRP. To solve the NRP, the authors used a multiobjective mathematical programming model and proposed a methodology for the adaptation of a Multiobjective Directed Bee Colony Optimization (MODBCO). MODBCO is used successfully for solving the multiobjective problem of optimizing the scheduling problems. This MODBCO is an integration of deterministic local search, multiagent particle system environment, and honey bee decision-making process. The performance of the algorithm is assessed using the standard dataset INRC2010, and it reflects many real-world cases which vary in size and complexity. The experimental analysis uses statistical tools to show the uniqueness of the algorithm on assessment criteria.

Comparative safety assessment of surface versus submarine plutonium shipments

International Nuclear Information System (INIS)

Knepper, D.S.; Feltus, M.A.

1993-01-01

The recent shipment of plutonium from France to Japan aboard the freighter Akatsuki Maru touched off protests from environmental and antinuclear organizations. These protests arose from the fear of an accidental sinking of the vessel that would release its cargo to the sea, as well as the threat of a terrorist nation highjacking the ship for its cargo to produce atomic weapons. The sinking of a merchant ship is not uncommon, as illustrated by the famous losses of the tankers Amoco Cadiz and Exxon Valdez. The highjacking of a lightly armed freighter such as the Akatsuki Maru is possible and would not be unduly difficult for a well-equipped terrorist nation. The combined threats of weapons proliferation and environmental damage arising from the diversion or destruction of a sea vessel carrying plutonium will continue to abound as the reprocessing of spent nuclear fuel increases. An alternate method for the transportation with reduced risks of both diversion and destruction needs to be developed. The shipment aboard the Akatsuki Maru was originally proposed to be flown from France to Japan over the continental United States. This proposal was rejected by the Reagan administration in 1988. A third alternative to the current ideas of air transport and surface transport is subsurface transport. This research project investigates the transportation of plutonium by submarine and compares it to the current method of transportation by freighter. This analysis involves a study of the military threat to a submarine by a terrorist nation and comparable threat to a surface vessel. To study the nonmilitary aspects of plutonium shipping, a fault-tree evaluation is performed for transportation by submarine and compared with the current risk analysis performed for surface vessels

Constraining the sedimentology and stratigraphy of submarine intraslope lobe deposits using exhumed examples from the Karoo Basin, South Africa

NARCIS (Netherlands)

Spychala, Y. T.; Hodgson, D. M.; Flint, S. S.; Mountney, N. P.

2015-01-01

Intraslope lobe deposits provide a process record of the infill of accommodation on submarine slopes and their recognition enables the accurate reconstruction of the stratigraphic evolution of submarine slope systems. Extensive exposures of discrete sand-prone packages in Units D/E and E, Fort Brown

Sedimentary characteristics of samples collected from some submarine canyons

NARCIS (Netherlands)

Bouma, Arnold H.

Oriented rectangular cores of 20.3 × 30.5 cm and 45.7 cm high have been collected in a number of submarine canyons off southern California (U.S.A.) and off the southern tip of Baja California (Mexico) for a detailed study of their sedimentary structures. By applying several methods, mainly X-ray

Large submarine sand-rubble flow on Kilauea volcano, Hawaii

Energy Technology Data Exchange (ETDEWEB)

Fornari, D J [Columbia Univ., Palisades, NY; Moore, J G; Calk, L

1979-05-01

Papa'u seamount on the south submarine slope of Kilauea volcano is a large landslide about 19 km long, 6 km wide, and up to 1 km thick with a volume of about 39 km/sup 3/. Dredge hauls, remote camera photographs, and submersible observations indicate that it is composed primarily of unconsolidated angular glassy basalt sand with scattered basalt blocks up to 1 m in size; no lava flows were seen. Sulfur contents of basalt glass from several places on the sand-rubble flow and nearby areas are low (< 240 ppm), indicating that the clastic basaltic material was all erupted on land. The Papa'u sandrubble flow was emplaced during a single flow event fed from a large near-shore bank of clastic basaltic material which in turn was formed as lava flows from the summit area of Kilauea volcano disintegrated when they entered the sea. The current eruptive output of the volcano suggests that the material in the submarine sand-rubble flow represents about 6000 years of accumulation, and that the flow event occurred several thousand years ago.

Simulation of Wave-Plus-Current Scour beneath Submarine Pipelines

DEFF Research Database (Denmark)

Eltard-Larsen, Bjarke; Fuhrman, David R.; Sumer, B. Mutlu

2016-01-01

A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed and suspen......A fully coupled hydrodynamic and morphologic numerical model was utilized for the simulation of wave-plus-current scour beneath submarine pipelines. The model was based on incompressible Reynolds-averaged Navier–Stokes equations, coupled with k-ω turbulence closure, with additional bed...... and suspended load descriptions forming the basis for seabed morphology. The model was successfully validated against experimental measurements involving scour development and eventual equilibrium in pure-current flows over a range of Shields parameters characteristic of both clear-water and live-bed regimes....... This validation complements previously demonstrated accuracy for the same model in simulating pipeline scour processes in pure-wave environments. The model was subsequently utilized to simulate combined wave-plus-current scour over a wide range of combined Keulegan–Carpenter numbers and relative current strengths...

Autonomous long-term gamma-spectrometric monitoring of submarine groundwater discharge trends in Hawaii

International Nuclear Information System (INIS)

Dulai, Henrietta; Waters, Ch.A.; Kennedy, Joseph; Kamenik, Jan; Academy of Sciences of the Czech Republic, Rez; Babinec, James; Jolly, James; Williamson, Mario

2016-01-01

We developed a fully autonomous underwater gamma-spectrometer for long-term coastal submarine groundwater discharge (SGD) monitoring. The instrument represents a significant improvement over previous submarine gamma-spectrometers in that it is very robust, has high sensitivity allowing high temporal resolution, and is completely autonomous. Here we describe the technical parameters of the new instrument as well as data collected over its 9-month deployment in Kiholo Bay, HI, USA. We also present methods to convert the measured activities to SGD rates. In Kiholo Bay, the derived SGD matched previous estimates but in addition it revealed previously undocumented short- and long-term patterns in SGD. (author)

Flow dynamics around downwelling submarine canyons

Directory of Open Access Journals (Sweden)

J. M. Spurgin

2014-10-01

Full Text Available Flow dynamics around a downwelling submarine canyon were analysed with the Massachusetts Institute of Technology general circulation model. Blanes Canyon (northwestern Mediterranean was used for topographic and initial forcing conditions. Fourteen scenarios were modelled with varying forcing conditions. Rossby and Burger numbers were used to determine the significance of Coriolis acceleration and stratification (respectively and their impacts on flow dynamics. A new non-dimensional parameter (χ was introduced to determine the significance of vertical variations in stratification. Some simulations do see brief periods of upwards displacement of water during the 10-day model period; however, the presence of the submarine canyon is found to enhance downwards advection of density in all model scenarios. High Burger numbers lead to negative vorticity and a trapped anticyclonic eddy within the canyon, as well as an increased density anomaly. Low Burger numbers lead to positive vorticity, cyclonic circulation, and weaker density anomalies. Vertical variations in stratification affect zonal jet placement. Under the same forcing conditions, the zonal jet is pushed offshore in more uniformly stratified domains. The offshore jet location generates upwards density advection away from the canyon, while onshore jets generate downwards density advection everywhere within the model domain. Increasing Rossby values across the canyon axis, as well as decreasing Burger values, increase negative vertical flux at shelf break depth (150 m. Increasing Rossby numbers lead to stronger downwards advection of a passive tracer (nitrate, as well as stronger vorticity within the canyon. Results from previous studies are explained within this new dynamic framework.

International year of planet earth 7. Oceans, submarine land-slides and consequent tsunamis in Canada

Science.gov (United States)

Mosher, D.C.

2009-01-01

Canada has the longest coastline and largest continental margin of any nation in the World. As a result, it is more likely than other nations to experience marine geohazards such as submarine landslides and consequent tsunamis. Coastal landslides represent a specific threat because of their possible proximity to societal infrastructure and high tsunami potential; they occur without warning and with little time lag between failure and tsunami impact. Continental margin landslides are common in the geologic record but rare on human timescales. Some ancient submarine landslides are massive but more recent events indicate that even relatively small slides on continental margins can generate devastating tsunamis. Tsunami impact can occur hundreds of km away from the source event, and with less than 2 hours warning. Identification of high-potential submarine landslide regions, combined with an understanding of landslide and tsunami processes and sophisticated tsunami propagation models, are required to identify areas at high risk of impact.

Design and analysis of submarine radome

Science.gov (United States)

Sandeep, C. Satya; Prasad, U. Shiva; Suresh, R.; Rathan, A.; Sravanthi, G.; Govardhan, D.

2017-07-01

Radomes are the electromagnetic windows that protect microwave sub-systems from the environmental effects. The major requirement of radome is its transparency to microwaves and for most of the cases mechanical properties are also equally important. Radome for underwater applications has to withstand high water pressure of the order of 45 bars. Composite materials owing to their high strength to weight ratio, high stiffness and better corrosion resistance are potential source for under water applications. The concept of 'tailoring' the material properties to suit the radome is obtained by selecting proper reinforcement, resin matrix and their compositions. The mechanical properties of composite material, evaluated by testing specimens as per ASTM standards, are utilized in designing the radome. The modulus properties calculated using classical theories of composite materials and compared with test results. ANSYS a Finite Element software package used to analyse the problem. As the cross sectional thickness of radome varies, the complexity in fabrication is overcome by adopting matched die techniques. The radome design and finite element analysis validation concluded by conducting the pressure test on radome. On the design a modal analysis is also carried to check for the natural frequency, So that resonance does not occur if the natural frequency of the radome coincides with the excitation frequency of the submarine Clinical information system (CIS) for UNRWA is a computerized distributed application that used in clinics which follows the United Nations Relief and Works Agency (UNRWA) to manage the clinical requirements and services.

Variational approach to direct and inverse problems of atmospheric pollution studies

Science.gov (United States)

Penenko, Vladimir; Tsvetova, Elena; Penenko, Alexey

2016-04-01

We present the development of a variational approach for solving interrelated problems of atmospheric hydrodynamics and chemistry concerning air pollution transport and transformations. The proposed approach allows us to carry out complex studies of different-scale physical and chemical processes using the methods of direct and inverse modeling [1-3]. We formulate the problems of risk/vulnerability and uncertainty assessment, sensitivity studies, variational data assimilation procedures [4], etc. A computational technology of constructing consistent mathematical models and methods of their numerical implementation is based on the variational principle in the weak constraint formulation specifically designed to account for uncertainties in models and observations. Algorithms for direct and inverse modeling are designed with the use of global and local adjoint problems. Implementing the idea of adjoint integrating factors provides unconditionally monotone and stable discrete-analytic approximations for convection-diffusion-reaction problems [5,6]. The general framework is applied to the direct and inverse problems for the models of transport and transformation of pollutants in Siberian and Arctic regions. The work has been partially supported by the RFBR grant 14-01-00125 and RAS Presidium Program I.33P. References: 1. V. Penenko, A.Baklanov, E. Tsvetova and A. Mahura . Direct and inverse problems in a variational concept of environmental modeling //Pure and Applied Geoph.(2012) v.169: 447-465. 2. V. V. Penenko, E. A. Tsvetova, and A. V. Penenko Development of variational approach for direct and inverse problems of atmospheric hydrodynamics and chemistry, Izvestiya, Atmospheric and Oceanic Physics, 2015, Vol. 51, No. 3, p. 311-319, DOI: 10.1134/S0001433815030093. 3. V.V. Penenko, E.A. Tsvetova, A.V. Penenko. Methods based on the joint use of models and observational data in the framework of variational approach to forecasting weather and atmospheric composition

The Role of the Submarine Channel Pernambuco in the Brazilian Continental Margin East

International Nuclear Information System (INIS)

Torres, L.; Villena, H.

2010-01-01

The Brazilian Continental Margin, which coastline measures more than 8,500km gives to Brazil continental dimensions. This huge region is conditioned by the action of process such as, sedimentals, tectonics, geomorphological and climatical, as example, which direct or in conjunction with other ones, since of continental break up between South America and Africa are going on and may be responsible for the current morphology of the margin. In accordance with this point of view, the Oriental part of the Brazilian Continental Margin, presents characteristics of a passive margin and fisiographically ''starved'', in which the continental break occur no more than 100km from de coastline and the sedimentary coverage is mainly carbonatic. The continental slope does not present great extension if compared with other parts of the Brazilian Margin and sharp gradient. The remark presence of the continental plateaus (Rio Grande Plateau and Pernambuco Plateau), which link with the continental rise and additionally the Paraiba, Pernambuco e Bahia seamounts, are the majors features in the morphology of the region between the slope and the continental rise. This paper will concentrate its focus on Bahia Seamount, with emphasis in the mainly erosive feature which cut transversally the seamounts, named Pernambuco Submarine Channel. It will be employed bathymetric multibeam and seismic data carried out by the Brazilian Continental Shelf Project (LEPLAC) in the current year and pieces of information from bibliographic researches in order to present a discussion by the hole of the Pernambuco Submarine Channel in the Occidental region of the Brazilian Continental Margin

Discovery and characterization of submarine groundwater discharge in the Siberian Arctic seas: A case study in Buor-Khaya Gulf, Laptev Sea

OpenAIRE

Charkin, Alexander N.; Rutgers van der Loeff, Michiel; Shakhova, Natalia E.; Gustafsson, Örjan; Dudarev, Oleg V.; Cherepnev, Maxim S.; Salyuk, Anatoly N.; Koshurnikov, Andrey V.; Spivak, Eduard A.; Gunar, Alexey Y.; Semiletov, Igor P.

2017-01-01

It has been suggested that increasing freshwater discharge to the Arctic Ocean may also occur as submarine groundwater discharge (SGD), yet there are no direct observations of this phenomenon in the Arctic shelf seas. This study tests the hypothesis that SGD does exist in the Siberian-Arctic shelf seas but its dynamics may be largely controlled by complicated geocryological conditions such as permafrost. The field-observational approach in the southeast Laptev Sea used a combination of hydrol...

Hydroids from submarine cliffs near Arthur Harbour, Palmer Archipelago, Antarctica

NARCIS (Netherlands)

Vervoort, W.

1972-01-01

At the instigation of Dr. Joel W. Hedgpeth, Resident Director, Marine Science Center, Oregon State University, Newport, Oregon, U.S.A., I studied samples of hydroids, collected by Dr. John C. McCain and Dr. William E. Stout from submarine cliffs in the region around Palmer Station, Antarctica. The

Serreta Submarine Eruption 1998-2001, Azores: a new compositional end-member?

Science.gov (United States)

Filipa Marques, Ana; Hamelin, Cédric; Madureira, Pedro; Rosa, Carlos; Silva, Pedro; Relvas, Jorge; Lourenço, Nuno; Conceição, Patrícia; Barriga, Fernando

2014-05-01

The Azores platform, where the Eurasian, Nubian and American plates meet, comprises nine volcanic islands extending to both sides of the Mid-Atlantic Ridge (MAR). East of the MAR, the plate boundary between Eurasian and Nubian plates is defined by the Terceira Rift, interpreted as an intra-oceanic spreading system where the Islands of S. Miguel, Terceira and Graciosa emerge as well and the submarine D.João de Castro Bank, separated by deep avolcanic zones [1, 2]. Submarine and subaerial lavas from the Terceira Rift are characterized by small-scale elemental and isotopic variations, and several distinct compositional end-members have been identified [2,3] supporting the concept of significant mantle source heterogeneity. A recent submarine eruption (1998-2001) occurred ~4-5 NM WNW of Terceira Island, at the Serreta Ridge where lava balloons were observed floating at the surface [4]. In 2008, an oceanographic cruise was conducted to the Serreta ridge to investigate the site of the 1998-2001 eruption, map the seafloor, identify vent location, and characterize possible products of eruption [5]. An ROV from the EMEPC (Task Group for the Extension of the Continental Shelf) was used in this survey providing high-definition video footage and fresh lava samples. Three survey ROV dives (D15, D16, D17) were made on the Serreta ridge. D15 and D17 dives were located on the southern wall of the crater, whereas D16 explored the central and northern areas of the crater floor. Sr-Nd-Pb isotope compositions of representative samples from the Serreta submarine ridge are presented for the first time. On the 208Pb/204Pb vs. 206Pb/204Pb diagram Serreta samples plot on a linear array with the remaining Terceira rift samples. However, these results show that Serreta submarine volcanics lay on the most depleted end of the Terceira Rift array. Radiogenic isotopes also show that samples from the central and northern wall of the crater are distinct from the younger southern wall sector

Assessment of Fire Growth and Mitigation in Submarine Plastic Waste Stowage Compartments

National Research Council Canada - National Science Library

Ndubizu, Chuka

2000-01-01

This report presents the results of tests to assess the fire growth characteristics and the ease of fire control in the proposed Virginia-class and the Ohio-class submarine plastic waste stowage compartments...

A fast direct solver for boundary value problems on locally perturbed geometries

Science.gov (United States)

Zhang, Yabin; Gillman, Adrianna

2018-03-01

Many applications including optimal design and adaptive discretization techniques involve solving several boundary value problems on geometries that are local perturbations of an original geometry. This manuscript presents a fast direct solver for boundary value problems that are recast as boundary integral equations. The idea is to write the discretized boundary integral equation on a new geometry as a low rank update to the discretized problem on the original geometry. Using the Sherman-Morrison formula, the inverse can be expressed in terms of the inverse of the original system applied to the low rank factors and the right hand side. Numerical results illustrate for problems where perturbation is localized the fast direct solver is three times faster than building a new solver from scratch.

Hydrate-bearing Submarine Landslides in the Orca Basin, Gulf of Mexico

Science.gov (United States)

Sawyer, D.; Mason, A.; Cook, A.; Portnov, A.; Hillman, J.

2017-12-01

The co-occurrence of submarine landslides and hydrate-bearing sediment suggests that hydrates may play a role in landslide triggering and/or the mobility and dynamic characteristics of the submarine landslide. In turn, the removal of large sections of seafloor perturbs the hydrate stability field by removing overburden pressure and disturbing the temperature field. These potential hydrate-landslide feedbacks are not well understood. Here we combine three-dimensional seismic and petrophysical logs to characterize the deposits of submarine landslides that failed from hydrate-bearing sediments in the Orca Basin in the northern Gulf of Mexico. The Orca Basin contains a regionally mappable bottom simulating reflector, hydrate saturations within sands and muds, as well as numerous landslides. In addition, the Orca Basin features a well-known 123 km2 anoxic hypersaline brine pool that is actively being fed by outcropping salt. Lying at the bottom of the brine pool are deposits of submarine landslides. Slope instability in the Orca Basin is likely associated with near-seafloor salt tectonics. The most prominent landslide scar observable on the seafloor has a correlative deposit that now lies at the bottom of the brine pool 11.6 km away. The headwall is amphitheater-shaped with an average height of 80 meters and with only a minor amount of rubble remaining near the headwall. A total of 8.7 km3 of material was removed and deposited between the lower slopes of the basin and the base of the brine pool. Around the perimeter of the landslide headwall, two industry wells were drilled and well logs show elevated resistivity that are likely caused by gas hydrate. The slide deposits have a chaotic seismic facies with large entrained blocks and the headwall area does not retain much original material, which together suggests a relatively mobile style of landslide and therefore may have generated a wave upon impacting the brine pool. Such a slide-induced wave may have sloshed

Multi-frequency direct sampling method in inverse scattering problem

Science.gov (United States)

Kang, Sangwoo; Lambert, Marc; Park, Won-Kwang

2017-10-01

We consider the direct sampling method (DSM) for the two-dimensional inverse scattering problem. Although DSM is fast, stable, and effective, some phenomena remain unexplained by the existing results. We show that the imaging function of the direct sampling method can be expressed by a Bessel function of order zero. We also clarify the previously unexplained imaging phenomena and suggest multi-frequency DSM to overcome traditional DSM. Our method is evaluated in simulation studies using both single and multiple frequencies.

The Exo-S probe class starshade mission

Science.gov (United States)

Seager, Sara; Turnbull, Margaret; Sparks, William; Thomson, Mark; Shaklan, Stuart B.; Roberge, Aki; Kuchner, Marc; Kasdin, N. Jeremy; Domagal-Goldman, Shawn; Cash, Webster; Warfield, Keith; Lisman, Doug; Scharf, Dan; Webb, David; Trabert, Rachel; Martin, Stefan; Cady, Eric; Heneghan, Cate

2015-09-01

Exo-S is a direct imaging space-based mission to discover and characterize exoplanets. With its modest size, Exo-S bridges the gap between census missions like Kepler and a future space-based flagship direct imaging exoplanet mission. With the ability to reach down to Earth-size planets in the habitable zones of nearly two dozen nearby stars, Exo-S is a powerful first step in the search for and identification of Earth-like planets. Compelling science can be returned at the same time as the technological and scientific framework is developed for a larger flagship mission. The Exo-S Science and Technology Definition Team studied two viable starshade-telescope missions for exoplanet direct imaging, targeted to the $1B cost guideline. The first Exo-S mission concept is a starshade and telescope system dedicated to each other for the sole purpose of direct imaging for exoplanets (The "Starshade Dedicated Mission"). The starshade and commercial, 1.1-m diameter telescope co-launch, sharing the same low-cost launch vehicle, conserving cost. The Dedicated mission orbits in a heliocentric, Earth leading, Earth-drift away orbit. The telescope has a conventional instrument package that includes the planet camera, a basic spectrometer, and a guide camera. The second Exo-S mission concept is a starshade that launches separately to rendezvous with an existing on-orbit space telescope (the "Starshade Rendezvous Mission"). The existing telescope adopted for the study is the WFIRST-AFTA (Wide-Field Infrared Survey Telescope Astrophysics Focused Telescope Asset). The WFIRST-AFTA 2.4-m telescope is assumed to have previously launched to a Halo orbit about the Earth-Sun L2 point, away from the gravity gradient of Earth orbit which is unsuitable for formation flying of the starshade and telescope. The impact on WFIRST-AFTA for starshade readiness is minimized; the existing coronagraph instrument performs as the starshade science instrument, while formation guidance is handled by the

Noble gas systematics of submarine alkalic lavas near the Hawaiian hotspot

NARCIS (Netherlands)

Hanyu, T.; Clague, D.A.; Kaneoka, I.; Dunai, T.J.; Davies, G.R.

2005-01-01

Noble gas isotopic ratios were determined for submarine alkalic volcanic rocks distributed around the Hawaiian islands to constrain the origin of such alkalic volcanism and hence understand the details of mantle upwelling beneath Hawaii. Samples were collected by dredging or using submersibles from

Russian nuclear submarine elimination 2001 - 2011 by the international community - 59041

International Nuclear Information System (INIS)

Washer, Michael; Heyes, Alan

2012-01-01

Document available in abstract form only. Full text of publication follows: Following the 911 attack on the USA in 2001 the international community under Canada's G8 leadership established a $20 billion Global Partnership initiative to collaboratively address threats to global security posed by the proliferation and potential terrorist use of Weapons and Materials of Mass Destruction (WMMD) and related materials and knowledge. As an integral component of this initiative the international community agreed to assist Russia in advancing the elimination of its Cold War legacy of nearly 200 nuclear powered submarines left over from the collapse of the Soviet Union. This presentation presents an overview of the 10 years work that has now entirely eliminated that submarine legacy. The scale and complexity of the challenge along with each country's contribution and approach is discussed along with key success factors and unique solutions adopted. (authors)

Measurement of submarine groundwater discharge using diverse methods in Coleroon Estuary, Tamil Nadu, India

Science.gov (United States)

Prakash, R.; Srinivasamoorthy, K.; Gopinath, S.; Saravanan, K.

2018-03-01

Submarine groundwater discharge (SGD) is described as submarine inflow of fresh and brackish groundwater from land into the sea. The release of sewages from point and non-point source pollutants from industries, agricultural and domestic activities gets discharged through groundwater to ocean creating natural disparity like decreasing flora fauna and phytoplankton blooms. Hence, to quantify fluxes of SGD in coastal regions is important. Quantification of SGD was attempted in Coleroon estuary, India, using three dissimilar methods like water budget, Darcy law and manual seepage meter. Three seepage meters were installed at two prominent litho units (alluvium and fluvio marine) at a distance of (0-14.7 km) away from Bay of Bengal. The water budget and Darcy law-quantified submarine seepage at a rate of 6.9 × 106 and 3.2 × 103 to 308.3 × 103 m3 year-1, respectively, and the seepage meter quantified seepage rate of 0.7024 m h-1 at an average. Larger seepage variations were isolated from three different techniques and the seepage rates were found to be influenced by hydrogeological characteristics of the litho units and distance from the coast.

Marine environmental radioactivity surveys at nuclear submarine berths 2001

International Nuclear Information System (INIS)

Cowling, E.; Ball, R.; Simpson, C.

2002-01-01

This report presents the results of the marine environmental radioactivity monitoring surveys of intertidal and underwater areas around nuclear submarine berths which were carried out by DRPS during 2001. Also included are results of smaller scale intertidal surveys carried out by local staff but co-ordinated by DRPS. Cobalt-60, the nuclide of major importance in naval discharges, was detected in a number of samples but in many cases was attributable to discharges by other operators. Concentrations in any case were found to be low, and at no survey location did the calculated annual radiation dose commitment to the most exposed members of the general public due to the presence of cobalt-60 exceed 1% of the ICRP principal dose limit for members of the public (1000μSv). These results are consistent with those obtained in the independent monitoring programmes as reported in the Radioactivity in Food and the Environment (RIFE) annual reports. It is concluded that existing discharge arrangements are providing effective control over environmental levels of radioactivity, and that there has been no radiological hazard to any member of the general public during 2001 from the operation of nuclear powered submarines. (author)

The pumice raft-forming 2012 Havre submarine eruption was effusive

Science.gov (United States)

Manga, Michael; Fauria, Kristen E.; Lin, Christina; Mitchell, Samuel J.; Jones, Meghan; Conway, Chris E.; Degruyter, Wim; Hosseini, Behnaz; Carey, Rebecca; Cahalan, Ryan; Houghton, Bruce F.; White, James D. L.; Jutzeler, Martin; Soule, S. Adam; Tani, Kenichiro

2018-05-01

A long-standing conceptual model for deep submarine eruptions is that high hydrostatic pressure hinders degassing and acceleration, and suppresses magma fragmentation. The 2012 submarine rhyolite eruption of Havre volcano in the Kermadec arc provided constraints on critical parameters to quantitatively test these concepts. This eruption produced a >1 km3 raft of floating pumice and a 0.1 km3 field of giant (>1 m) pumice clasts distributed down-current from the vent. We address the mechanism of creating these clasts using a model for magma ascent in a conduit. We use water ingestion experiments to address why some clasts float and others sink. We show that at the eruption depth of 900 m, the melt retained enough dissolved water, and hence had a low enough viscosity, that strain-rates were too low to cause brittle fragmentation in the conduit, despite mass discharge rates similar to Plinian eruptions on land. There was still, however, enough exsolved vapor at the vent depth to make the magma buoyant relative to seawater. Buoyant magma was thus extruded into the ocean where it rose, quenched, and fragmented to produce clasts up to several meters in diameter. We show that these large clasts would have floated to the sea surface within minutes, where air could enter pore space, and the fate of clasts is then controlled by the ability to trap gas within their pore space. We show that clasts from the raft retain enough gas to remain afloat whereas fragments from giant pumice collected from the seafloor ingest more water and sink. The pumice raft and the giant pumice seafloor deposit were thus produced during a clast-generating effusive submarine eruption, where fragmentation occurred above the vent, and the subsequent fate of clasts was controlled by their ability to ingest water.

Determination of diffusion parameters using radioactive tracers, aiming at a project of a submarine sewage outfall

International Nuclear Information System (INIS)

Santos, J.L. dos.

1979-01-01

Radioactive tracers technology is applied to pollutant dispersion studies in water bodies, for the project of submarine sewage outfall. The models proposed by Hansen/Harremoes and Okubo, respectively, for the prediction of physical dilution rates and determination of turbulent diffusion laws, are discussed. The methodology for field work as well as data processing is described. The results from field investigations carried out in Brazilian litoral waters for submarine release of sewage in Santos - Sao Vicente, Guaruja and Maceio, are presented and commented. (Author) [pt

The Thermal Regime Around Buried Submarine High-Voltage Cables

Science.gov (United States)

Emeana, C. J.; Dix, J.; Henstock, T.; Gernon, T.; Thompson, C.; Pilgrim, J.

2015-12-01

The expansion of offshore renewable energy infrastructure and the desire for "trans-continental shelf" power transmission, all require the use of submarine High Voltage (HV) cables. These cables have maximum operating surface temperatures of up to 70oC and are typically buried at depths of 1-2 m beneath the seabed, within the wide range of substrates found on the continental shelf. However, the thermal properties of near surface shelf sediments are poorly understood and this increases the uncertainty in determining the required cable current ratings, cable reliability and the potential effects on the sedimentary environments. We present temperature measurements from a 2D laboratory experiment, designed to represent a buried, submarine HV cable. We used a large (2.5 m-high) tank, filled with water-saturated ballotini and instrumented with 120 thermocouples, which measured the time-dependent 2D temperature distributions around the heat source. The experiments use a buried heat source to represent a series of realistic cable surface temperatures with the aim for identifying the thermal regimes generated within typical non-cohesive shelf sediments: coarse silt, fine sand and very coarse sand. The steady state heat flow regimes, and normalised and radial temperature distributions were assessed. Our results show that at temperatures up to 60°C above ambient, the thermal regimes are conductive for the coarse silt sediments and convective for the very coarse sand sediments even at 7°C above ambient. However, the heat flow pattern through the fine sand sediment shows a transition from conductive to convective heat flow at a temperature of approximately 20°C above ambient. These findings offer an important new understanding of the thermal regimes associated with submarine HV cables buried in different substrates and has huge impacts on cable ratings as the IEC 60287 standard only considers conductive heat flow as well as other potential near surface impacts.

A new model for turbidity current behavior based on integration of flow monitoring and precision coring in a submarine canyon

Science.gov (United States)

Symons, William O.; Sumner, Esther J.; Paull, Charles K.; Cartigny, Matthieu J.B.; Xu, Jingping; Maier, Katherine L.; Lorenson, Thomas; Talling, Peter J.

2017-01-01

Submarine turbidity currents create some of the largest sediment accumulations on Earth, yet there are few direct measurements of these flows. Instead, most of our understanding of turbidity currents results from analyzing their deposits in the sedimentary record. However, the lack of direct flow measurements means that there is considerable debate regarding how to interpret flow properties from ancient deposits. This novel study combines detailed flow monitoring with unusually precisely located cores at different heights, and multiple locations, within the Monterey submarine canyon, offshore California, USA. Dating demonstrates that the cores include the time interval that flows were monitored in the canyon, albeit individual layers cannot be tied to specific flows. There is good correlation between grain sizes collected by traps within the flow and grain sizes measured in cores from similar heights on the canyon walls. Synthesis of flow and deposit data suggests that turbidity currents sourced from the upper reaches of Monterey Canyon comprise three flow phases. Initially, a thin (38–50 m) powerful flow in the upper canyon can transport, tilt, and break the most proximal moorings and deposit chaotic sands and gravel on the canyon floor. The initially thin flow front then thickens and deposits interbedded sands and silty muds on the canyon walls as much as 62 m above the canyon floor. Finally, the flow thickens along its length, thus lofting silty mud and depositing it at greater altitudes than the previous deposits and in excess of 70 m altitude.

Direct and inverse source problems for a space fractional advection dispersion equation

KAUST Repository

Aldoghaither, Abeer; Laleg-Kirati, Taous-Meriem; Liu, Da Yan

2016-01-01

In this paper, direct and inverse problems for a space fractional advection dispersion equation on a finite domain are studied. The inverse problem consists in determining the source term from final observations. We first derive the analytic

Use of an UROV to develop 3-D optical models of submarine environments

Science.gov (United States)

Null, W. D.; Landry, B. J.

2017-12-01

The ability to rapidly obtain high-fidelity bathymetry is crucial for a broad range of engineering, scientific, and defense applications ranging from bridge scour, bedform morphodynamics, and coral reef health to unexploded ordnance detection and monitoring. The present work introduces the use of an Underwater Remotely Operated Vehicle (UROV) to develop 3-D optical models of submarine environments. The UROV used a Raspberry Pi camera mounted to a small servo which allowed for pitch control. Prior to video data collection, in situ camera calibration was conducted with the system. Multiple image frames were extracted from the underwater video for 3D reconstruction using Structure from Motion (SFM). This system provides a simple and cost effective solution to obtaining detailed bathymetry in optically clear submarine environments.

Method and apparatus for disposing a radioactive waste container to submarine bottom

International Nuclear Information System (INIS)

Shibata, Kiyoshi; Yoshida, Shoichi.

1980-01-01

Purpose: To completely eliminate a danger occurred by the rolling of a hull in the ocean in a method and apparatus for disposing radioactive waste container to submarine bottom by independently handling the radioactive waste containers when loading the container in a compartment carried on a barge and sinking the containers together with the compartment to the submarine bottom at its disposing time. Method: Radioactive waste containers are carried into a compartment loaded on a barge floating completely, and the barge is then applied with external force thereto by a ship or the like and sailed to the marine disposal area. Then, water is filled in the ballast tank of the barge to submerge the barge, the compartment is floated and separated from the containers, and water is charged into the compartment to sink the compartment. (Aizawa, K.)

Satellite-derived submarine melt rates and mass balance (2011-2015) for Greenland's largest remaining ice tongues

Science.gov (United States)

Wilson, Nat; Straneo, Fiammetta; Heimbach, Patrick

2017-12-01

Ice-shelf-like floating extensions at the termini of Greenland glaciers are undergoing rapid changes with potential implications for the stability of upstream glaciers and the ice sheet as a whole. While submarine melting is recognized as a major contributor to mass loss, the spatial distribution of submarine melting and its contribution to the total mass balance of these floating extensions is incompletely known and understood. Here, we use high-resolution WorldView satellite imagery collected between 2011 and 2015 to infer the magnitude and spatial variability of melt rates under Greenland's largest remaining ice tongues - Nioghalvfjerdsbræ (79 North Glacier, 79N), Ryder Glacier (RG), and Petermann Glacier (PG). Submarine melt rates under the ice tongues vary considerably, exceeding 50 m a-1 near the grounding zone and decaying rapidly downstream. Channels, likely originating from upstream subglacial channels, give rise to large melt variations across the ice tongues. We compare the total melt rates to the influx of ice to the ice tongue to assess their contribution to the current mass balance. At Petermann Glacier and Ryder Glacier, we find that the combined submarine and aerial melt approximately balances the ice flux from the grounded ice sheet. At Nioghalvfjerdsbræ the total melt flux (14.2 ± 0.96 km3 a-1 w.e., water equivalent) exceeds the inflow of ice (10.2 ± 0.59 km3 a-1 w.e.), indicating present thinning of the ice tongue.

France and nuclear proliferation: the new generation of nuclear submarines

International Nuclear Information System (INIS)

Barrillot, B.

2001-01-01

Ten years after the end of the 'cold war' the French government has pursued its national defense program with the construction of a new generation of nuclear submarines with new type of missiles and nuclear heads. This book analyzes the possible solutions for a step by step elimination of nuclear weapons from the French weapons stock. (J.S.)

Using Google Earth for Submarine Operations at Pavilion Lake

Science.gov (United States)

Deans, M. C.; Lees, D. S.; Fong, T.; Lim, D. S.

2009-12-01

During the July 2009 Pavilion Lake field test, we supported submarine "flight" operations using Google Earth. The Intelligent Robotics Group at NASA Ames has experience with ground data systems for NASA missions, earth analog field tests, disaster response, and the Gigapan camera system. Leveraging this expertise and existing software, we put together a set of tools to support sub tracking and mapping, called the "Surface Data System." This system supports flight planning, real time flight operations, and post-flight analysis. For planning, we make overlays of the regional bedrock geology, sonar bathymetry, and sonar backscatter maps that show geology, depth, and structure of the bottom. Placemarks show the mooring locations for start and end points. Flight plans are shown as polylines with icons for waypoints. Flight tracks and imagery from previous field seasons are embedded in the map for planning follow-on activities. These data provide context for flight planning. During flights, sub position is updated every 5 seconds from the nav computer on the chase boat. We periodically update tracking KML files and refresh them with network links. A sub icon shows current location of the sub. A compass rose shows bearings to indicate heading to the next waypoint. A "Science Stenographer" listens on the voice loop and transcribes significant observations in real time. Observations called up to the surface immediately appear on the map as icons with date, time, position, and what was said. After each flight, the science back room immediately has the flight track and georeferenced notes from the pilots. We add additional information in post-processing. The submarines record video continuously, with "event" timestamps marked by the pilot. We cross-correlate the event timestamps with position logs to geolocate events and put a preview image and compressed video clip into the map. Animated flight tracks are also generated, showing timestamped position and providing timelapse

Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

Directory of Open Access Journals (Sweden)

Minghua Xu

2014-01-01

Full Text Available We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has many applications. For solving this class of matrix optimization problems, many methods have been proposed in the literature. The proximal alternating direction method is one of those methods which can be easily applied to solve these matrix optimization problems. Generally, the proximal parameters of the proximal alternating direction method are greater than zero. In this paper, we conclude that the restriction on the proximal parameters can be relaxed for solving this kind of matrix optimization problems. Numerical experiments also show that the proximal alternating direction method with the relaxed proximal parameters is convergent and generally has a better performance than the classical proximal alternating direction method.

Public health assessment for US Naval Submarine Base, New London, Groton, New London County, Connecticut, Region 1. CERCLIS No. CTD980906515. Final report

International Nuclear Information System (INIS)

1993-01-01

The New London Submarine Base was divided by the town boundaries of Groton to the south and Ledyard to the north in New London County, Connecticut. In 1983, the Navy identified 16 potential source areas of environmental contamination during their investigations. The submarine base was listed on the US Environmental Protection Agency's National Priorities List in August 1990 because of the potential for on-base groundwater contamination to migrate to off-base residential wells that are close to the New London Submarine Base

Results of radioactivity analysis made in Corsica following the navigation incident of the USS Hartford submarine

International Nuclear Information System (INIS)

2003-11-01

No radiological impact has been revealed in relation with the navigation incident of the Uss Hartford submarine at the north of Sardinia. The analysis have been made by the Institute of radiation protection and nuclear safety (I.R.S.N.).The Uss Hartford submarine had hit the bottom of the sea, on the 25. of october 2003, between the islands of Sardinia at a thirty kilometers distance in the south of Bonifacio. The accident had been declared to the public only on the 12. of November 2003. (N.C.)

H2O Contents of Submarine and Subaerial Silicic Pyroclasts from Oomurodashi Volcano, Northern Izu-Bonin Arc

Science.gov (United States)

McIntosh, I. M.; Tani, K.; Nichols, A. R.

2014-12-01

Oomurodashi volcano is an active shallow submarine silicic volcano in the northern Izu-Bonin Arc, located ~20 km south of the inhabited active volcanic island of Izu-Oshima. Oomurodashi has a large (~20km diameter) flat-topped summit located at 100 - 150 metres below sea level (mbsl), with a small central crater, Oomuro Hole, located at ~200 mbsl. Surveys conducted during cruise NT12-19 of R/V Natsushima in 2012 using the remotely-operated vehicle (ROV) Hyper-Dolphin revealed that Oomuro Hole contains numerous active hydrothermal vents and that the summit of Oomurodashi is covered by extensive fresh rhyolitic lava and pumice clasts with little biogenetic or manganese cover, suggesting recent eruption(s) from Oomuro Hole. Given the shallow depth of the volcano summit, such eruptions are likely to have generated subaerial eruption columns. A ~10ka pumiceous subaerial tephra layer on the neighbouring island of Izu-Oshima has a similar chemical composition to the submarine Oomurodashi rocks collected during the NT12-19 cruise and is thought to have originated from Oomurodashi. Here we present FTIR measurements of the H2O contents of rhyolitic pumice from both the submarine deposits sampled during ROV dives and the subaerial tephra deposit on Izu-Oshima, in order to assess magma degassing and eruption processes occurring during shallow submarine eruptions.

Automated trajectory planning for multiple-flyby interplanetary missions

Science.gov (United States)

Englander, Jacob

Many space mission planning problems may be formulated as hybrid optimal control problems (HOCP), i.e. problems that include both real-valued variables and categorical variables. In interplanetary trajectory design problems the categorical variables will typically specify the sequence of planets at which to perform flybys, and the real-valued variables will represent the launch date, ight times between planets, magnitudes and directions of thrust, flyby altitudes, etc. The contribution of this work is a framework for the autonomous optimization of multiple-flyby interplanetary trajectories. The trajectory design problem is converted into a HOCP with two nested loops: an "outer-loop" that finds the sequence of flybys and an "inner-loop" that optimizes the trajectory for each candidate yby sequence. The problem of choosing a sequence of flybys is posed as an integer programming problem and solved using a genetic algorithm (GA). This is an especially difficult problem to solve because GAs normally operate on a fixed-length set of decision variables. Since in interplanetary trajectory design the number of flyby maneuvers is not known a priori, it was necessary to devise a method of parameterizing the problem such that the GA can evolve a variable-length sequence of flybys. A novel "null gene" transcription was developed to meet this need. Then, for each candidate sequence of flybys, a trajectory must be found that visits each of the flyby targets and arrives at the final destination while optimizing some cost metric, such as minimizing ▵v or maximizing the final mass of the spacecraft. Three different classes of trajectory are described in this work, each of which requireda different physical model and optimization method. The choice of a trajectory model and optimization method is especially challenging because of the nature of the hybrid optimal control problem. Because the trajectory optimization problem is generated in real time by the outer-loop, the inner

Modeling ecosystem processes with variable freshwater inflow to the Caloosahatchee River Estuary, southwest Florida. II. Nutrient loading, submarine light, and seagrasses

Science.gov (United States)

Buzzelli, Christopher; Doering, Peter; Wan, Yongshan; Sun, Detong

2014-12-01

Short- and long-term changes in estuarine biogeochemical and biological attributes are consequences of variations in both the magnitude and composition of freshwater inputs. A common conceptualization of estuaries depicts nutrient loading from coastal watersheds as the stressor that promotes algal biomass, decreases submarine light penetration, and degrades seagrass habitats. Freshwater inflow depresses salinity while simultaneously introducing colored dissolved organic matter (color or CDOM) which greatly reduces estuarine light penetration. This is especially true for sub-tropical estuaries. This study applied a model of the Caloosahatchee River Estuary (CRE) in southwest Florida to explore the relationships between freshwater inflow, nutrient loading, submarine light, and seagrass survival. In two independent model series, the loading of dissolved inorganic nitrogen and phosphorus (DIN and DIP) was reduced by 10%, 20%, 30%, and 50% relative to the base model case from 2002 to 2009 (2922 days). While external nutrient loads were reduced by lowering inflow (Q0) in the first series (Q0 series), reductions were accomplished by decreasing the incoming concentrations of DIN and DIP in the second series (NP Series). The model also was used to explore the partitioning of submarine light extinction due to chlorophyll a, CDOM, and turbidity. Results suggested that attempting to control nutrient loading by decreasing freshwater inflow could have minor effects on water column concentrations but greatly influence submarine light and seagrass biomass. This is because of the relative importance of Q0 to salinity and submarine light. In general, light penetration and seagrass biomass decreased with increased inflow and CDOM. Increased chlorophyll a did account for more submarine light extinction in the lower estuary. The model output was used to help identify desirable levels of inflow, nutrient loading, water quality, salinity, and submarine light for seagrass in the lower CRE

The near boiling reactor: design of a small nuclear reactor for extending the operational envelope of the Victoria Class Submarine

International Nuclear Information System (INIS)

Cole, C.; Bonin, H.

2005-01-01

A small, inherently safe nuclear reactor that will provide enough power to maintain the hotel load of the Victoria Class Submarine and extend her operational envelope, has been conceptually designed. The final reactor concept, named the Near Boiling (NB) Reactor, employs TRISO fuel particles in Zirconium cladded fuel rods. The reactor is light water moderated and cooled. The core life is specifically designed to coincide with the refit cycle of the Victoria Class Submarine. The reactor employs a simple and reliable control and shut down system that requires little intervention on the part of the submarine's crew. Also, a kinetic model is developed that demonstrates the inherent safety features of the reactor during several accident scenarios. (author)

The near boiling reactor: design of a small nuclear reactor for extending the operational envelope of the Victoria Class Submarine

Energy Technology Data Exchange (ETDEWEB)

Cole, C.; Bonin, H. [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada)]. E-mail: chris.cole@rmc.ca; bonin-h@rmc.ca

2005-07-01

A small, inherently safe nuclear reactor that will provide enough power to maintain the hotel load of the Victoria Class Submarine and extend her operational envelope, has been conceptually designed. The final reactor concept, named the Near Boiling (NB) Reactor, employs TRISO fuel particles in Zirconium cladded fuel rods. The reactor is light water moderated and cooled. The core life is specifically designed to coincide with the refit cycle of the Victoria Class Submarine. The reactor employs a simple and reliable control and shut down system that requires little intervention on the part of the submarine's crew. Also, a kinetic model is developed that demonstrates the inherent safety features of the reactor during several accident scenarios. (author)

Effects of problem-based learning vs. traditional lecture on Korean nursing students' critical thinking, problem-solving, and self-directed learning.

Science.gov (United States)

Choi, Eunyoung; Lindquist, Ruth; Song, Yeoungsuk

2014-01-01

Problem-based learning (PBL) is a method widely used in nursing education to develop students' critical thinking skills to solve practice problems independently. Although PBL has been used in nursing education in Korea for nearly a decade, few studies have examined its effects on Korean nursing students' learning outcomes, and few Korean studies have examined relationships among these outcomes. The objectives of this study are to examine outcome abilities including critical thinking, problem-solving, and self-directed learning of nursing students receiving PBL vs. traditional lecture, and to examine correlations among these outcome abilities. A quasi-experimental non-equivalent group pretest-posttest design was used. First-year nursing students (N=90) were recruited from two different junior colleges in two cities (GY and GJ) in South Korea. In two selected educational programs, one used traditional lecture methods, while the other used PBL methods. Standardized self-administered questionnaires of critical thinking, problem-solving, and self-directed learning abilities were administered before and at 16weeks (after instruction). Learning outcomes were significantly positively correlated, however outcomes were not statistically different between groups. Students in the PBL group improved across all abilities measured, while student scores in the traditional lecture group decreased in problem-solving and self-directed learning. Critical thinking was positively associated with problem-solving and self-directed learning (r=.71, and r=.50, respectively, plearning (r=.75, pLearning outcomes of PBL were not significantly different from traditional lecture in this small underpowered study, despite positive trends. Larger studies are recommended to study effects of PBL on critical student abilities. Copyright © 2013 Elsevier Ltd. All rights reserved.

Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

Directory of Open Access Journals (Sweden)

Xuezhong Yu

2017-01-01

Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub

Wicked problems in space technology development at NASA

Science.gov (United States)

Balint, Tibor S.; Stevens, John

2016-01-01

Technological innovation is key to enable future space exploration missions at NASA. Technology development, however, is not only driven by performance and resource considerations, but also by a broad range of directly or loosely interconnected factors. These include, among others, strategy, policy and politics at various levels, tactics and programmatics, interactions between stakeholders, resource requirements, performance goals from component to system level, mission infusion targets, portfolio execution and tracking, and technology push or mission pull. Furthermore, at NASA, these influences occur on varying timescales and at diverse geographic locations. Such a complex and interconnected system could impede space technology innovation in this examined segment of the government environment. Hence, understanding the process through NASA's Planning, Programming, Budget and Execution cycle could benefit strategic thinking, planning and execution. Insights could be gained through suitable models, for example assessing the key drivers against the framework of Wicked Problems. This paper discusses NASA specific space technology innovation and innovation barriers in the government environment through the characteristics of Wicked Problems; that is, they do not have right or wrong solutions, only improved outcomes that can be reached through authoritative, competitive, or collaborative means. We will also augment the Wicked Problems model to account for the temporally and spatially coupled, and cyclical nature of this NASA specific case, and propose how appropriate models could improve understanding of the key influencing factors. In turn, such understanding may subsequently lead to reducing innovation barriers, and stimulating technology innovation at NASA. Furthermore, our approach can be adopted for other government-directed environments to gain insights into their structures, hierarchies, operational flow, and interconnections to facilitate circular dialogs towards

Navigation and history of science: autopsy to submarine Kursk. Survival previsions were not sufficient

Directory of Open Access Journals (Sweden)

Ignacio Jáuregui-Lobera

2018-01-01

Full Text Available On August 12, 2000, Saturday, a Russian submarine of the Oscar II class, the K-141 Kursk, sank in the Barents Sea, while sailing as part of the "Summer-X Exercise" manoeuvres. The Kursk was a giant double-hulled submarine, with nine sealed compartments, considered impossible to be sunk. During the manoeuvres, at 08:51 local time, the Kursk requested permission to prepare a torpedo and it received the response "Dobro" (good in English. At 11:29:34 (07:29:50 UTC the Norwegian seismic monitoring network (NORSAR registered an earthquake of intensity 1.5 on the Richter scale at northeast of Murmansk, approximately 250 Km from Norway, and 80 Km from the Kola Peninsula. At 11:31:48, two minutes and fourteen seconds later, a second movement, 4.2 on the Richter scale and 250 times longer than the first, was recorded by different seismographs, even being detected in Alaska. It was equivalent to an explosion of 2-3 Tm of TNT. After a great confusion and propaganda, there was no choice other than to accept the facts: the Kursk had suffered two explosions, had sunk and the whole crew had perished. But what happened in that submarine? It seems clear that survival previsions were not sufficient.

A direct sampling method to an inverse medium scattering problem

KAUST Repository

Ito, Kazufumi; Jin, Bangti; Zou, Jun

2012-01-01

In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when

The Economics of NASA Mission Cost Reserves

Science.gov (United States)

Whitley, Sally; Shinn, Stephen

2012-01-01

Increases in NASA mission costs are well-noted but not well-understood, and there is little evidence that they are decreasing in frequency or amount over time. The need to control spending has led to analysis of the causes and magnitude of historical mission overruns, and many program control efforts are being implemented to attempt to prevent or mitigate the problem (NPR 7120). However, cost overruns have not abated, and while some direct causes of increased spending may be obvious (requirements creep, launch delays, directed changes, etc.), the underlying impetus to spend past the original budget may be more subtle. Gaining better insight into the causes of cost overruns will help NASA and its contracting organizations to avoid .them. This paper hypothesizes that one cause of NASA mission cost overruns is that the availability of reserves gives project team members an incentive to make decisions and behave in ways that increase costs. We theorize that the presence of reserves is a contributing factor to cost overruns because it causes organizations to use their funds less efficiently or to control spending less effectively. We draw a comparison to the insurance industry concept of moral hazard, the phenomenon that the presence of insurance causes insureds to have more frequent and higher insurance losses, and we attempt to apply actuarial techniques to quantifY the increase in the expected cost of a mission due to the availability of reserves. We create a theoretical model of reserve spending motivation by defining a variable ReserveSpending as a function of total reserves. This function has a positive slope; for every dollar of reserves available, there is a positive probability of spending it. Finally, the function should be concave down; the probability of spending each incremental dollar of reserves decreases progressively. We test the model against available NASA CADRe data by examining missions with reserve dollars initially available and testing whether

Submarine groundwater discharge within a landslide scar at the French Mediterranean coast

NARCIS (Netherlands)

Oehler, Till; Mogollón, José M.; Moosdorf, Nils; Winkler, Andreas; Kopf, Achim; Pichler, Thomas

2017-01-01

Submarine groundwater discharge (SGD), the flow of fresh and saline groundwater from the seabed into the coastal ocean, has been intensively investigated in the recent years. This research has usually been restricted to shallow water and intertidal areas, whereas knowledge about groundwater seepage

Development of an Indexing Media Filtration System for Long Duration Space Missions

Science.gov (United States)

Agui, Juan H.; Vijayakumar, R.

2013-01-01

The effective maintenance of air quality aboard spacecraft cabins will be vital to future human exploration missions. A key component will be the air cleaning filtration system which will need to remove a broad size range of particles derived from multiple biological and material sources. In addition, during surface missions any extraterrestrial planetary dust, including dust generated by near-by ISRU equipment, which is tracked into the habitat will also need to be managed by the filtration system inside the pressurized habitat compartments. An indexing media filter system is being developed to meet the demand for long-duration missions that will result in dramatic increases in filter service life and loading capacity, and will require minimal crew involvement. The filtration system consists of three stages: an inertial impactor stage, an indexing media stage, and a high-efficiency filter stage, packaged in a stacked modular cartridge configuration. Each stage will target a specific range of particle sizes that optimize the filtration and regeneration performance of the system. An 1/8th scale and full-scale prototype of the filter system have been fabricated and have been tested in the laboratory and reduced gravity environments that simulate conditions on spacecrafts, landers and habitats. Results from recent laboratory and reduce-gravity flight tests data will be presented. The features of the new filter system may also benefit other closed systems, such as submarines, and remote location terrestrial installations where servicing and replacement of filter units is not practical.

Gravitational, erosional and depositional processes on volcanic ocean islands: Insights from the submarine morphology of Madeira Archipelago

Science.gov (United States)

Quartau, Rui; Ramalho, Ricardo S.; Madeira, José; Santos, Rúben; Rodrigues, Aurora; Roque, Cristina; Carrara, Gabriela; Brum da Silveira, António

2018-01-01

The submarine flanks of volcanic ocean islands are shaped by a variety of physical processes. Whilst volcanic constructional processes are relatively well understood, the gravitational, erosional and depositional processes that lead to the establishment of large submarine tributary systems are still poorly comprehended. Until recently, few studies have offered a comprehensive source-to-sink approach, linking subaerial morphology with near-shore shelf, slope and far-field abyssal features. In particular, few studies have addressed how different aspects of the subaerial part of the system (island height, climate, volcanic activity, wave regime, etc.) may influence submarine flank morphologies. We use multibeam bathymetric and backscatter mosaics of an entire archipelago - Madeira - to investigate the development of their submarine flanks. Crucially, this dataset extends from the nearshore to the deep sea, allowing a solid correlation between submarine morphologies with the physical and geological setting of the islands. In this study we also established a comparison with other island settings, which allowed us to further explore the wider implications of the observations. The submarine flanks of the Madeira Archipelago are deeply dissected by large landslides, most of which also affected the subaerial edifices. Below the shelf break, landslide chutes extend downslope forming poorly defined depositional lobes. Around the islands, a large tributary system composed of gullies and channels has formed where no significant rocky/ridge outcrops are present. In Madeira Island these were likely generated by turbidity currents that originated as hyperpycnal flows, whilst on Porto Santo and Desertas their origin is attributed to storm-induced offshore sediment transport. At the lower part of the flanks (-3000 to -4300 m), where seafloor gradients decrease to 0.5°-3°, several scour and sediment wave fields are present, with the former normally occurring upslope of the latter

Shelf erosion and submarine river canyons: implications for deep-sea oxygenation and ocean productivity during glaciation

Directory of Open Access Journals (Sweden)

I. Tsandev

2010-06-01

Full Text Available The areal exposure of continental shelves during glacial sea level lowering enhanced the transfer of erodible reactive organic matter to the open ocean. Sea level fall also activated submarine canyons thereby allowing large rivers to deposit their particulate load, via gravity flows, directly in the deep-sea. Here, we analyze the effects of shelf erosion and particulate matter re-routing to the open ocean during interglacial to glacial transitions, using a coupled model of the marine phosphorus, organic carbon and oxygen cycles. The results indicate that shelf erosion and submarine canyon formation may significantly lower deep-sea oxygen levels, by up to 25%, during sea level low stands, mainly due to the supply of new material from the shelves, and to a lesser extent due to particulate organic matter bypassing the coastal zone. Our simulations imply that deep-sea oxygen levels can drop significantly if eroded shelf material is deposited to the seafloor. Thus the glacial ocean's oxygen content could have been significantly lower than during interglacial stages. Primary production, organic carbon burial and dissolved phosphorus inventories are all affected by the erosion and rerouting mechanisms. However, re-routing of the continental and eroded shelf material to the deep-sea has the effect of decoupling deep-sea oxygen demand from primary productivity in the open ocean. P burial is also not affected showing a disconnection between the biogeochemical cycles in the water column and the P burial record.

Frontally confined versus frontally emergent submarine landslides: A 3D seismic characterisation

Energy Technology Data Exchange (ETDEWEB)

Frey-Martinez, Jose; Cartwright, Joe; James, David [3DLab. School of Earth, Ocean and Planetary Sciences, Cardiff University, P.O. Box 914, Cardiff CF10 3YE (United Kingdom)

2006-06-15

Three-dimensional (3D) seismic data from the continental margin offshore Israel (Eastern Mediterranean) have been used to analyse the compressional structures within the toe regions of two major buried submarine landslides: the ISC and the T20. Both landslides are developed within a Plio-Pleistocene slope succession composed predominately of claystones, limestones and siltstones. The high spatial resolution provided by the seismic data has allowed a detailed analysis of the geometries and deformational structures within the toe regions of the two landslides, and this has been used to develop a mechanical model for their development. Importantly, it has been recognised that submarine landslides may be divided into two main types according to their form of frontal emplacement: frontally confined and frontally emergent. In the former, the landslide undergoes a restricted downslope translation and does not overrun the undeformed downslope strata. In the latter, much larger downslope translation occurs because the landslide is able to ramp up from its original basal shear surface and translate in an unconfined manner over the seafloor. We propose that these two types of submarine landslides are end members of a continuum of gravity-driven slope failure processes, which extends from landslides where the headscarp is completely evacuated, to landslides where the material remains entirely within the headscarp. The differentiation of these two end members is of critical importance as their respective mechanisms of formation, downslope propagation and emplacement are significantly different, and hence need to be taken into consideration when analysing their respective kinematics. (author)

Environmental monitoring of El Hierro Island submarine volcano, by combining low and high resolution satellite imagery

Science.gov (United States)

Eugenio, F.; Martin, J.; Marcello, J.; Fraile-Nuez, E.

2014-06-01

El Hierro Island, located at the Canary Islands Archipelago in the Atlantic coast of North Africa, has been rocked by thousands of tremors and earthquakes since July 2011. Finally, an underwater volcanic eruption started 300 m below sea level on October 10, 2011. Since then, regular multidisciplinary monitoring has been carried out in order to quantify the environmental impacts caused by the submarine eruption. Thanks to this natural tracer release, multisensorial satellite imagery obtained from MODIS and MERIS sensors have been processed to monitor the volcano activity and to provide information on the concentration of biological, chemical and physical marine parameters. Specifically, low resolution satellite estimations of optimal diffuse attenuation coefficient (Kd) and chlorophyll-a (Chl-a) concentration under these abnormal conditions have been assessed. These remote sensing data have played a fundamental role during field campaigns guiding the oceanographic vessel to the appropriate sampling areas. In addition, to analyze El Hierro submarine volcano area, WorldView-2 high resolution satellite spectral bands were atmospherically and deglinted processed prior to obtain a high-resolution optimal diffuse attenuation coefficient model. This novel algorithm was developed using a matchup data set with MERIS and MODIS data, in situ transmittances measurements and a seawater radiative transfer model. Multisensor and multitemporal imagery processed from satellite remote sensing sensors have demonstrated to be a powerful tool for monitoring the submarine volcanic activities, such as discolored seawater, floating material and volcanic plume, having shown the capabilities to improve the understanding of submarine volcanic processes.

Evaluation and comparison of electric propulsion motors for submarines

OpenAIRE

Harbour, Joel P.

2001-01-01

CIVINS (Civilian Institutions) Thesis document The Navy has announced its conviction to make its warships run on electric power through the decision to make its newest line of destroyers propelled with an electric propulsion system. Several ship construction firms and electric motor manufacturers are thus striving to develop enabling technology, including high power density motors. The purpose of this thesis is to evaluate some of the proposed motor designs for use in a submarine. Permanen...

Direct methods of solution for problems in mechanics from invariance principles

International Nuclear Information System (INIS)

Rajan, M.

1986-01-01

Direct solutions to problems in mechanics are developed from variational statements derived from the principle of invariance of the action integral under a one-parameter family of infinitesimal transformations. Exact, direct solution procedures for linear systems are developed by a careful choice of the arbitrary functions used to generate the infinitesimal transformations. It is demonstrated that the well-known methods for the solution of differential equations can be directly adapted to the required variational statements. Examples in particle and continuum mechanics are presented

CLAM - CoLlAborative eMbedded networks for submarine surveillance: An overview

NARCIS (Netherlands)

Meratnia, Nirvana; Havinga, Paul J.M.; Casari, Paolo; Petrioli, Chiara; Grythe, Knut; Husoy, Thor; Zorzi, Michele

2011-01-01

This paper provides an overview of the CLAM project, which aims at developing a collaborative embedded monitoring and control platform for submarine surveillance by combining cutting edge acoustic vector sensor technology and 1D, 2D, 3D sensor arrays, underwater wireless sensor networks protocol

The Military Inventory Routing Problem with Direct Delivery

Science.gov (United States)

2014-03-27

helicopters led to the use of “ Jingle Air”, a group of contractors that operate helicopters in support of resupply missions. During a deployment to...PMCS) between routes. This also roughly matches the average flight hours associated with a “ Jingle Air” mission of 6.4 hours [12]. In order to...an even multiple of the standard pallet weights used by the Army. Furthermore, the average load of a “ Jingle Air” helicopter is 4,000 lbs. [12

Constraining the sedimentology and stratigraphy of submarine intraslope lobe deposits using exhumed examples from the Karoo Basin, South Africa

OpenAIRE

Flint, Stephen; Hodgson, David; Spychala, Yvonne; Mountney, Nigel

2017-01-01

Intraslope lobe deposits provide a process record of the infill of accommodation on submarine slopes and their recognition enables the accurate reconstruction of the stratigraphic evolution of submarine slope systems. Extensive exposures of discrete sand-prone packages in Units D/E and E, Fort Brown Formation, Karoo Basin, South Africa, permit analysis of the sedimentology and stacking patterns of three intraslope lobe complexes and their palaeogeographic reconstruction via bed-scale analysis...

Research on Life Science and Life Support Engineering Problems of Manned Deep Space Exploration Mission

Science.gov (United States)

Qi, Bin; Guo, Linli; Zhang, Zhixian

2016-07-01

Space life science and life support engineering are prominent problems in manned deep space exploration mission. Some typical problems are discussed in this paper, including long-term life support problem, physiological effect and defense of varying extraterrestrial environment. The causes of these problems are developed for these problems. To solve these problems, research on space life science and space medical-engineering should be conducted. In the aspect of space life science, the study of space gravity biology should focus on character of physiological effect in long term zero gravity, co-regulation of physiological systems, impact on stem cells in space, etc. The study of space radiation biology should focus on target effect and non-target effect of radiation, carcinogenicity of radiation, spread of radiation damage in life system, etc. The study of basic biology of space life support system should focus on theoretical basis and simulating mode of constructing the life support system, filtration and combination of species, regulation and optimization method of life support system, etc. In the aspect of space medical-engineering, the study of bio-regenerative life support technology should focus on plants cultivation technology, animal-protein production technology, waste treatment technology, etc. The study of varying gravity defense technology should focus on biological and medical measures to defend varying gravity effect, generation and evaluation of artificial gravity, etc. The study of extraterrestrial environment defense technology should focus on risk evaluation of radiation, monitoring and defending of radiation, compound prevention and removal technology of dust, etc. At last, a case of manned lunar base is analyzed, in which the effective schemes of life support system, defense of varying gravity, defense of extraterrestrial environment are advanced respectively. The points in this paper can be used as references for intensive study on key

Emblem for the third manned Skylab mission - Skylab 4

Science.gov (United States)

1973-01-01

This is the emblem for the third manned Skylab mission. It will be a mission of up to 56 days. The symbols in the patch refer to the three major areas of investigation proposed in the mission. The tree represents man's natural environment and relates directly to the Skylab mission objectives of advancing the study of Earth resources. The hydrogen atom, as the basic building block of the universe, represents man's exploration of the physical world, his application of knowledge, and his development of technology. Since the Sun is composed primarily of hydrogen, it is appropriate that the symbol refers to the solar physics mission objectives. The human silhouette represents mankind and the human capacity to direct technology with a wisdom tempered by regard for his natural environment. It also directly relates to the Skylab medical studies of man himself. The rainbow, adopted from the Biblical story of the flood, symbolizes the promise that is offered man. It embraces man and extends to t

An abstract approach to some spectral problems of direct sum differential operators

Directory of Open Access Journals (Sweden)

Maksim S. Sokolov

2003-07-01

Full Text Available In this paper, we study the common spectral properties of abstract self-adjoint direct sum operators, considered in a direct sum Hilbert space. Applications of such operators arise in the modelling of processes of multi-particle quantum mechanics, quantum field theory and, specifically, in multi-interval boundary problems of differential equations. We show that a direct sum operator does not depend in a straightforward manner on the separate operators involved. That is, on having a set of self-adjoint operators giving a direct sum operator, we show how the spectral representation for this operator depends on the spectral representations for the individual operators (the coordinate operators involved in forming this sum operator. In particular it is shown that this problem is not immediately solved by taking a direct sum of the spectral properties of the coordinate operators. Primarily, these results are to be applied to operators generated by a multi-interval quasi-differential system studied, in the earlier works of Ashurov, Everitt, Gesztezy, Kirsch, Markus and Zettl. The abstract approach in this paper indicates the need for further development of spectral theory for direct sum differential operators.

Experimental Support for Evaluation of the Victoria Class Virtual Submarine (VCVS)

Science.gov (United States)

2012-03-01

comportementales de ce genre . y A P P R O V A L S H E E T Document No. 5283-001 Version 03 Document Name: Experimental Support for Evaluation...encountered that reduced access to HMCS Corner Brook: 11  Cold moves to charge submarine batteries;  Filming events; and,  Slight delays due

Improved recovery from Gulf of Mexico reservoirs. Volume I (of 4): Task 1, conduct research on mud-rich submarine fans. Final report, February 14, 1995--October 13, 1996

Energy Technology Data Exchange (ETDEWEB)

Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.

1997-01-13

The objective for this portion of the research involved conducting field studies and laboratory investigations to develop and refine models for mud-rich submarine fan architectures used by seismic analysis and reservoir engineers. These research aspects have been presented in two papers as follows: (1) Bouma, A.H., {open_quotes}Review of Fine-Grained Submarine Fans and Turbidite Systems{close_quotes}; (2) Kirkova, J.T. and Lorenzo, J.M., {open_quotes}Synthetic Seismic Modeling of Measured Submarine Fans Sections, Case Study of the Tanqua Complex, Karoo, South Africa{close_quotes} The {open_quotes}Review of Fine-Grained Submarine Fans and Turbidite Systems{close_quotes} by Arnold Bouma discusses research targeted toward stimulating an increase in oil and gas recovery by developing new and improved geological understanding. The {open_quotes}Synthetic Seismic Modeling of Measured Submarine Fan Sections, Case Study of the Tanqua Complex, Karoo, South Africa{close_quotes} by J.T. Kirkova and J.M. Lorenso discusses the limitations of verticle resolution and how this affects the interpretation and characterization of submarine fan complexes.

Psychosocial interactions during ISS missions

Science.gov (United States)

Kanas, N. A.; Salnitskiy, V. P.; Ritsher, J. B.; Gushin, V. I.; Weiss, D. S.; Saylor, S. A.; Kozerenko, O. P.; Marmar, C. R.

2007-02-01

Based on anecdotal reports from astronauts and cosmonauts, studies of space analog environments on Earth, and our previous research on the Mir Space Station, a number of psychosocial issues have been identified that can lead to problems during long-duration space expeditions. Several of these issues were studied during a series of missions to the International Space Station. Using a mood and group climate questionnaire that was completed weekly by crewmembers in space and personnel in mission control, we found no evidence to support the presence of predicted decrements in well-being during the second half or in any specific quarter of the missions. The results did support the predicted displacement of negative feelings to outside supervisors among both crew and ground subjects. There were several significant differences in mood and group perceptions between Americans and Russians and between crewmembers and mission control personnel. Crewmembers related cohesion to the support role of their leader, and mission control personnel related cohesion to both the task and support roles of their leader. These findings are discussed with reference to future space missions.

Missions to Venus

Science.gov (United States)

Titov, D. V.; Baines, K. H.; Basilevsky, A. T.; Chassefiere, E.; Chin, G.; Crisp, D.; Esposito, L. W.; Lebreton, J.-P.; Lellouch, E.; Moroz, V. I.; Nagy, A. F.; Owen, T. C.; Oyama, K.-I.; Russell, C. T.; Taylor, F. W.; Young, R. E.

2002-10-01

Venus has always been a fascinating objective for planetary studies. At the beginning of the space era Venus became one of the first targets for spacecraft missions. Our neighbour in the solar system and, in size, the twin sister of Earth, Venus was expected to be very similar to our planet. However, the first phase of Venus spacecraft exploration in 1962-1992 by the family of Soviet Venera and Vega spacecraft and US Mariner, Pioneer Venus, and Magellan missions discovered an entirely different, exotic world hidden behind a curtain of dense clouds. These studies gave us a basic knowledge of the conditions on the planet, but generated many more questions concerning the atmospheric composition, chemistry, structure, dynamics, surface-atmosphere interactions, atmospheric and geological evolution, and the plasma environment. Despite all of this exploration by more than 20 spacecraft, the "morning star" still remains a mysterious world. But for more than a decade Venus has been a "forgotten" planet with no new missions featuring in the plans of the world space agencies. Now we are witnessing the revival of interest in this planet: the Venus Orbiter mission is approved in Japan, Venus Express - a European orbiter mission - has successfully passed the selection procedure in ESA, and several Venus Discovery proposals are knocking at the doors of NASA. The paper presents an exciting story of Venus spacecraft exploration, summarizes open scientific problems, and builds a bridge to the future missions.

Direction and stability of bifurcating solutions for a Signorini problem

Czech Academy of Sciences Publication Activity Database

Eisner, J.; Kučera, Milan; Recke, L.

2015-01-01

Roč. 113, January (2015), s. 357-371 ISSN 0362-546X Institutional support: RVO:67985840 Keywords : Signorini problem * variational inequality * bifurcation direction Subject RIV: BA - General Mathematics Impact factor: 1.125, year: 2015 http://www.sciencedirect.com/science/article/pii/S0362546X14003228

Tsunamis caused by submarine slope failures along western Great Bahama Bank.

Science.gov (United States)

Schnyder, Jara S D; Eberli, Gregor P; Kirby, James T; Shi, Fengyan; Tehranirad, Babak; Mulder, Thierry; Ducassou, Emmanuelle; Hebbeln, Dierk; Wintersteller, Paul

2016-11-04

Submarine slope failures are a likely cause for tsunami generation along the East Coast of the United States. Among potential source areas for such tsunamis are submarine landslides and margin collapses of Bahamian platforms. Numerical models of past events, which have been identified using high-resolution multibeam bathymetric data, reveal possible tsunami impact on Bimini, the Florida Keys, and northern Cuba. Tsunamis caused by slope failures with terminal landslide velocity of 20 ms -1 will either dissipate while traveling through the Straits of Florida, or generate a maximum wave of 1.5 m at the Florida coast. Modeling a worst-case scenario with a calculated terminal landslide velocity generates a wave of 4.5 m height. The modeled margin collapse in southwestern Great Bahama Bank potentially has a high impact on northern Cuba, with wave heights between 3.3 to 9.5 m depending on the collapse velocity. The short distance and travel time from the source areas to densely populated coastal areas would make the Florida Keys and Miami vulnerable to such low-probability but high-impact events.

ENIQ-qualified visual examinations by means of a remote controlled submarine

Energy Technology Data Exchange (ETDEWEB)

Tsvetkov, Elenko; Heinsius, Jan [AREVA GmbH, Erlangen (Germany)

2015-07-15

Remote visual examination is one of the most important methods for non- destructive in-service inspections of primary components in nuclear power plants. It features two main advantages: the short examination duration and the fast interpretation of results. AREVA offers operators of nuclear power plants the ''SUSI 420 HD'' SUbmarine System for Inspections to perform ENIQ-qualified visual examinations during outages without working on the critical path and causing any delay in the time schedule. The system is a remotely operated manipulator equipped with a high definition camera. With a weight of only 25 kg, there is no need for a crane to put the submarine into water. More-over, nor the use of the refueling machine neither the auxiliary bridge is required. In this way the visual examination can be performed in parallel to other activities which are on the critical path. The article takes a closer look at the essential parameters: illumination, examination distance, viewing angle, scanning speed, positioning accuracy and sizing of indications. It describes how the system can fulfill these parameters through some adaptations.

Logistics of nuclear fuel production for nuclear submarines

International Nuclear Information System (INIS)

Guimaraes, Leonam dos Santos

2000-01-01

The future acquisition of nuclear attack submarines by Brazilian Navy along next century will imply new requirements on Naval Logistic Support System. These needs will impact all the six logistic functions. Among them, fuel supply could be considered as the one which requires the most important capacitating effort, including not only technological development of processes but also the development of a national industrial basis for effective production of nuclear fuel. This paper presents the technical aspects of the processes involved and an annual production dimensioning for an squadron composed by four units. (author)

An Analysis of the Effectiveness of a New Watchstanding Schedule for U.S. Submariners

National Research Council Canada - National Science Library

Osborn, Christopher

2004-01-01

A need exists within the U.S. submarine force to employ an operational schedule that provides more sleep and that is in better alignment with human circadian rhythms, thus improving cognitive effectiveness...

Future directions in 980-nm pump lasers: submarine deployment to low-cost watt-class terrestrial pumps

Science.gov (United States)

Gulgazov, Vadim N.; Jackson, Gordon S.; Lascola, Kevin M.; Major, Jo S.; Parke, Ross; Richard, Tim; Rossin, Victor V.; Zhang, Kai

1999-09-01

. Since the failure rate allowable for an amplifier is not a function of the number of pumps employed in the amplifier, the allowable failure rate of an individual pump laser is decreasing for next-generation amplifiers. This will lead to specifications for terrestrial pumps well below 1000 FIT, and may lead to the case where high power amplifiers need laser pump reliability to approach 100 FIT. In addition, 980 nm laser diodes are now being deployed in submarine systems where failure rates lower than 100 FIT are commonly specified. It is obvious that both terrestrial and submarine markets are pushing allowable failure rates for pumps for optical amplifiers to continually decrease. A second push for improvement is in the output power of 980 nm pump modules. There exist a number of motivations for increasing the output power of pump lasers. First, each additional channel in a DWDM system requires additional power. To first order, a doubling in channel count implies a doubling in pump power. Second, larger amplifiers require multiple pumps. Higher output power from pump modules allows for fewer pumps, less complicated control systems and smaller size amplifiers. The discussion of this paper will focus on how current development progress of 980 nm laser diodes addresses these issues: better reliability and higher output powers.

Software Architecture for Anti-Submarine Warfare Unmanned Surface Vehicles

Science.gov (United States)

2016-09-01

would ordinarily require the placement of more sonobuoys in the predicted path of the submarine, but if the USVs could sprint ahead just a few hundred...few yards/ meters . Once an agent has accurately resolved their current position on the globe, and identified obstacles to avoid, the task of navigation...Software Engineering with Abstractions. Reading, MA: Addison-Wesley, 1991. [7] B. Harris, “Hitler’s Lost Sub: 400 Years of Subs (1580-1861),” PBS, 2016

Model of a Nuclear Security Naval Agency for radiation control of the Industrial Complex of of Submarine Construction and Maintenance Ship with Nuclear Propulsion

International Nuclear Information System (INIS)

Lins Junior, Amilton de Sousa

2017-01-01

Due to the construction, by Brazilian Navy, of a Submarine Construction and Maintenance Ship with Nuclear Propulsion, where, among other activities, the commissioning and exchange of the fuel elements of the reactor in the future Nuclear Submarine, and of a Naval Base where the Nuclear Submarine and the Conventional Submarines, it is necessary the establishment of a Nuclear Security Naval Agency to monitor activities involving ionizing radiation sources and nuclear materials aimed at the radiological protection of exposed occupationally individuals (IOE), the general public and the environment. It should be noted that nuclear and radioactive material will be present only in a part of the yard called Radiological Complex. Therefore, the development of a structure for the control of the Radiological Complex is fundamental, considering that the future licensing process will be unprecedented in Brazil and will face several difficulties. This work presents a model of a structure for the radiological control of the industrial complex for the construction and maintenance of the submarine with nuclear propulsion, as well as the fundamental concepts of the activities, such as inspection, regulations and authorizations, to be carried out by the various component sectors of the Nuclear Security Naval Agency. (author)

Coastal submarine hydrothermal activity off northern Baja California: 2. Evolutionary history and isotope geochemistry

Science.gov (United States)

Vidal, Victor M. V.; Vidal, Francisco V.; Isaacs, John D.

1981-10-01

A geochemical model of the Punta Banda submarine hydrothermal system (PBSHS) and Ensenada quadrangle subaerial hot springs is developed using 18O/16O, D/H, 34S/32S, 3H, water and gas chemistry. The PBSHS water is a primary high temperature, acid, reducing fluid of old seawater origin which has been titrated by cold, alkaline groundwater of meteoric origin. The final exiting solutions represent a 1 : 1 mixture of the two primary mixing components. In contrast, the subaerial hot spring waters are of unmixed meteoric origin. The subaerial hot spring gas is predominantly atmospheric N2, while the PBSHS contains large amounts of CH4 and N2 derived from trapped marine sediments of Cretaceous age; δS34 values of sampled hydrothermal waters are similar to Cretaceous marine sulfate values and suggest that the waters contacted Cretaceous marine sedimentary strata. The presence of the Alisitos and Rosario marine sedimentary formations of Cretaceous age within the Ensenada-Punta Banda quadrangle renders support to the above hypothesis. The data also demonstrate that pyrite mineralization and deposition in submarine hydrothermal environments result from the complexing of ferrous iron with elemental sulfur and sulfide and that submarine hydrothermal activity acts as a major source of silica, Ca2+, and trace metals and as a major sink for seawater Mg2+ and SO42-.

Man-machine interface in a submarine command and weapon control system: features and design experience

Directory of Open Access Journals (Sweden)

Johan H. Aas

1989-01-01

Full Text Available Important man-machine interface (MMI issues concerning a submarine command and weapon control system (CWCS such as crew organization, automation level and decision support are discussed in this paper. Generic submarine CWCS functions and operating conditions are outlined. Detailed, dynamic and real-time prototypes were used to support the MMI design. The prototypes are described and experience with detailed prototyping is discussed. Some of the main interaction principles are summarized and a restricted example of the resulting design is given. Our design experience and current work have been used to outline future perspectives of MMI design in naval CWCSs. The need for both formal and experimental approaches is emphasized.

(abstract) Telecommunications for Mars Rovers and Robotic Missions

Science.gov (United States)

Cesarone, Robert J.; Hastrup, Rolf C.; Horne, William; McOmber, Robert

1997-01-01

Telecommunications plays a key role in all rover and robotic missions to Mars both as a conduit for command information to the mission and for scientific data from the mission. Telecommunications to the Earth may be accomplished using direct-to-Earth links via the Deep Space Network (DSN) or by relay links supported by other missions at Mars. This paper reviews current plans for missions to Mars through the 2005 launch opportunity and their capabilities in support of rover and robotic telecommunications.

Consensus problem in directed networks of multi-agents via nonlinear protocols

International Nuclear Information System (INIS)

Liu Xiwei; Chen Tianping; Lu Wenlian

2009-01-01

In this Letter, the consensus problem via distributed nonlinear protocols for directed networks is investigated. Its dynamical behaviors are described by ordinary differential equations (ODEs). Based on graph theory, matrix theory and the Lyapunov direct method, some sufficient conditions of nonlinear protocols guaranteeing asymptotical or exponential consensus are presented and rigorously proved. The main contribution of this work is that for nonlinearly coupled networks, we generalize the results for undirected networks to directed networks. Consensus under pinning control technique is also developed here. Simulations are also given to show the validity of the theories.

Flight mission control for multiple spacecraft

Science.gov (United States)

Ryan, Robert E.

1990-10-01

A plan developed by the Jet Propulsion Laboratory for mission control of unmanned spacecraft is outlined. A technical matrix organization from which, in the past, project teams were formed to uniquely support a mission is replaced in this new plan. A cost effective approach was needed to make best use of limited resources. Mission control is a focal point operations and a good place to start a multimission concept. Co-location and sharing common functions are the keys to obtaining efficiencies at minimum additional risk. For the projects, the major changes are sharing a common operations area and having indirect control of personnel. The plan identifies the still direct link for the mission control functions. Training is a major element in this plan. Personnel are qualified for a position and certified for a mission. This concept is more easily accepted by new missions than the ongoing missions.

Assessment of Submarine Slope Stability on the Continental Margin off SW Taiwan

Science.gov (United States)

Hsu, Huai-Houh; Dong, Jia-Jyun; Cheng, Win-Bin; Su, Chih-Chieh

2017-04-01

The abundant gas hydrate reservoirs are distributed in the southwest (SW) off Taiwan. To explore this new energy, geological methods were systematically used and mainly emphasized on the storage potential evaluation. On the other hand, the correlation between gas hydrate dissociation and submarine slope stability is also an important issue. In this study, three submarine profiles on the active and passive continental margin were selected and assessed their slope stabilities by considering two influence factors (seismic forces and number of sedimentary layers). The gravity corers obtained from these three sites (Xiaoliuqiu, Yuan-An Ridge, and Pointer Ridge) to conduct soil laboratory tests. The physical property tests and isotropically consolidated undrained (CIU) triaxial tests were carried out to establish reference properties and shear strength parameters. Before the stability analysis is performed, it is also necessary to construct the seabed profile. For each submarine profile, data from P-waves and from S-waves generated by P-S conversion on reflection from airgun shots recorded along one line of ocean bottom seismometers were used to construct 2-D velocity sections. The seabed strata could be simplified to be only one sedimentary layer or to be multilayer in accordance with the velocity structure profile. Results show the safety factors (FS) of stability analysis are obviously different in considering the number of sedimentary layers, especially for a very thin layer of sediments on a steep slope. The simplified strata condition which treated all seabed strata as only one sedimentary layer might result in the FS lower than 1 and the slope was in an unstable state. On the contrary, the FS could be higher than 10 in a multilayer condition.

Localizing Submarine Earthquakes by Listening to the Water Reverberations

Science.gov (United States)

Castillo, J.; Zhan, Z.; Wu, W.

2017-12-01

Mid-Ocean Ridge (MOR) earthquakes generally occur far from any land based station and are of moderate magnitude, making it complicated to detect and in most cases, locate accurately. This limits our understanding of how MOR normal and transform faults move and the manner in which they slip. Different from continental events, seismic records from earthquakes occurring beneath the ocean floor show complex reverberations caused by P-wave energy trapped in the water column that are highly dependent of the source location and the efficiency to which energy propagated to the near-source surface. These later arrivals are commonly considered to be only a nuisance as they might sometimes interfere with the primary arrivals. However, in this study, we take advantage of the wavefield's high sensitivity to small changes in the seafloor topography and the present-day availability of worldwide multi-beam bathymetry to relocate submarine earthquakes by modeling these water column reverberations in teleseismic signals. Using a three-dimensional hybrid method for modeling body wave arrivals, we demonstrate that an accurate hypocentral location of a submarine earthquake (<5 km) can be achieved if the structural complexities near the source region are appropriately accounted for. This presents a novel way of studying earthquake source properties and will serve as a means to explore the influence of physical fault structure on the seismic behavior of transform faults.

Submarine Landslides and Mass-Transport Deposition in the Nankai fore-arc

Science.gov (United States)

Strasser, M.; Henry, P.; Kanamatsu, T.; Moe, K.; Moore, G. F.; IODP Expedition 333 Scientists

2011-12-01

Multiple lines of evidence exist for a range of sediment mass movement processes within the shallow megasplay fault zone (MSFZ) area and the adjacent slope basin in the outer fore-arc of the Nankai subduction zone, Japan. Diagnostic features observed in 3-D reflection seismic data and in cores from Integrated Ocean Drilling Program (IODP) Expedition 316 document a complex mass movement history spanning at least ˜2.87 million years. Various modes and scales of sediment remobilization can be related to the different morphotectonic settings in which they occurred and allow integration of knowledge on the spatial and temporal distribution of submarine landslides into a holistic reconstruction of the tectonostratigraphic evolution. New data from the most-recent Nankai IODP Expedition 333, which drilled and cored a Pleistocene-to-Holocene succession of the slope-basin seaward of the MSFZ, provides unprecedented details on submarine landslide processes occurring over the last Million year. The slope-basin represents the depocentre for downslope sediment transport and is characterized in 3-D reflection seismic data by several mass-transport deposits (MTDs), including an up to 180 m thick MTD. Here we present D/V Chikyu shipboard results and first post cruise results from Site C0018, including litho- bio- magneto- tephra- and stable isotope-stratigraphy, X-ray computed tomography analysis and physical properties data. Six MTDs were identified from visual core description and X-ray CT-scans. The thickest MTD is also the oldest (emplaced between 0.85 and 1.05 Ma) and it coincides with a lithological transition between a sandy turbidite sequence below, and ash-bearing hemipelagites comprising several MTDs above. Deformation styles within the MTD are heterogeneous: intervals of disturbed sediments are interbedded within intervals inferred to retain original, coherent bedding. In three occurrences the base of the MTD is defined by a shear zone within fine-grained sediments

The landslide problem

Directory of Open Access Journals (Sweden)

G. Shanmugam

2015-04-01

years (e.g., sea-level lowstands. (6 The comparison of H/L (fall height/runout distance ratios of MTD in subaerial environments with H/L ratios of MTD in submarine and extraterrestrial environments is incongruous because of differences in data sources (e.g., outcrop vs. seismic or radar images. (7 Slides represent the pre-transport disposition of strata and their reservoir quality (i.e., porosity and permeability of the provenance region, whereas debrites reflect post-transport depositional texture and reservoir quality. However, both sandy slides and sandy debrites could generate blocky wireline (gamma-ray log motifs. Therefore, reservoir characterization of deep-water strata must be based on direct examination of the rocks and related process-specific facies interpretations, not on wireline logs or on seismic profiles and related process-vague facies interpretations. A solution to these problems is to apply the term “landslide” solely to cases in which a sliding motion can be empirically determined. Otherwise, a general term MTD is appropriate. This decree is not just a quibble over semantics; it is a matter of portraying the physics of mass movements accurately. A precise interpretation of a depositional facies (e.g., sandy slide vs. sandy debrite is vital not only for maintaining conceptual clarity but also for characterizing petroleum reservoirs.

Earthquake swarms reveal submarine magma unrest induced by distant mega-earthquakes: Andaman Sea region

Czech Academy of Sciences Publication Activity Database

Špičák, Aleš; Vaněk, Jiří

2016-01-01

Roč. 116, February (2016), s. 155-163 ISSN 1367-9120 Institutional support: RVO:67985530 Keywords : earthquake swarms * magma migration * submarine volcanic arc Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.335, year: 2016

PUREX Plant deactivation mission analysis report

International Nuclear Information System (INIS)

Lund, D.P.

1995-01-01

The purpose of the PUREX Deactivation Project mission analysis is to define the problem to be addressed by the PUREX mission, and to lay the ground work for further system definition. The mission analysis is an important first step in the System Engineering (SE) process. This report presents the results of the PUREX Deactivation Project mission analysis. The purpose of the PUREX Deactivation Project is to prepare PUREX for Decontamination and Decommissioning within a five year time frame. This will be accomplished by establishing a passively safe and environmentally secure configuration of the PUREX Plant, that can be preserved for a 10-year horizon. During deactivation, appropriate portions of the safety envelop will be maintained to ensure deactivation takes place in a safe and regulatory compliant manner

The User Community and a Multi-Mission Data Project: Services, Experiences and Directions of the Space Physics Data Facility

Science.gov (United States)

Fung, Shing F.; Bilitza, D.; Candey, R.; Chimiak, R.; Cooper, John; Fung, Shing; Harris, B.; Johnson R.; King, J.; Kovalick, T.;

Direct sampling methods for inverse elastic scattering problems

Science.gov (United States)

Ji, Xia; Liu, Xiaodong; Xi, Yingxia

2018-03-01

We consider the inverse elastic scattering of incident plane compressional and shear waves from the knowledge of the far field patterns. Specifically, three direct sampling methods for location and shape reconstruction are proposed using the different component of the far field patterns. Only inner products are involved in the computation, thus the novel sampling methods are very simple and fast to be implemented. With the help of the factorization of the far field operator, we give a lower bound of the proposed indicator functionals for sampling points inside the scatterers. While for the sampling points outside the scatterers, we show that the indicator functionals decay like the Bessel functions as the sampling point goes away from the boundary of the scatterers. We also show that the proposed indicator functionals continuously dependent on the far field patterns, which further implies that the novel sampling methods are extremely stable with respect to data error. For the case when the observation directions are restricted into the limited aperture, we firstly introduce some data retrieval techniques to obtain those data that can not be measured directly and then use the proposed direct sampling methods for location and shape reconstructions. Finally, some numerical simulations in two dimensions are conducted with noisy data, and the results further verify the effectiveness and robustness of the proposed sampling methods, even for multiple multiscale cases and limited-aperture problems.

Plutonium Finishing Plant Transition Project mission analysis report

International Nuclear Information System (INIS)

Courson, D.B.

1994-01-01

This report defines the mission for the Plutonium Finishing Plant Transition Project (PFPTP) using a systems engineering approach. This mission analysis will be the basis for the functional analysis which will further define and break down the mission statement into all of the detailed functions required to accomplish the mission. The functional analysis is then used to develop requirements, allocate those requirements to functions, and eventually be used to design the system. This report: presents the problem which will be addressed, defines PFP Transition Project, defines the overall mission statement, describes the existing, initial conditions, defines the desired, final conditions, identifies the mission boundaries and external interfaces, identifies the resources required to carry out the mission, describes the uncertainties and risks, and discusses the measures which will be used to determine success

The Gaia mission

NARCIS (Netherlands)

Collaboration, Gaia; Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri, X.; Mignard, F.; Milligan, D. J.; Panem, C.; Poinsignon, V.; Pourbaix, D.; Randich, S.; Sarri, G.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Valette, V.; van Leeuwen, F.; Walton, N. A.; Aerts, C.; Arenou, F.; Cropper, M.; Drimmel, R.; Høg, E.; Katz, D.; Lattanzi, M. G.; O'Mullane, W.; Grebel, E. K.; Holland, A. D.; Huc, C.; Passot, X.; Bramante, L.; Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Hernández, J.; Jean-Antoine-Piccolo, A.; Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Ordóñez-Blanco, D.; Panuzzo, P.; Portell, J.; Richards, P. J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Torra, J.; Els, S. G.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Lock, T.; Mercier, E.; Altmann, M.; Andrae, R.; Astraatmadja, T. L.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.; Cowell, S.; Creevey, O.; Cuypers, J.; Davidson, M.; De Ridder, J.; de Torres, A.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Frémat, Y.; García-Torres, M.; Gosset, E.; Halbwachs, J. -L; Hambly, N. C.; Harrison, D. L.; Hauser, M.; Hestroffer, D.; Hodgkin, S. T.; Huckle, H. E.; Hutton, A.; Jasniewicz, G.; Jordan, S.; Kontizas, M.; Korn, A. J.; Lanzafame, A. C.; Manteiga, M.; Moitinho, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M; Recio-Blanco, A.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Smith, K. W.; Sozzetti, A.; Thuillot, W.; van Reeven, W.; Viala, Y.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aguado, J. J.; Allan, P. M.; Allasia, W.; Altavilla, G.; Álvarez, M. A.; Alves, J.; Anderson, R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Antón, S.; Arcay, B.; Atzei, A.; Ayache, L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Barache, C.; Barata, C.; Barbier, A.; Barblan, F.; Baroni, M.; Barrado y Navascués, D.; Barros, M.; Barstow, M. A.; Becciani, U.; Bellazzini, M.; Bellei, G.; Bello García, A.; Belokurov, V.; Bendjoya, P.; Berihuete, A.; Bianchi, L.; Bienaymé, O.; Billebaud, F.; Blagorodnova, N.; Blanco-Cuaresma, S.; Boch, T.; Bombrun, A.; Borrachero, R.; Bouquillon, S.; Bourda, G.; Bouy, H.; Bragaglia, A.; Breddels, M. A.; Brouillet, N.; Brüsemeister, T.; Bucciarelli, B.; Budnik, F.; Burgess, P.; Burgon, R.; Burlacu, A.; Busonero, D.; Buzzi, R.; Caffau, E.; Cambras, J.; Campbell, H.; Cancelliere, R.; Cantat-Gaudin, T.; Carlucci, T.; Carrasco, J. M.; Castellani, M.; Charlot, P.; Charnas, J.; Charvet, P.; Chassat, F.; Chiavassa, A.; Clotet, M.; Cocozza, G.; Collins, R. S.; Collins, P.; Costigan, G.; Crifo, F.; Cross, N. J. G.; Crosta, M.; Crowley, C.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; De Cat, P.; de Felice, F.; de Laverny, P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; di Marco, F.; Di Matteo, P.; Diakite, S.; Distefano, E.; Dolding, C.; Dos Anjos, S.; Drazinos, P.; Durán, J.; Dzigan, Y.; Ecale, E.; Edvardsson, B.; Enke, H.; Erdmann, M.; Escolar, D.; Espina, M.; Evans, N. W.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Faye, F.; Federici, L.; Fedorets, G.; Fernández-Hernández, J.; Fernique, P.; Fienga, A.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fouesneau, M.; Fraile, E.; Fraser, M.; Fuchs, J.; Furnell, R.; Gai, M.; Galleti, S.; Galluccio, L.; Garabato, D.; García-Sedano, F.; Garé, P.; Garofalo, A.; Garralda, N.; Gavras, P.; Gerssen, J.; Geyer, R.; Gilmore, G.; Girona, S.; Giuffrida, G.; Gomes, M.; González-Marcos, A.; González-Núñez, J.; González-Vidal, J. J.; Granvik, M.; Guerrier, A.; Guillout, P.; Guiraud, J.; Gúrpide, A.; Gutiérrez-Sánchez, R.; Guy, L. P.; Haigron, R.; Hatzidimitriou, D.; Haywood, M.; Heiter, U.; Helmi, A.; Hobbs, D.; Hofmann, W.; Holl, B.; Holland, G.; Hunt, J. A. S.; Hypki, A.; Icardi, V.; Irwin, M.; Jevardat de Fombelle, G.; Jofré, P.; Jonker, P. G.; Jorissen, A.; Julbe, F.; Karampelas, A.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Koubsky, P.; Kowalczyk, A.; Krone-Martins, A.; Kudryashova, M.; Kull, I.; Bachchan, R. K.; Lacoste-Seris, F.; Lanza, A. F.; Lavigne, J. -B; Le Poncin-Lafitte, C.; Lebreton, Y.; Lebzelter, T.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lemaitre, V.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Löffler, W.; López, M.; Lopez-Lozano, A.; Lorenz, D.; Loureiro, T.; MacDonald, I.; Magalhães Fernandes, T.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marie, J.; Marinoni, S.; Marrese, P. M.; Marschalkó, G.; Marshall, D. J.; Martín-Fleitas, J. M.; Martino, M.; Mary, N.; Matijevič, G.; Mazeh, T.; McMillan, P. J.; Messina, S.; Mestre, A.; Michalik, D.; Millar, N. R.; Miranda, B. M. H.; Molina, D.; Molinaro, R.; Molinaro, M.; Molnár, L.; Moniez, M.; Montegriffo, P.; Monteiro, D.; Mor, R.; Mora, A.; Morbidelli, R.; Morel, T.; Morgenthaler, S.; Morley, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.; Narbonne, J.; Nelemans, G.; Nicastro, L.; Noval, L.; Ordénovic, C.; Ordieres-Meré, J.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Parsons, P.; Paulsen, T.; Pecoraro, M.; Pedrosa, R.; Pentikäinen, H.; Pereira, J.; Pichon, B.; Piersimoni, A. M.; Pineau, F. -X; Plachy, E.; Plum, G.; Poujoulet, E.; Prša, A.; Pulone, L.; Ragaini, S.; Rago, S.; Rambaux, N.; Ramos-Lerate, M.; Ranalli, P.; Rauw, G.; Read, A.; Regibo, S.; Renk, F.; Reylé, C.; Ribeiro, R. A.; Rimoldini, L.; Ripepi, V.; Riva, A.; Rixon, G.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Rudolph, A.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sarasso, M.; Savietto, H.; Schnorhk, A.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Serpell, E.; Shih, I. -C; Smareglia, R.; Smart, R. L.; Smith, C.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Süveges, M.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Tingley, B.; Trager, S. C.; Turon, C.; Ulla, A.; Utrilla, E.; Valentini, G.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Varadi, M.; Vecchiato, A.; Veljanoski, J.; Via, T.; Vicente, D.; Vogt, S.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Weingrill, K.; Werner, D.; Wevers, T.; Whitehead, G.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Zucker, S.; Zurbach, C.; Zwitter, T.; Alecu, A.; Allen, M.; Allende Prieto, C.; Amorim, A.; Anglada-Escudé, G.; Arsenijevic, V.; Azaz, S.; Balm, P.; Beck, M.; Bernstein, H. -H; Bigot, L.; Bijaoui, A.; Blasco, C.; Bonfigli, M.; Bono, G.; Boudreault, S.; Bressan, A.; Brown, S.; Brunet, P. -M; Bunclark, P.; Buonanno, R.; Butkevich, A. G.; Carret, C.; Carrion, C.; Chemin, L.; Chéreau, F.; Corcione, L.; Darmigny, E.; de Boer, K. S.; de Teodoro, P.; de Zeeuw, P. T.; Delle Luche, C.; Domingues, C. D.; Dubath, P.; Fodor, F.; Frézouls, B.; Fries, A.; Fustes, D.; Fyfe, D.; Gallardo, E.; Gallegos, J.; Gardiol, D.; Gebran, M.; Gomboc, A.; Gómez, A.; Grux, E.; Gueguen, A.; Heyrovsky, A.; Hoar, J.; Iannicola, G.; Isasi Parache, Y.; Janotto, A. -M; Joliet, E.; Jonckheere, A.; Keil, R.; Kim, D. -W; Klagyivik, P.; Klar, J.; Knude, J.; Kochukhov, O.; Kolka, I.; Kos, J.; Kutka, A.; Lainey, V.; LeBouquin, D.; Liu, C.; Loreggia, D.; Makarov, V. V.; Marseille, M. G.; Martayan, C.; Martinez-Rubi, O.; Massart, B.; Meynadier, F.; Mignot, S.; Munari, U.; Nguyen, A. -T; Nordlander, T.; Ocvirk, P.; O'Flaherty, K. S.; Olias Sanz, A.; Ortiz, P.; Osorio, J.; Oszkiewicz, D.; Ouzounis, A.; Palmer, M.; Park, P.; Pasquato, E.; Peltzer, C.; Peralta, J.; Péturaud, F.; Pieniluoma, T.; Pigozzi, E.; Poels, J.; Prat, G.; Prod'homme, T.; Raison, F.; Rebordao, J. M.; Risquez, D.; Rocca-Volmerange, B.; Rosen, S.; Ruiz-Fuertes, M. I.; Russo, F.; Sembay, S.; Serraller Vizcaino, I.; Short, A.; Siebert, A.; Silva, H.; Sinachopoulos, D.; Slezak, E.; Soffel, M.; Sosnowska, D.; Straižys, V.; ter Linden, M.; Terrell, D.; Theil, S.; Tiede, C.; Troisi, L.; Tsalmantza, P.; Tur, D.; Vaccari, M.; Vachier, F.; Valles, P.; Van Hamme, W.; Veltz, L.; Virtanen, J.; Wallut, J. -M; Wichmann, R.; Wilkinson, M. I.; Ziaeepour, H.; Zschocke, S.

2016-01-01

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by

Deciphering Depositional Signals in the Bed-Scale Stratigraphic Record of Submarine Channels

Science.gov (United States)

Sylvester, Z.; Covault, J. A.

2017-12-01

Submarine channels are important conduits of sediment transfer from rivers and shallow-marine settings into the deep sea. As such, the stratigraphic record of submarine-channel systems can store signals of past climate- and other environmental changes in their upstream sediment-source areas. This record is highly fragmented as channels are primarily locations of sediment bypass; channelized turbidity currents are likely to leave a more complete record in areas away from and above the thalweg. However, the link between the thick-bedded axial channel deposits that record a small number of flows and the much larger number of thin-bedded turbidites forming terrace- and levee deposits is poorly understood. We have developed a relatively simple two-dimensional model that, given a number of input flow parameters (mean velocity, grain size, duration of deposition, flow thickness), predicts the thickness and composition of the turbidite that is left behind in the channel and in the overbank areas. The model is based on a Rouse-type suspended sediment concentration profile and the Garcia-Parker entrainment function. In the vertical direction, turbidites tend to rapidly become thinner and finer-grained with height above thalweg, due to decreasing concentration. High near-thalweg concentrations result in thick axial beds. However, an increase in flow velocity can result in high entrainment and no deposition at the bottom of the channel, yet a thin layer of sand and mud is still deposited higher up on the channel bank. If channel thalwegs are largely in a bypass condition, relatively minor velocity fluctuations result in a few occasionally preserved thick beds in the axis, and numerous thin turbidites - and a more complete record - on the channel banks. We use near-seafloor data from the Niger Delta slope and an optimization algorithm to show how our model can be used to invert for likely flow parameters and match the bed thickness and grain size of 100 turbidites observed in a

Haines - Scagway Submarine Cable Intertie Project, Haines to Scagway, Alaska Final Technical and Construction Report

Energy Technology Data Exchange (ETDEWEB)

See, Alan; Rinehart, Bennie N; Marin, Glen

1998-11-01

The Haines to Skagway submarine cable project is located n Taiya Inlet, at the north end of Lynn Canal, in Southeast Alaska. The cable is approximately 15 miles long, with three landings and splice vaults. The cable is 35 kV, 3-Phase, and armored. The cable interconnects the Goat Lake Hydro Project near Skagway with the community of Haines. Both communities are now on 100% hydroelectric power. The Haines to Skagway submarine cable is the result of AP&T's goal of an alternative, economic, and environmentally friendly energy source for the communities served and to eliminate the use of diesel fuel as the primary source of energy. Diesel units will continue to be used as a backup system.

Lunar Exploration Missions Since 2006

Science.gov (United States)

Lawrence, S. J. (Editor); Gaddis, L. R.; Joy, K. H.; Petro, N. E.

2017-01-01

The announcement of the Vision for Space Exploration in 2004 sparked a resurgence in lunar missions worldwide. Since the publication of the first "New Views of the Moon" volume, as of 2017 there have been 11 science-focused missions to the Moon. Each of these missions explored different aspects of the Moon's geology, environment, and resource potential. The results from this flotilla of missions have revolutionized lunar science, and resulted in a profoundly new emerging understanding of the Moon. The New Views of the Moon II initiative itself, which is designed to engage the large and vibrant lunar science community to integrate the results of these missions into new consensus viewpoints, is a direct outcome of this impressive array of missions. The "Lunar Exploration Missions Since 2006" chapter will "set the stage" for the rest of the volume, introducing the planetary community at large to the diverse array of missions that have explored the Moon in the last decade. Content: This chapter will encompass the following missions: Kaguya; ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun); Chang’e-1; Chandrayaan-1; Moon Impact Probe; Lunar Reconnaissance Orbiter (LRO); Lunar Crater Observation Sensing Satellite (LCROSS); Chang’e-2; Gravity Recovery and Interior Laboratory (GRAIL); Lunar Atmosphere and Dust Environment Explorer (LADEE); Chang’e-3.

Multi-scale evaluations of submarine groundwater discharge

Directory of Open Access Journals (Sweden)

M. Taniguchi

2015-03-01

Full Text Available Multi-scale evaluations of submarine groundwater discharge (SGD have been made in Saijo, Ehime Prefecture, Shikoku Island, Japan, by using seepage meters for point scale, 222Rn tracer for point and coastal scales, and a numerical groundwater model (SEAWAT for coastal and basin scales. Daily basis temporal changes in SGD are evaluated by continuous seepage meter and 222Rn mooring measurements, and depend on sea level changes. Spatial evaluations of SGD were also made by 222Rn along the coast in July 2010 and November 2011. The area with larger 222Rn concentration during both seasons agreed well with the area with larger SGD calculated by 3D groundwater numerical simulations.

A direct sampling method to an inverse medium scattering problem

KAUST Repository

Ito, Kazufumi

2012-01-10

In this work we present a novel sampling method for time harmonic inverse medium scattering problems. It provides a simple tool to directly estimate the shape of the unknown scatterers (inhomogeneous media), and it is applicable even when the measured data are only available for one or two incident directions. A mathematical derivation is provided for its validation. Two- and three-dimensional numerical simulations are presented, which show that the method is accurate even with a few sets of scattered field data, computationally efficient, and very robust with respect to noises in the data. © 2012 IOP Publishing Ltd.

Basic targeting strategies for rendezvous and flyby missions to the near-Earth asteroids

Science.gov (United States)

Perozzi, Ettore; Rossi, Alessandro; Valsecchi, Giovanni B.

2001-01-01

Missions to asteroids and comets are becoming increasingly feasible both from a technical and a financial point of view. In particular, those directed towards the Near-Earth Asteroids have proven suitable for a low-cost approach, thus attracting the major space agencies as well as private companies. The choice of a suitable target involves both scientific relevance and mission design considerations, being often a difficult task to accomplish due to the limited energy budget at disposal. The aim of this paper is to provide an approach to basic trajectory design which allows to account for both aspects of the problem, taking into account scientific and technical information. A global characterization of the Near-Earth Asteroids population carried out on the basis of their dynamics, physical properties and flight dynamics considerations, allows to identify a group of candidates which satisfy both, the scientific and engineering requirements. The feasibility of rendezvous and flyby missions towards them is then discussed and the possibility of repeated encounters with the same object is investigated, as an intermediate scenario. Within this framework, the capability of present and near future launch and propulsion systems for interplanetary missions is also addressed.

Habitable Exoplanet Imaging Mission (HabEx): Architecture of the 4m Mission Concept

Science.gov (United States)

Kuan, Gary M.; Warfield, Keith R.; Mennesson, Bertrand; Kiessling, Alina; Stahl, H. Philip; Martin, Stefan; Shaklan, Stuart B.; amini, rashied

2018-01-01

The Habitable Exoplanet Imaging Mission (HabEx) study is tasked by NASA to develop a scientifically compelling and technologically feasible exoplanet direct imaging mission concept, with extensive general astrophysics capabilities, for the 2020 Decadal Survey in Astrophysics. The baseline architecture of this space-based observatory concept encompasses an unobscured 4m diameter aperture telescope flying in formation with a 72-meter diameter starshade occulter. This large aperture, ultra-stable observatory concept extends and enhances upon the legacy of the Hubble Space Telescope by allowing us to probe even fainter objects and peer deeper into the Universe in the same ultraviolet, visible, and near infrared wavelengths, and gives us the capability, for the first time, to image and characterize potentially habitable, Earth-sized exoplanets orbiting nearby stars. Revolutionary direct imaging of exoplanets will be undertaken using a high-contrast coronagraph and a starshade imager. General astrophysics science will be undertaken with two world-class instruments – a wide-field workhorse camera for imaging and multi-object grism spectroscopy, and a multi-object, multi-resolution ultraviolet spectrograph. This poster outlines the baseline architecture of the HabEx flagship mission concept.

Scientific Ocean Drilling Behind the Assessment of Geo-Hazards from Submarine Slides

Directory of Open Access Journals (Sweden)

Gemma Ercilla

2007-03-01

Full Text Available The workshop ‘Scientific Ocean Drilling Behind the Assessment of Geo-hazards from Submarine Slides’ was held on 25–27 October 2006 in Barcelona (Spain. Fifty mainly European scientists and industry representatives attended from a wide spectrum of disciplines such as geophysics, stratigraphy, sedimentology, paleoceanography, marinegeotechnology, geotechnical engineering, and tsunami modeling.

Navy Virginia (SSN 774) Class Attack Submarine Procurement: Background and Issues for Congress

Science.gov (United States)

2016-10-25

Implications for U.S. Navy Capabilities—Background and Issues for Congress, by Ronald O’Rourke. 45 Stephen J. Hadley and William J. Perry, co...Generally speaking, delays in maintenance periods will impact the overall operational availability of the submarine force,” Lt. Cmdr. Tim Hawkins

Event-driven sediment flux in Hueneme and Mugu submarine canyons, southern California

Science.gov (United States)

Xu, J. P.; Swarzenski, P.W.; Noble, M.; Li, A.-C.

2010-01-01

Vertical sediment fluxes and their dominant controlling processes in Hueneme and Mugu submarine canyons off south-central California were assessed using data from sediment traps and current meters on two moorings that were deployed for 6 months during the winter of 2007. The maxima of total particulate flux, which reached as high as 300+ g/m2/day in Hueneme Canyon, were recorded during winter storm events when high waves and river floods often coincided. During these winter storms, wave-induced resuspension of shelf sediment was a major source for the elevated sediment fluxes. Canyon rim morphology, rather than physical proximity to an adjacent river mouth, appeared to control the magnitude of sediment fluxes in these two submarine canyon systems. Episodic turbidity currents and internal bores enhanced sediment fluxes, particularly in the lower sediment traps positioned 30 m above the canyon floor. Lower excess 210Pb activities measured in the sediment samples collected during periods of peak total particulate flux further substantiate that reworked shelf-, rather than newly introduced river-borne, sediments supply most of the material entering these canyons during storms.

Topographic profile of a target with use of laser pulses. A survey directed to the Brazilian deep space mission ASTER

International Nuclear Information System (INIS)

De Brum, A G V; Rodrigues, A P

2013-01-01

This work is directly related to the development of the laser altimeter for the ASTER mission, named ALR. The Brazilian deep space mission ASTER plans to send a small spacecraft to encounter and investigate the triple asteroid 2001-SN263. The launch is scheduled to occur in 2017 and the ALR is now under development in partnership with UNICAMP, UFABC and aerospace companies. In this work, the environment and the operation of the instrument were modeled and simulations were carried out in order to better understand and define the instrument parameters. The creation of the simulation software to control the operation of the instrument was the main purpose of this work, and the software so far created is the main result of it. The software was successfully tested with respect to some common expected situations

Training Concept for Long Duration Space Mission

Science.gov (United States)

O'Keefe, William

2008-01-01

There has been papers about maintenance and psychological training for Long Duration Space Mission (LDSM). There are papers on the technology needed for LDSMs. Few are looking at how groundbased pre-mission training and on-board in-transit training must be melded into one training concept that leverages this technology. Even more importantly, fewer are looking at how we can certify crews pre-mission. This certification must ensure, before the crew launches, that they can handle any problem using on-board assets without a large ground support team.

Educational strategies associated with development of problem-solving, critical thinking, and self-directed learning.

Science.gov (United States)

Hendricson, William D; Andrieu, Sandra C; Chadwick, D Gregory; Chmar, Jacqueline E; Cole, James R; George, Mary C; Glickman, Gerald N; Glover, Joel F; Goldberg, Jerold S; Haden, N Karl; Meyerowitz, Cyril; Neumann, Laura; Pyle, Marsha; Tedesco, Lisa A; Valachovic, Richard W; Weaver, Richard G; Winder, Ronald L; Young, Stephen K; Kalkwarf, Kenneth L

2006-09-01

This article was developed for the Commission on Change and Innovation in Dental Education (CCI), established by the American Dental Education Association. CCI was created because numerous organizations within organized dentistry and the educational community have initiated studies or proposed modifications to the process of dental education, often working to achieve positive and desirable goals but without coordination or communication. The fundamental mission of CCI is to serve as a focal meeting place where dental educators and administrators, representatives from organized dentistry, the dental licensure community, the Commission on Dental Accreditation, the ADA Council on Dental Education and Licensure, and the Joint Commission on National Dental Examinations can meet and coordinate efforts to improve dental education and the nation's oral health. One of the objectives of the CCI is to provide guidance to dental schools related to curriculum design. In pursuit of that objective, this article summarizes the evidence related to this question: What are educational best practices for helping dental students acquire the capacity to function as an entry-level general dentist or to be a better candidate to begin advanced studies? Three issues are addressed, with special emphasis on the third: 1) What constitutes expertise, and when does an individual become an expert? 2) What are the differences between novice and expert thinking? and 3) What educational best practices can help our students acquire mental capacities associated with expert function, including critical thinking and self-directed learning? The purpose of this review is to provide a benchmark that faculty and academic planners can use to assess the degree to which their curricula include learning experiences associated with development of problem-solving, critical thinking, self-directed learning, and other cognitive skills necessary for dental school graduates to ultimately become expert performers as

Discovering the Effects-Endstate Linkage: Using Soft Systems Methodology to Perform EBO Mission Analysis

National Research Council Canada - National Science Library

Young, Jr, William E

2005-01-01

.... EBO mission analysis is shown to be more problem structuring than problem solving. A new mission analysis process is proposed using a modified version of Soft Systems Methodology to meet these challenges...

The timing of sediment transport down Monterey Submarine Canyon, offshore California

Science.gov (United States)

Stevens, Thomas; Paull, Charles K.; Ussler, William III; McGann, Mary; Buylaert, Jan-Pieter; Lundsten, Eve M.

2013-01-01

While submarine canyons are the major conduits through which sediments are transported from the continents out into the deep sea, the time it takes for sediment to pass down through a submarine canyon system is poorly constrained. Here we report on the first study to couple optically stimulated luminescence (OSL) ages of quartz sand deposits and accelerator mass spectrometry 14C ages measured on benthic foraminifera to examine the timing of sediment transport through the axial channel of Monterey Submarine Canyon and Fan, offshore California. The OSL ages date the timing of sediment entry into the canyon head while the 14C ages of benthic foraminifera record the deposition of hemipelagic sediments that bound the sand horizons. We use both single-grain and small (∼2 mm area) single-aliquot regeneration approaches on vibracore samples from fining-upward sequences at various water depths to demonstrate relatively rapid, decadal-scale sand transport to at least 1.1 km depth and more variable decadal- to millennial-scale transport to a least 3.5 km depth on the fan. Significant differences between the time sand was last exposed at the canyon head (OSL age) and the timing of deposition of the sand (from 14C ages of benthic foraminifera in bracketing hemipelagic sediments) are interpreted as indicating that the sand does not pass through the entire canyon instantly in large individual events, but rather moves multiple times before emerging onto the fan. The increased spread in single-grain OSL dates with water depth provides evidence of mixing and temporary storage of sediment as it moves through the canyon system. The ages also indicate that the frequency of sediment transport events decreases with distance down the canyon channel system. The amalgamated sands near the canyon head yield OSL ages that are consistent with a sub-decadal recurrence frequency while the fining-upward sand sequences on the fan indicate that the channel is still experiencing events with a 150�

Rendezvous missions with minimoons from L1

Science.gov (United States)

Chyba, M.; Haberkorn, T.; Patterson, G.

2014-07-01

) with the spacecraft. This is determined using a combination of distance between the minimoon's orbit to L1 and its energy level with respect to the Lissajoux orbit on which the spacecraft is hibernating. Once the spacecraft rendezvous with the minimoon, it will escort the temporarily captured object to analyze it until the withdrawal time when the spacecraft exits the orbit to return to its hibernating location awaiting for another minimoon to be detected. The entire mission including the return portion can be stated as an optimal control problem, however we choose to break it into smaller sub-problems as a first step to be refined later. To model our control system, we use the circular three-body problem since it provides a good approximation in the vicinity of the Earth-Moon dynamics. Expansion to more refined models will be considered once the problem has been solved for this first approximation. The problem is solved in several steps. First, we consider the time minimal problem since we will use a multiple of it for the minimal fuel consumption problem with fixed time. The techniques used to produce the transfers involve an indirect method based on the necessary optimality condition of the Pontriagyn maximum principle coupled with a continuation method to address the sensitivity of the numerical algorithm to initial values. Time local optimality is verified by computing the Jacobi fields of the Hamiltonian system associated to our optimal control problem to check the second-order conditions of optimality and determine the non-existence of conjugate points.

A three-dimensional stratigraphic model for aggrading submarine channels based on laboratory experiments, numerical modeling, and sediment cores

Science.gov (United States)

Limaye, A. B.; Komatsu, Y.; Suzuki, K.; Paola, C.

2017-12-01

Turbidity currents deliver clastic sediment from continental margins to the deep ocean, and are the main driver of landscape and stratigraphic evolution in many low-relief, submarine environments. The sedimentary architecture of turbidites—including the spatial organization of coarse and fine sediments—is closely related to the aggradation, scour, and lateral shifting of channels. Seismic stratigraphy indicates that submarine, meandering channels often aggrade rapidly relative to lateral shifting, and develop channel sand bodies with high vertical connectivity. In comparison, the stratigraphic architecture developed by submarine, braided is relatively uncertain. We present a new stratigraphic model for submarine braided channels that integrates predictions from laboratory experiments and flow modeling with constraints from sediment cores. In the laboratory experiments, a saline density current developed subaqueous channels in plastic sediment. The channels aggraded to form a deposit with a vertical scale of approximately five channel depths. We collected topography data during aggradation to (1) establish relative stratigraphic age, and (2) estimate the sorting patterns of a hypothetical grain size distribution. We applied a numerical flow model to each topographic surface and used modeled flow depth as a proxy for relative grain size. We then conditioned the resulting stratigraphic model to observed grain size distributions using sediment core data from the Nankai Trough, offshore Japan. Using this stratigraphic model, we establish new, quantitative predictions for the two- and three-dimensional connectivity of coarse sediment as a function of fine-sediment fraction. Using this case study as an example, we will highlight outstanding challenges in relating the evolution of low-relief landscapes to the stratigraphic record.

Taking a Dive for a Friend - The Decision to Transfer Nuclear Submarine Technology to Canada

National Research Council Canada - National Science Library

Brubaker, Gerald L

1990-01-01

.... national security bureaucracy: President Reagan had approved the transfer of U.S.-developed nuclear submarine propulsion technology to Canada and would inform Prime Minister Brian Mulroney during his visit to Washington later that month...

Applications of nuclear reactor power systems to electric propulsion missions.

Science.gov (United States)

Schaupp, R. W.; Sawyer, C. D.

1971-01-01

The performance of nuclear electric propulsion systems (NEP) has been evaluated for a wide variety of missions in an attempt to establish the commonality of NEP system requirements. Emphasis was given to those requirements and system characteristics that serve as guidelines for current technology development programs. Various interactions and tradeoffs between NEP system and mission parameters are described. The results show that the most significant factors in selecting NEP system size are launch mode (direct or spiral escape) and, to a weaker extent, launch vehicle capability. Other factors such as mission, payload, and thrust time constraints, have little influence, thus allowing one NEP system to be used for many missions. The results indicated that a 100 kWe NEP would be suitable for most direct escape missions and a 250 kWe NEP system would be suitable for more demanding missions that use the spiral escape mode.

Self-directed learning readiness of Asian students: students perspective on a hybrid problem based learning curriculum.

Science.gov (United States)

Leatemia, Lukas D; Susilo, Astrid P; van Berkel, Henk

2016-12-03

To identify the student's readiness to perform self-directed learning and the underlying factors influencing it on the hybrid problem based learning curriculum. A combination of quantitative and qualitative studies was conducted in five medical schools in Indonesia. In the quantitative study, the Self Directed Learning Readiness Scale was distributed to all students in all batches, who had experience with the hybrid problem based curriculum. They were categorized into low- and high -level based on the score of the questionnaire. Three focus group discussions (low-, high-, and mixed level) were conducted in the qualitative study with six to twelve students chosen randomly from each group to find the factors influencing their self-directed learning readiness. Two researchers analysed the qualitative data as a measure of triangulation. The quantitative study showed only half of the students had a high-level of self-directed learning readiness, and a similar trend also occurred in each batch. The proportion of students with a high level of self-directed learning readiness was lower in the senior students compared to more junior students. The qualitative study showed that problem based learning processes, assessments, learning environment, students' life styles, students' perceptions of the topics, and mood, were factors influencing their self-directed learning. A hybrid problem based curriculum may not fully affect the students' self-directed learning. The curriculum system, teacher's experiences, student's background and cultural factors might contribute to the difficulties for the student's in conducting self-directed learning.

Production logistic for an attack nuclear submarine squadron fuel

International Nuclear Information System (INIS)

Guimaraes, Leonam dos Santos

1999-01-01

The future acquisition of nuclear attack submarines by Brazilian Navy along next century will imply new requirements on Naval Logistic Support System. These needs will impact all the six logistic functions. Among them, fuel supply could be considered as the one which requires the most important capacitating effort, including not only technological development of processes but also the development of a national industrial basis for effective production of nuclear fuel. This paper presents the technical aspects of the processes involved and an annual production dimensioning for an squadron composed by four units. (author)

Biological life-support systems for Mars mission.

Science.gov (United States)

Gitelson, J I

1992-01-01

Mars mission like the Lunar base is the first venture to maintain human life beyond earth biosphere. So far, all manned space missions including the longest ones used stocked reserves and can not be considered egress from biosphere. Conventional path proposed by technology for Martian mission LSS is to use physical-chemical approaches proved by the experience of astronautics. But the problem of man living beyond the limits of the earth biosphere can be fundamentally solved by making a closed ecosystem for him. The choice optimum for a Mars mission LSS can be substantiated by comparing the merits and demerits of physical-chemical and biological principles without ruling out possible compromise between them. The work gives comparative analysis of ecological and physical-chemical principles for LSS. Taking into consideration universal significance of ecological problems with artificial LSS as a particular case of their solution, complexity and high cost of large-scale experiments with manned LSS, it would be expedient for these works to have the status of an International Program open to be joined. A program of making artificial biospheres based on preceding experience and analysis of current situation is proposed.

Norwegian monitoring (1990-2015) of the marine environment around the sunken nuclear submarine Komsomolets.

Science.gov (United States)

Gwynn, Justin P; Heldal, Hilde Elise; Flo, Janita K; Sværen, Ingrid; Gäfvert, Torbjörn; Haanes, Hallvard; Føyn, Lars; Rudjord, Anne Liv

2018-02-01

Norway has monitored the marine environment around the sunken Russian nuclear submarine Komsomolets since 1990. This study presents an overview of 25 years of Norwegian monitoring data (1990-2015). Komsomolets sank in 1989 at a depth of 1680 m in the Norwegian Sea while carrying two nuclear torpedoes in its armament. Subsequent Soviet and Russian expeditions to Komsomolets have shown that releases from the reactor have occurred and that the submarine has suffered considerable damage to its hulls. Norwegian monitoring detected 134 Cs in surface sediments around Komsomolets in 1993 and 1994 and elevated activity concentrations of 137 Cs in bottom seawater between 1991 and 1993. Since then and up to 2015, no increased activity concentrations of radionuclides above values typical for the Norwegian Sea have been observed in any environmental sample collected by Norwegian monitoring. In 2013 and 2015, Norwegian monitoring was carried out using an acoustic transponder on the sampling gear that allowed samples to be collected at precise locations, ∼20 m from the hull of Komsomolets. The observed 238 Pu/ 239,240 Pu activity ratios and 240 Pu/ 239 Pu atom ratios in surface sediments sampled close to Komsomolets in 2013 did not indicate any releases of Pu isotopes from reactor or the torpedo warheads. Rather, these values probably reflect the overprinting of global fallout ratios with fluxes of these Pu isotopes from long-range transport of authorised discharges from nuclear reprocessing facilities in Northern Europe. However, due to the depth at which Komsomolets lies, the collection of seawater and sediment samples in the immediate area around the submarine using traditional sampling techniques from surface vessels is not possible, even with the use of acoustic transponders. Further monitoring is required in order to have a clear understanding of the current status of Komsomolets as a potential source of radioactive contamination to the Norwegian marine environment

Geomorphic Thresholds of Submarine Canyons Along the U.S. Atlantic Continental Margin

Science.gov (United States)

Brothers, D. S.; ten Brink, U. S.; Andrews, B. D.; Chaytor, J. D.

2011-12-01

Vast networks of submarine canyons and associated channels are incised into the U.S. Atlantic continental slope and rise. Submarine canyons form by differential erosion and deposition, primarily from sedimentary turbidity flows. Theoretical and laboratory studies have investigated the initiation of turbidity flows and their capacity to erode and entrain sedimentary material at distances far from the shelf edge. The results have helped understand the nature of turbidite deposits on the continental slope and rise. Nevertheless, few studies have examined the linkages between down-canyon sediment transport and the morphology of canyon/channel networks using mesoscale analyses of swath bathymetry data. We present quantitative analysis of 100-m resolution multibeam bathymetry data spanning ~616,000 km2 of the slope and rise between Georges Banks and the Blake Plateau (New England to North Carolina). Canyons are categorized as shelf-indenting or slope-confined based on spatial scale, vertical relief and connection with terrestrial river systems during sea level low stands. Shelf-indenting canyons usually represent the trunk-canyon of submerged channel networks. On the rise, shelf-indenting canyons have relatively well-developed channel-levees and sharp inner-thalwag incision suggesting much higher frequency and volume of turbidity flows. Because of the similarities between submarine canyon networks and terrestrial river systems, we apply methods originally developed to study fluvial morphology. Along-canyon profiles are extracted from the bathymetry data and the power-law relationship between thalwag gradient and drainage area is examined for more than 180 canyons along an ~1200 km stretch of the US Atlantic margin. We observe distinct thresholds in the power-law relationship between drainage area and gradient. Almost all canyons with heads on the upper slope contain at least two linear segments when plotted in log-log form. The first segment along the upper slope is flat

Rapid Preliminary Design of Interplanetary Trajectories Using the Evolutionary Mission Trajectory Generator

Science.gov (United States)

Englander, Jacob

2016-01-01

Preliminary design of interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated. This can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on notional high-thrust chemical and low-thrust electric propulsion missions. In the low-thrust case, the hybrid optimal control problem is augmented to include systems design optimization.

A perspective on direct conversion

Energy Technology Data Exchange (ETDEWEB)

Lewis, W. B.

1963-10-15

As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

A perspective on direct conversion

International Nuclear Information System (INIS)

Lewis, W.B.

1963-10-01

As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

Logistics Reduction Technologies for Exploration Missions

Science.gov (United States)

Broyan, James L., Jr.; Ewert, Michael K.; Fink, Patrick W.

2014-01-01

Human exploration missions under study are limited by the launch mass capacity of existing and planned launch vehicles. The logistical mass of crew items is typically considered separate from the vehicle structure, habitat outfitting, and life support systems. Although mass is typically the focus of exploration missions, due to its strong impact on launch vehicle and habitable volume for the crew, logistics volume also needs to be considered. NASA's Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project is developing six logistics technologies guided by a systems engineering cradle-to-grave approach to enable after-use crew items to augment vehicle systems. Specifically, AES LRR is investigating the direct reduction of clothing mass, the repurposing of logistical packaging, the use of autonomous logistics management technologies, the processing of spent crew items to benefit radiation shielding and water recovery, and the conversion of trash to propulsion gases. Reduction of mass has a corresponding and significant impact to logistical volume. The reduction of logistical volume can reduce the overall pressurized vehicle mass directly, or indirectly benefit the mission by allowing for an increase in habitable volume during the mission. The systematic implementation of these types of technologies will increase launch mass efficiency by enabling items to be used for secondary purposes and improve the habitability of the vehicle as mission durations increase. Early studies have shown that the use of advanced logistics technologies can save approximately 20 m(sup 3) of volume during transit alone for a six-person Mars conjunction class mission.

Variational methods for direct/inverse problems of atmospheric dynamics and chemistry

Science.gov (United States)

Penenko, Vladimir; Penenko, Alexey; Tsvetova, Elena

2013-04-01

We present a variational approach for solving direct and inverse problems of atmospheric hydrodynamics and chemistry. It is important that the accurate matching of numerical schemes has to be provided in the chain of objects: direct/adjoint problems - sensitivity relations - inverse problems, including assimilation of all available measurement data. To solve the problems we have developed a new enhanced set of cost-effective algorithms. The matched description of the multi-scale processes is provided by a specific choice of the variational principle functionals for the whole set of integrated models. Then all functionals of variational principle are approximated in space and time by splitting and decomposition methods. Such approach allows us to separately consider, for example, the space-time problems of atmospheric chemistry in the frames of decomposition schemes for the integral identity sum analogs of the variational principle at each time step and in each of 3D finite-volumes. To enhance the realization efficiency, the set of chemical reactions is divided on the subsets related to the operators of production and destruction. Then the idea of the Euler's integrating factors is applied in the frames of the local adjoint problem technique [1]-[3]. The analytical solutions of such adjoint problems play the role of integrating factors for differential equations describing atmospheric chemistry. With their help, the system of differential equations is transformed to the equivalent system of integral equations. As a result we avoid the construction and inversion of preconditioning operators containing the Jacobi matrixes which arise in traditional implicit schemes for ODE solution. This is the main advantage of our schemes. At the same time step but on the different stages of the "global" splitting scheme, the system of atmospheric dynamic equations is solved. For convection - diffusion equations for all state functions in the integrated models we have developed the

Direct UV/Optical Imaging of Stellar Surfaces: The Stellar Imager (SI) Vision Mission

Science.gov (United States)

Carpenter, Kenneth G.; Lyon, Richard G.; Schrijver, Carolus; Karovska, Margarita; Mozurkewich, David

2007-01-01

The Stellar Imager (SI) is a UV/optical, space-based interferometer designed to enable 0.1 milli-arcsecond (mas) spectral imaging of stellar surfaces and, via asteroseismology, stellar interiors and of the Universe in general. SI's science focuses on the role of magnetism in the Universe, particularly on magnetic activity on the surfaces of stars like the Sun. SI's prime goal is to enable long-term forecasting of solar activity and the space weather that it drives, in support of the Living with a Star program in the Exploration Era. SI will also revolutionize our understanding of the formation of planetary systems, of the habitability and climatology of distant planets, and of many magneto-hydrodynamically controlled processes in thc Universe. SI is a "Flagship and Landmark Discovery Mission" in the 2005 Sun Solar System Connection (SSSC) Roadmap and a candidate for a "Pathways to Life Observatory" in the Exploration of the Universe Division (EUD) Roadmap. We discuss herein the science goals of the SI Mission, a mission architecture that could meet those goals, and the technologies needed to enable this mission. Additional information on SI can be found at: http://hires.gsfc.nasa.gov/si/.

Numerical Modelling of Tsunami Generated by Deformable Submarine Slides: Parameterisation of Slide Dynamics for Coupling to Tsunami Propagation Model

Science.gov (United States)

Smith, R. C.; Collins, G. S.; Hill, J.; Piggott, M. D.; Mouradian, S. L.

2015-12-01

Numerical modelling informs risk assessment of tsunami generated by submarine slides; however, for large-scale slides modelling can be complex and computationally challenging. Many previous numerical studies have approximated slides as rigid blocks that moved according to prescribed motion. However, wave characteristics are strongly dependent on the motion of the slide and previous work has recommended that more accurate representation of slide dynamics is needed. We have used the finite-element, adaptive-mesh CFD model Fluidity, to perform multi-material simulations of deformable submarine slide-generated waves at real world scales for a 2D scenario in the Gulf of Mexico. Our high-resolution approach represents slide dynamics with good accuracy, compared to other numerical simulations of this scenario, but precludes tracking of wave propagation over large distances. To enable efficient modelling of further propagation of the waves, we investigate an approach to extract information about the slide evolution from our multi-material simulations in order to drive a single-layer wave propagation model, also using Fluidity, which is much less computationally expensive. The extracted submarine slide geometry and position as a function of time are parameterised using simple polynomial functions. The polynomial functions are used to inform a prescribed velocity boundary condition in a single-layer simulation, mimicking the effect the submarine slide motion has on the water column. The approach is verified by successful comparison of wave generation in the single-layer model with that recorded in the multi-material, multi-layer simulations. We then extend this approach to 3D for further validation of this methodology (using the Gulf of Mexico scenario proposed by Horrillo et al., 2013) and to consider the effect of lateral spreading. This methodology is then used to simulate a series of hypothetical submarine slide events in the Arctic Ocean (based on evidence of historic

Parts Quality Management: Direct Part Marking of Data Matrix Symbol for Mission Assurance

Science.gov (United States)

Moss, Chantrice; Chakrabarti, Suman; Scott, David W.

2013-01-01

A United States Government Accountability Office (GAO) review of twelve NASA programs found widespread parts quality problems contributing to significant cost overruns, schedule delays, and reduced system reliability. Direct part marking with Data Matrix symbols could significantly improve the quality of inventory control and parts lifecycle management. This paper examines the feasibility of using direct part marking technologies for use in future NASA programs. A structural analysis is based on marked material type, operational environment (e.g., ground, suborbital, Low Earth Orbit), durability of marks, ease of operation, reliability, and affordability. A cost-benefits analysis considers marking technology (label printing, data plates, and direct part marking) and marking types (two-dimensional machine-readable, human-readable). Previous NASA parts marking efforts and historical cost data are accounted for, including inhouse vs. outsourced marking. Some marking methods are still under development. While this paper focuses on NASA programs, results may be applicable to a variety of industrial environments.

Analysis of critical thinking ability in direct current electrical problems solving

Science.gov (United States)

Hartono; Sunarno, Widha; Sarwanto; Arya Nugraha, Dewanta

2017-11-01

This study concern on analyzing the ability of students in critical thinking skills on the subject matter of direct current electricity. Samples were taken using purposive random sampling consisted of 32 students of grade XI, Multimedia 1, SMK Negeri 3 Surakarta in academic year 2016/2017. This study used descriptive quantitative method. The data were collected using tests and interviews regarding the subject matter of direct current electricity. Based on the results, students are getting some difficulties in solving problem in indicator 4. The average of students’ correct answer is 62.8%.

Potential radiological impact assessment related to the visit of nuclear submarines to the port of Rio de Janeiro, Brazil

International Nuclear Information System (INIS)

Pereira, Jose Francisco; Rochedo, Elaine R.R.

2005-01-01

Brazil is signatory of international protocols for receiving the visit of nuclear ships and submarines. Such naval units, during their stays in Brazilian ports, inform that there is no release of radioactive material to the environment. However, there is always the possibility of an accident, leading to environmental release of radioactive material. This work had the objective of assessing the potential radiological environmental impact due to the eventual occurrence of an accident during the permanence of ships and submarines of nuclear propulsion in the port of the city of Rio de Janeiro, in Guanabara Bay. The accident scenarios considered include releases to the marine environment and to the atmosphere. Previous results indicated that, in normal operation conditions, no significant radiological impact is foreseen due to the visits of nuclear submarines to the city, even if small routine radionuclide releases occur. The analysis of the accidental releases, however, indicates that the anchorage points should be located at a minimum distance of 2,5 km of inhabited areas in the contour the Bay. (author)

Estimations of radiation characteristics of spent fuel in reactors of nuclear submarines and the ice-breaker Lenin dumped near Novaya Zemlya

International Nuclear Information System (INIS)

Rubtsov, P.M.; Ruzhanskij, P.A.

1996-01-01

Calculations of radionuclide composition and radiation characteristics of actinides and fission products for the reactor spent nuclear fuel of the nuclear submarines and the ice-breaker Lenin dumped near Novaya Zemlya are calculated on the basis of the actual data on the regimes of operation of the above reactors. It is determined that the maximum total activity in 1995 in all reactor sections of the nuclear submarines is concentrated in the fuel (M = 261.9 kg, W = 2.75 GW x day) of the left reactor of the nuclear submarine APL-285 and constitutes 51.9 Ci for actinides and 1.68 x 10 4 Ci for fission products. The corresponding values for the dumped fuel (M = 856 kg, W = 14.2 GW x day) of the ice-breaker Lenin are equal to 3.9 x 10 3 and 5.22 x 10 4 Ci

Study 2.6 operations analysis mission characterization

Science.gov (United States)

Wolfe, R. R.

1973-01-01

An analysis of the current operations concepts of NASA and DoD is presented to determine if alternatives exist which may improve the utilization of resources. The final product is intended to show how sensitive these ground rules and design approaches are relative to the total cost of doing business. The results are comparative in nature, and assess one concept against another as opposed to establishing an absolute cost value for program requirements. An assessment of the mission characteristics is explained to clarify the intent, scope, and direction of this effort to improve the understanding of what is to be accomplished. The characterization of missions is oriented toward grouping missions which may offer potential economic benefits by reducing overall program costs. Program costs include design, development, testing, and engineering, recurring unit costs for logistic vehicles, payload costs. and direct operating costs.

Marine electrical resistivity imaging of submarine groundwater discharge: Sensitivity analysis and application in Waquoit Bay, Massachusetts, USA

Science.gov (United States)

Henderson, Rory; Day-Lewis, Frederick D.; Abarca, Elena; Harvey, Charles F.; Karam, Hanan N.; Liu, Lanbo; Lane, John W.

2010-01-01

Electrical resistivity imaging has been used in coastal settings to characterize fresh submarine groundwater discharge and the position of the freshwater/salt-water interface because of the relation of bulk electrical conductivity to pore-fluid conductivity, which in turn is a function of salinity. Interpretation of tomograms for hydrologic processes is complicated by inversion artifacts, uncertainty associated with survey geometry limitations, measurement errors, and choice of regularization method. Variation of seawater over tidal cycles poses unique challenges for inversion. The capabilities and limitations of resistivity imaging are presented for characterizing the distribution of freshwater and saltwater beneath a beach. The experimental results provide new insight into fresh submarine groundwater discharge at Waquoit Bay National Estuarine Research Reserve, East Falmouth, Massachusetts (USA). Tomograms from the experimental data indicate that fresh submarine groundwater discharge may shut down at high tide, whereas temperature data indicate that the discharge continues throughout the tidal cycle. Sensitivity analysis and synthetic modeling provide insight into resolving power in the presence of a time-varying saline water layer. In general, vertical electrodes and cross-hole measurements improve the inversion results regardless of the tidal level, whereas the resolution of surface arrays is more sensitive to time-varying saline water layer.

Eddy current imaging. Simplifying the direct problem. Analysis of a 2D case with formulations

International Nuclear Information System (INIS)

Spineanu, A.; Zorgati, R.

1995-01-01

Eddy current non-destructive testing is used by EDF to detect faults affecting conductive objects such as steam generator tubes. A new technique, known as eddy current imaging, is being developed to facilitate diagnosis in this context. The first stage in this work, discussed in the present paper, consists in solving the direct problem. This entails determining the measurable quantities, on the basis of a thorough knowledge of the material considered. This was done by formulating the direct problem in terms of eddy currents in general 3D geometry context, applying distribution theory and Maxwell equations. Since no direct problem code was available we resorted to simplified situations. Taking care not to interfere with previous developments or those to be attempted in an inversion context, we studied the case of a flaw affecting a 2D structure, illuminated by a plane wave type probe. For this configuration, we studied the exact model and compared results with those of a linearized simplified model. This study emphasizes the ill-posed situation of the eddy current inverse problem related with the severe electromagnetic field attenuation. This means that regularization of the inverse problem, although absolutely necessary, will not be sufficient. Owing to the simplicity of the models available and implemented during the inversion process, processing real data would not yet be possible. We must first focus all our efforts on the direct 3 D problem, in conformity with the requirements of the inverse procedure ad describing a realistic eddy current NDT situation. At the same time, consideration should be given to the design of a specific probe customized for eddy current imaging. (authors). 9 refs., 5 figs., 3 appends

Mathematical Modeling and Kinematics Analysis of Double Spherical Shell Rotary Docking Skirt

Directory of Open Access Journals (Sweden)

Gong Haixia

2017-01-01

Full Text Available In order to solve the problem of large trim and heel angles of the wrecked submarine, the double spherical shell rotating docking skirt is studied. According to the working principle of the rotating docking skirt, and the fixed skirt, the directional skirt, the angle skirt are simplified as the connecting rod. Therefore, the posture equation and kinematics model of the docking skirt are deduced, and according to the kinematics model, the angle of rotation of the directional skirt and the angle skirt is obtained when the wrecked submarine is in different trim and heel angles. Through the directional skirt and angle skirt with the matching rotation can make docking skirt interface in the 0°~2γ range within the rotation, to complete the docking skirt and the wrecked submarine docking. The MATLAB software is used to visualize the rotation angle of fixed skirt and directional skirt, which lays a good foundation for the development of the control of the double spherical shell rotating docking skirt in future.

Seasonal pathways of organic matter within the Avilés submarine canyon: Foodweb implications

NARCIS (Netherlands)

Romero-Romero, S.; Molina-Ramírez, A.; Höfer, J.; Duineveld, G.C.A.; Rumín-Caparrós, A.; Sanchez-Vidal, A.; Canals, M.; Acuña, J.L.

2016-01-01

The transport and fate of organic matter (OM) sources within the Avilés submarine canyon (Cantabrian Sea, Southern Bay of Biscay) were studied using carbon and nitrogen stable isotope ratios. The isotopic composition of settling particles and deep bottom sediments closely resembled that of surface

Experimental and Numerical Investigation of Local Scour Around Submarine Piggyback Pipeline Under Steady Current

Science.gov (United States)

Zhao, Enjin; Shi, Bing; Qu, Ke; Dong, Wenbin; Zhang, Jing

2018-04-01

As a new type of submarine pipeline, the piggyback pipeline has been gradually adopted in engineering practice to enhance the performance and safety of submarine pipelines. However, limited simulation work and few experimental studies have been published on the scour around the piggyback pipeline under steady current. This study numerically and experimentally investigates the local scour of the piggyback pipe under steady current. The influence of prominent factors such as pipe diameter, inflow Reynolds number, and gap between the main and small pipes, on the maximum scour depth have been examined and discussed in detail. Furthermore, one formula to predict the maximum scour depth under the piggyback pipeline has been derived based on the theoretical analysis of scour equilibrium. The feasibility of the proposed formula has been effectively calibrated by both experimental data and numerical results. The findings drawn from this study are instructive in the future design and application of the piggyback pipeline.

Relation of submarine landslide to hydrate occurrences in Baiyun Depression, South China Sea

Science.gov (United States)

Sun, Yunbao; Zhang, Xiaohua; Wu, Shiguo; Wang, Lei; Yang, Shengxiong

2018-02-01

Submarine landslides have been observed in the Baiyun Depression of the South China Sea. The occurrence of hydrates below these landslides indicates that these slope instabilities may be closely related to the massive release of methane. In this study, we used a simple Monte-Carlo model to determine the first-order deformation pattern of a gravitationally destabilizing slope. The results show that a stress concentration occurs due to hydrate dissociation on the nearby glide surface and on top of a gas chimney structure. Upon the dissolution of the gas hydrate, slope failure occurs due to the excess pore pressure generated by the dissociation of the gas hydrates. When gas hydrates dissociate at shallow depths, the excess pore pressure generated can be greater than the total stress acting at those points, along with the forces that resist sliding. Initially, the failure occurs at the toe of the slope, then extends to the interior. Although our investigation focused only on the contribution of hydrate decomposition to submarine landslide, this process is also affected by both the slope material properties and topography.

The Revolutionary Armed Forces of Colombia (FARC and the Development of Narco-Submarines

Directory of Open Access Journals (Sweden)

Michelle Jacome Jaramillo

2016-03-01

Full Text Available The Revolutionary Armed Forces of Colombia (FARC have been one of the world's most consistently formidable violent non-state actors over the last forty years. Unsurprisingly, the group has provided one of the most compelling and concerning examples of the level of technical sophistication attainable by sub-state organizations. Over the last two decades the group has carried out an iterative and innovative process that, in reaction to improved detection capabilities, has brought them from depending on disposable go-fast boats to transport drugs to possessing fully submersible and reusable covert vessels for transportation. The following case study will discuss the development of narco-submarines and the underlying motivations behind the pursuit of this complex engineering task. The case study will outline the different phases of the narco-submarine development and highlight FARC’s determination to overcome the challenges present in each design. This discussion will show how FARC’s systematized acquiring of information and expertise has resulted in the accomplishment of fully submersible vessels, capable of transporting more than 10 tons of illicit product.

Surface and Bottom Boundar Layer Dynamics on a Shallow Submarine Bank: Southern Flank of Georges Bank

National Research Council Canada - National Science Library

Werner, Sandra

1999-01-01

The thesis investigates the circulation at a 75-meter deep study site on the southern flank of Georges Bank, a shallow submarine bank located between the deeper Gulf of Maine and the continental slope...

Shallow methane hydrate system controls ongoing, downslope sediment transport in a low-velocity active submarine landslide complex, Hikurangi Margin, New Zealand

Science.gov (United States)

Mountjoy, Joshu J.; Pecher, Ingo; Henrys, Stuart; Crutchley, Gareth; Barnes, Philip M.; Plaza-Faverola, Andreia

2014-11-01

Morphological and seismic data from a submarine landslide complex east of New Zealand indicate flow-like deformation within gas hydrate-bearing sediment. This "creeping" deformation occurs immediately downslope of where the base of gas hydrate stability reaches the seafloor, suggesting involvement of gas hydrates. We present evidence that, contrary to conventional views, gas hydrates can directly destabilize the seafloor. Three mechanisms could explain how the shallow gas hydrate system could control these landslides. (1) Gas hydrate dissociation could result in excess pore pressure within the upper reaches of the landslide. (2) Overpressure below low-permeability gas hydrate-bearing sediments could cause hydrofracturing in the gas hydrate zone valving excess pore pressure into the landslide body. (3) Gas hydrate-bearing sediment could exhibit time-dependent plastic deformation enabling glacial-style deformation. We favor the final hypothesis that the landslides are actually creeping seafloor glaciers. The viability of rheologically controlled deformation of a hydrate sediment mix is supported by recent laboratory observations of time-dependent deformation behavior of gas hydrate-bearing sands. The controlling hydrate is likely to be strongly dependent on formation controls and intersediment hydrate morphology. Our results constitute a paradigm shift for evaluating the effect of gas hydrates on seafloor strength which, given the widespread occurrence of gas hydrates in the submarine environment, may require a reevaluation of slope stability following future climate-forced variation in bottom-water temperature.

Tectonic activity and the evolution of submarine canyons: The Cook Strait Canyon system, New Zealand

Science.gov (United States)

Micallef, Aaron; Mountjoy, Joshu; Barnes, Philip; Canals, Miquel; Lastras, Galderic

2016-04-01

Submarine canyons are Earth's most dramatic erosional features, comprising steep-walled valleys that originate in the continental shelf and slope. They play a key role in the evolution of continental margins by transferring sediments into deep water settings and are considered important biodiversity hotspots, pathways for nutrients and pollutants, and analogues of hydrocarbon reservoirs. Although comprising only one third of continental margins worldwide, active margins host more than half of global submarine canyons. We still lack of thorough understanding of the coupling between active tectonics and submarine canyon processes, which is necessary to improve the modelling of canyon evolution in active margins and derive tectonic information from canyon morphology. The objectives of this study are to: (i) understand how tectonic activity influences submarine canyon morphology, processes, and evolution in an active margin, and (2) formulate a generalised model of canyon development in response to tectonic forcing based on morphometric parameters. We fulfil these objectives by analysing high resolution geophysical data and imagery from Cook Strait Canyon system, offshore New Zealand. Using these data, we demonstrate that tectonic activity, in the form of major faults and structurally-generated tectonic ridges, leaves a clear topographic signature on submarine canyon location and morphology, in particular their dendritic and sinuous planform shapes, steep and linear longitudinal profiles, and cross-sectional asymmetry and width. We also report breaks/changes in canyon longitudinal slope gradient, relief and slope-area regression models at the intersection with faults. Tectonic activity gives rise to two types of knickpoints in the Cook Strait Canyon. The first type consists of low slope gradient, rounded and diffusive knickpoints forming as a result of short wavelength folds or fault break outs and being restored to an equilibrium profile by upstream erosion and

Structured Parent-Child Observations Predict Development of Conduct Problems: the Importance of Parental Negative Attention in Child-Directed Play.

Science.gov (United States)

Fleming, Andrew P; McMahon, Robert J; King, Kevin M

2017-04-01

Structured observations of parent-child interactions are commonly used in research and clinical settings, but require additional empirical support. The current study examined the capacity of child-directed play, parent-directed play, and parent-directed chore interaction analogs to uniquely predict the development of conduct problems across a 6-year follow-up period. Parent-child observations were collected from 338 families from high-risk neighborhoods during the summer following the child's first-grade year. Participating children were 49.2 % female, 54.4 % white, and 45.6 % black, and had an average age of 7.52 years at the first assessment. Conduct problems were assessed via parent report and teacher report at five assessment points between first grade and seventh grade. Latent growth curve modeling was used to analyze predictors of conduct problem trajectory across this 6-year follow-up period. When race, sex, socioeconomic status, and maternal depressive symptoms were controlled, parental negative attention during child-directed play predicted higher levels of parent-reported conduct problems concurrently and after a 6-year follow-up period. Parental negative attention during child-directed play also predicted higher teacher-reported conduct problems 6 years later. Findings support the use of child-directed play and parent-directed chore analogs in predicting longitudinal development of conduct problems. The presence of parental negative attention during child-directed play appears to be an especially important predictor of greater conduct problems over time and across multiple domains. Additionally, the potential importance of task-incongruent behavior is proposed for further study.

Gender Integration on U.S. Navy Submarines: Views of the First Wave

Science.gov (United States)

2015-06-01

Radiological Controls Assistant DACOWITS Defense Advisory Committee on Women in the Services DH Department Head DINQ delinquent DO Division...Previous studies have attempted to build statistical models based on surface fleet data to forecast female sustainability in the submarine fleet, yet 2...their integration? Such questions cannot be answered by collecting the type of quantitative data that can be analyzed using statistical methods. Complex

JUPITER’S PHASE VARIATIONS FROM CASSINI : A TESTBED FOR FUTURE DIRECT-IMAGING MISSIONS

International Nuclear Information System (INIS)

Mayorga, L. C.; Jackiewicz, J.; Rages, K.; West, R. A.; Knowles, B.; Lewis, N.; Marley, M. S.

2016-01-01

We present empirical phase curves of Jupiter from ∼0° to 140° as measured in multiple optical bandpasses by Cassini /Imaging Science Subsystem (ISS) during the Millennium flyby of Jupiter in late 2000 to early 2001. Phase curves are of interest for studying the energy balance of Jupiter and understanding the scattering behavior of the planet as an exoplanet analog. We find that Jupiter is significantly darker at partial phases than an idealized Lambertian planet by roughly 25% and is not well fit by Jupiter-like exoplanet atmospheric models across all wavelengths. We provide analytic fits to Jupiter’s phase function in several Cassini /ISS imaging filter bandpasses. In addition, these observations show that Jupiter’s color is more variable with phase angle than predicted by models. Therefore, the color of even a near Jupiter-twin planet observed at a partial phase cannot be assumed to be comparable to that of Jupiter at full phase. We discuss how the Wide-Field Infrared Survey Telescope and other future direct-imaging missions can enhance the study of cool giants.

Evaluation of Freshwater Aquatic Resources and Stormwater Management at U.S. Naval Submarine Base, Bangor, Washington

National Research Council Canada - National Science Library

May, Christopher

1997-01-01

Surface and storm water conditions on the Naval Submarine Base (NSB), Bangor, Washington, are evaluated, and recommendations are made to improve water quality and enhance the ecological integrity of aquatic resources located on the base...

Autonomous long-term gamma-spectrometric monitoring of submarine groundwater discharge trends in Hawaii

Czech Academy of Sciences Publication Activity Database

Dulai, H.; Kameník, Jan; Waters, C. A.; Kennedy, J.; Babinec, J.; Jolly, J.; Williamson, M.

2016-01-01

Roč. 307, č. 3 (2016), s. 1865-1870 ISSN 0236-5731. [10th International Conference on Methods and Applications of Radioanalytical Chemistry (MARC). Kailua Kona, 12.04.2015-17.04.2015] Institutional support: RVO:61389005 Keywords : submarine groundwater discharge * long-term SGD monitoring * underwater gammaspectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.282, year: 2016

PFERD Mission: Pluto Flyby Exploration/Research Design

Science.gov (United States)

Lemke, Gary; Zayed, Husni; Herring, Jason; Fuehne, Doug; Sutton, Kevin; Sharkey, Mike

1990-01-01

The Pluto Flyby Exploration/Research Design (PFERD) mission will consist of a flyby spacecraft to Pluto and its satellite, Charon. The mission lifetime is expected to be 18 years. The Titan 4 with a Centaur upper stage will be utilized to launch the craft into the transfer orbit. The proposal was divided into six main subsystems: (1) scientific instrumentation; (2) command, communications, and control: (3) altitude and articulation control; (4) power and propulsion; (5) structures and thermal control; and (6) mission management and costing. Tradeoff studies were performed to optimize all factors of design, including survivability, performance, cost, and weight. Problems encountered in the design are also presented.

Marine litter in submarine canyons of the Bay of Biscay

Science.gov (United States)

van den Beld, Inge M. J.; Guillaumont, Brigitte; Menot, Lénaïck; Bayle, Christophe; Arnaud-Haond, Sophie; Bourillet, Jean-François

2017-11-01

Marine litter is a matter of increasing concern worldwide, from shallow seas to the open ocean and from beaches to the deep-seafloor. Indeed, the deep sea may be the ultimate repository of a large proportion of litter in the ocean. We used footage acquired with a Remotely Operated Vehicle (ROV) and a towed camera to investigate the distribution and composition of litter in the submarine canyons of the Bay of Biscay. This bay contains many submarine canyons housing Vulnerable Marine Ecosystems (VMEs) such as scleractinian coral habitats. VMEs are considered to be important for fish and they increase the local biodiversity. The objectives of the study were to investigate and discuss: (i) litter density, (ii) the principal sources of litter, (iii) the influence of environmental factors on the distribution of litter, and (iv) the impact of litter on benthic communities. Litter was found in all 15 canyons and at three sites on the edge of the continental shelf/canyon, in 25 of 29 dives. The Belle-île and Arcachon Canyons contained the largest amounts of litter, up to 12.6 and 9.5 items per 100 images respectively. Plastic items were the most abundant (42%), followed by fishing-related items (16%). The litter had both a maritime and a terrestrial origin. The main sources could be linked to fishing activities, major shipping lanes and river discharges. Litter appeared to accumulate at water depths of 801-1100 m and 1401-1700 m. In the deeper of these two depth ranges, litter accumulated on a geologically structured area, accounting for its high frequency at this depth. A larger number of images taken in areas of coral in the shallower of these two depth ranges may account for the high frequency of litter detection at this depth. A larger number of litter items, including plastic objects in particular, were observed on geological structures and in coral areas than on areas of bare substratum. The distribution of fishing-related items was similar for the various types of

Volume transport data from a submarine cable in the Florida Strait from 2015 (NCEI Accession 0140278)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Daily mean and raw voltage volume transport data of the Florida Current collected with a submarine cable spanning from South Florida to the Grand Bahama Island in...

Volume transport data from a submarine cable in the Florida Strait from 2016 (NCEI Accession 0159429)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Daily mean and raw voltage volume transport data of the Florida Current collected with a submarine cable spanning from South Florida to the Grand Bahama Island in...

Volume transport data from a submarine cable in the Florida Strait in 2014 (NODC Accession 0125429)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Daily mean and raw voltage volume transport data of the Florida Current collected with a submarine cable spanning from South Florida to the Grand Bahama Island in...

Enhancing Team Performance for Long-Duration Space Missions

Science.gov (United States)

Orasanu, Judith M.

2009-01-01

Success of exploration missions will depend on skilled performance by a distributed team that includes both the astronauts in space and Mission Control personnel. Coordinated and collaborative teamwork will be required to cope with challenging complex problems in a hostile environment. While thorough preflight training and procedures will equip creW'S to address technical problems that can be anticipated, preparing them to solve novel problems is much more challenging. This presentation will review components of effective team performance, challenges to effective teamwork, and strategies for ensuring effective team performance. Teamwork skills essential for successful team performance include the behaviors involved in developing shared mental models, team situation awareness, collaborative decision making, adaptive coordination behaviors, effective team communication, and team cohesion. Challenges to teamwork include both chronic and acute stressors. Chronic stressors are associated with the isolated and confined environment and include monotony, noise, temperatures, weightlessness, poor sleep and circadian disruptions. Acute stressors include high workload, time pressure, imminent danger, and specific task-related stressors. Of particular concern are social and organizational stressors that can disrupt individual resilience and effective mission performance. Effective team performance can be developed by training teamwork skills, techniques for coping with team conflict, intracrew and intercrew communication, and working in a multicultural team; leadership and teamwork skills can be fostered through outdoor survival training exercises. The presentation will conclude with an evaluation of the special requirements associated with preparing crews to function autonomously in long-duration missions.

Composition and fluxes of submarine groundwater along the Caribbean coast of the Yucatan Peninsula

Science.gov (United States)

Null, Kimberly A.; Knee, Karen L.; Crook, Elizabeth D.; de Sieyes, Nicholas R.; Rebolledo-Vieyra, Mario; Hernández-Terrones, Laura; Paytan, Adina

2014-04-01

Submarine groundwater discharge (SGD) to the coastal environment along the eastern Yucatan Peninsula, Quintana Roo, Mexico was investigated using a combination of tracer mass balances and analytical solutions. Two distinct submarine groundwater sources including water from the unconfined surficial aquifer discharging at the beach face and water from a deeper aquifer discharging nearshore through submarine springs (ojos) were identified. The groundwater of nearshore ojos was saline and significantly enriched in short-lived radium isotopes (223Ra, 224Ra) relative to the unconfined aquifer beach face groundwater. We estimated SGD from ojos using 223Ra and used a salinity mass balance to estimate the freshwater discharge at the beach face. Analytical calculations were also used to estimate wave set-up and tidally driven saline seepage into the surf zone and were compared to the salinity-based freshwater discharge estimates. Results suggest that average SGD from ojos along the Yucatan Peninsula Caribbean coast is on the order of 308 m3 d-1 m-1 and varies between sampling regions. Higher discharge was observed in the southern regions (568 m3 d-1 m-1) compared to the north (48 m3 d-1 m-1). Discharge at the beach face was in the range of 3.3-8.5 m3 d-1 m-1 for freshwater and 2.7 m3 d-1 m-1 for saline water based on the salinity mass balance and wave- and tidally-driven discharge, respectively. Although discharge from the ojos was larger in volume than discharge from the unconfined aquifer at the beach face, dissolved inorganic nitrogen (DIN) was significantly higher in beach groundwater; thus, discharge of this unconfined beach aquifer groundwater contributed significantly to total DIN loading to the coast. DIN fluxes were up to 9.9 mol d-1 m-1 from ojos and 2.1 mol d-1 m-1 from beach discharge and varied regionally along the 500 km coastline sampled. These results demonstrate the importance of considering the beach zone as a significant nutrient source to coastal waters

Mapping submarine sand waves with multiband imaging radar - 2. Experimental results and model comparison

NARCIS (Netherlands)

Vogelzang, J.; Wensink, G.J.; Calkoen, C.J.; Kooij, M.W.A. van der

1997-01-01

On August 16, 1989, and on July 12, 1991, experiments were performed to study the mapping of submarine sand waves with the airborne imaging radar, a polarimetric (and, in 1991, interferometric) airborne P, L, and C band synthetic aperture radar system. The experiments took place in an area 30 km off

Canada and Missions for Peace

International Development Research Centre (IDRC) Digital Library (Canada)

The study focuses primarily on Canada's role in these missions in light of ..... simply because peacekeeping has been the chief form of UN intervention and one in which ... Other factors, such as financial constraints and increasing social problems ..... Luck, superior armaments, the shortage of professional officers among the ...

Effects of seasonal vitamin D deficiency and respiratory acidosis on bone metabolism markers in submarine crewmembers during prolonged patrols.

Science.gov (United States)

Holy, Xavier; Collombet, Jean-Marc; Labarthe, Frédéric; Granger-Veyron, Nicolas; Bégot, Laurent

2012-02-01

The aim of the study was to determine the seasonal influence of vitamin D status on bone metabolism in French submariners over a 2-mo patrol. Blood samples were collected as follows: prepatrol and patrol days 20, 41, and 58 on crewmembers from both a winter (WP; n = 20) and a summer patrol (SP; n = 20), respectively. Vitamin D status was evaluated for WP and SP. Moreover, extended parameters for acid-base balance (Pco(2), pH, and bicarbonate), bone metabolism (bone alkaline phosphatase and COOH-terminal telopeptide of type I collagen), and mineral homeostasis (parathyroid hormone, ionized calcium and phosphorus) were scrutinized. As expected, SP vitamin D status was higher than WP vitamin D status, regardless of the considered experimental time. A mild chronic respiratory acidosis (CRA) was identified in both SP and WP submariners, up to patrol day 41. Such an occurrence paired up with an altered bone remodeling coupling (decreased bone alkaline phosphatase-to-COOH-terminal telopeptide of type I collagen ratio). At the end of the patrol (day 58), a partial compensation of CRA episode, combined with a recovered normal bone remodeling coupling, was observed in SP, not, however, in WP submariners. The mild CRA episode displayed over the initial 41-day submersion period was mainly induced by a hypercapnia resulting from the submarine-enriched CO(2) level. The correlated impaired bone remodeling may imply a physiological attempt to compensate this acidosis via bone buffering. On patrol day 58, the discrepancy observed in terms of CRA compensation between SP and WP may result from the seasonal influence on vitamin D status.

Self-Directed Gambling Changes: Trajectory of Problem Gambling Severity in Absence of Treatment.

Science.gov (United States)

Kushnir, Vladyslav; Godinho, Alexandra; Hodgins, David C; Hendershot, Christian S; Cunningham, John A

2018-03-27

Most problem gamblers do not seek formal treatment, recovering on their own through cognitive re-appraisal or self-help strategies. Although barriers to treatment have been extensively studied, there is a paucity of research on self-directed changes in problem gambling and very few studies have examined these changes prospectively. The aim of this study was to examine the trajectory of gambling severity and behavior change over an 18-month period, among a sample of non-treatment seeking/attending problem gamblers recruited from the community (N = 204) interested in quitting or reducing gambling. Separate mixed effects models revealed that in absence of formal treatment, significant reductions in gambling severity, frequency, and amount gambled could be observed over the course of a 6 to 9-month period and that changes experienced within the first 12 months were maintained for an extended 6 months. Problem gambling severity at baseline was significantly associated with changes in severity over time, such that participants with more severe gambling problems demonstrated greater reductions in their gambling severity over time. A total of 11.1% of participants gambled within a low-risk threshold at 18 months, although 28.7% of the sample reported consecutive gambling severity scores below problem levels for the duration of 1 year or longer. The findings suggest that among problem gamblers motivated to quit or reduce their gambling, significant self-directed changes in gambling severity can occur over a relatively short time. Additional prospective studies are needed to document the role of specific self-help tools or thought processes in exacting gambling changes.

Modern solvers for Helmholtz problems

CERN Document Server

Tang, Jok; Vuik, Kees

2017-01-01

This edited volume offers a state of the art overview of fast and robust solvers for the Helmholtz equation. The book consists of three parts: new developments and analysis in Helmholtz solvers, practical methods and implementations of Helmholtz solvers, and industrial applications. The Helmholtz equation appears in a wide range of science and engineering disciplines in which wave propagation is modeled. Examples are: seismic inversion, ultrasone medical imaging, sonar detection of submarines, waves in harbours and many more. The partial differential equation looks simple but is hard to solve. In order to approximate the solution of the problem numerical methods are needed. First a discretization is done. Various methods can be used: (high order) Finite Difference Method, Finite Element Method, Discontinuous Galerkin Method and Boundary Element Method. The resulting linear system is large, where the size of the problem increases with increasing frequency. Due to higher frequencies the seismic images need to b...

3-D seismic characterization of submarine landslides on a Miocene carbonate platform (Luconia Province, Malaysia)

NARCIS (Netherlands)

Zampetti, V.; Schlager, W.; van Konijnenburg, J.H; Everts, A.J.

2004-01-01

3-D seismic reflection data and a variance cube are used to determine the architecture and investigate the triggering processes of submarine landslides affecting the flanks of a Miocene carbonate platform in the Luconia Province, Malaysia. The slide masses exhibit, in time-slice displays, chaotic,

Near-bottom particulate matter dynamics in the Nazare submarine canyon under calm and stormy conditions

NARCIS (Netherlands)

Martín, J.; Palanques, A.; Vitorino, J.; Oliveira, A.; de Stigter, H.C.

2011-01-01

Two mooring lines equipped with near-bottom sediment traps were deployed in the axis of the Nazare submarine canyon at similar to 1600 and similar to 3300 m depth, respectively. We studied time-series of particle flux, composition (biogenic silica, carbonates, organic matter and lithogenic

Russian Nuclear Submarines: U.S. Participation in the Arctic Military Environmental Cooperation Program Needs Better Justification

National Research Council Canada - National Science Library

2004-01-01

.... AMEC has primarily focused on Russia's aging fleet of nuclear submarines. Section 324 of the National Defense Authorization Act for Fiscal Year 2004 required GAO to review AMEC, including its relationship to the Department of Defense's (DoD...

Setting a personal career direction.

Science.gov (United States)

McCurdy, Fredrick A; Marcdante, Karen

2003-01-01

In summary, we believe that both you and your organization should have a set of core values, a well-defined mission (core purpose), and a vision of the future. Ideally, your projects and activities should be congruent with your mission and values, you should be pursuing your vision, and all of this should be congruent with the organization mission and values. Practically speaking, most individuals we have worked with over the years find themselves in two different groups at this point in the exercise. The minority find that their personal mission is not at all similar to the mission of their current organization and they find it necessary to seriously reevaluate their personal career direction. Sometimes, this results in them finding some other place to work. On the other hand, the majority discover their personal mission is in reasonable agreement with that of their organization. For both, this exercise has helped them clarify and better manage their personal career direction.

Psychological considerations of man in space: Problems & solutions

Science.gov (United States)

Kass, J.; Kass, R.; Samaltedinov, I.

With concrete plans for long duration flight taking form a new impetus is lent to preparing man for this hostile and unnatural environment. Cramped conditions, isolation from family and loved ones, work stress, fear, and incompatibility with fellow crew, are but a few of the problems suffered by astronauts and cosmonauts during their long missions in orbit about the earth. Although criteria for selection of crew is one aspect of attacking the problem, it has not solved it Notwithstanding good selection, team combination, and counselling before flight, problems have still occurred with unwanted consequences. Incompatibility of team members, far from being the exception, has been frequent. This has been detrímental both physiologically and psychologically for the individual as well as for the operational success and safety of the missions. Because problems will inevitably occur in future long duration missions, especially when they are of international and multi-cultural nature, the importance of dealing with them is underlined. This paper takes a different approach towards ameliorating these problems, namely that of psychological group training before a mission.

Investigation of Submarine Groundwater Discharge along the Tidal Reach of the Caloosahatchee River, Southwest Florida

Science.gov (United States)

Reich, Christopher D.

2010-01-01

The tidal reach of the Caloosahatchee River is an estuarine habitat that supports a diverse assemblage of biota including aquatic vegetation, shellfish, and finfish. The system has been highly modified by anthropogenic activity over the last 150 years (South Florida Water Management District (SFWMD), 2009). For example, the river was channelized and connected to Lake Okeechobee in 1881 (via canal C-43). Subsequently, three control structures (spillway and locks) were installed for flood protection (S-77 and S-78 in the 1930s) and for saltwater-intrusion prevention (S-79, W.P. Franklin Lock and Dam in 1966). The emplacement of these structures and their impact to natural water flow have been blamed for water-quality problems downstream within the estuary (Flaig and Capece, 1998; SFWMD, 2009). Doering and Chamberlain (1999) found that the operation of these control structures caused large and often rapid variations in salinity during various times of the year. Variable salinities could have deleterious impacts on the health of organisms in the Caloosahatchee River estuary. Flow restriction along the Caloosahatchee has also been linked to surface-water eutrophication problems (Doering and Chamberlain, 1999; SFWMD, 2009) and bottom-sediment contamination (Fernandez and others, 1999). Sources of nutrients (nitrogen and phosphorous) that cause eutrophication are primarily from residential sources and agriculture, though wastewater-treatment-plant discharges can also play a major role (SFWMD, 2009). The pathway for many of these nutrients is by land runoff and direct discharge from stormwater drains. An often overlooked source of nutrients and other chemical constituents is from submarine groundwater discharge (SGD). SGD can be either a diffuse or point source (for example, submarine springs) of nutrients and other chemical constituents to coastal waters (Valiela and others, 1990; Swarzenski and others, 2001; 2006; 2007; 2008). SGD can be composed of either fresh or

First Survey For Submarine Hydrothermal Vents In NE Sulawesi, Indonesia

Science.gov (United States)

McConachy, T.; Binns, R.; Permana, H.

2001-12-01

The IASSHA-2001 cruise (Indonesia-Australia Survey for Submarine Hydrothermal Activity) was successfully conducted from June 1 to June 29 on board Baruna Jaya VIII. Preliminary results are reported of the first expedition to locate and study submarine hydrothermal activity in north east Sulawesi. Leg A focussed on Tomini Bay, a virtually unexplored Neogene sedimentary basin. Its objective was to test whether modern sediment-hosted hydrothermal activity occurred on the sea floor. The results of new bathymetric mapping, sediment coring and CTD/transmissometer hydrocasts negate the likely presence in central Tomini Bay of large-scale modern analogues of hydrothermal massive sulfide environments involving hydrothermal venting of basinal or magma-derived fluids into reduced sediments. It is possible that the "heat engine" required to drive circulation of basinal and hydrothermal fluids is today too weak. Surveys around Colo volcano indicate that it may be in its final stage of evolution. Leg B studied the arc and behind-arc sectors of the Sangihe volcanic island chain extending northwards from Quaternary volcanoes on the northeastern tip of Sulawesi's North Arm, near Manado. West of the main active chain and extending northwards from Manado there is a subparallel ridge surmounted by a number of high (>2000 m) seamounts of uncertain age. Fifteen relatively high-standing submarine edifices were crossed during this leg, of which nine were tested for hydrothermal activity by hydrocast and dredging. Eight sites were known from previous bathymetric surveys, and seven are new discoveries made by narrow-beam or multibeam echo sounding. Two submarine edifices at least 1000 m high were discovered in the strait immediately north of Awu volcano on Sangihe Island. One, with crest at 206 m, is surrounded by a circular platform 300m deep which we infer to be a foundered fringing reef to a formerly emergent island. The other, lacking such a platform, appears relatively young and may be

Direct Measurements of the Evolution and Impact of Sediment Density Flows as they Pass Through Monterey Submarine Canyon, Offshore California

Science.gov (United States)

Paull, C. K.; Talling, P.; Maier, K. L.; Parsons, D. R.; Xu, J.; Caress, D. W.; Gwiazda, R.; Lundsten, E. M.; Anderson, K.; Barry, J.; Chaffey, M. R.; O'Reilly, T. C.; Rosenberger, K. J.; Gales, J. A.; McGann, M.; McCann, M. P.; Simmons, S.; Sumner, E.

2017-12-01

Sediment density flows flushing through submarine canyons carry globally significant amounts of material into the deep sea to form many of the largest sediment accumulations on Earth. Despite their global significance, these flows remain poorly understood because they have rarely been directly measured. Here we provide an initial overview of the recently completed Coordinated Canyon Experiment (CCE), which was undertaken specifically to provide detailed measurements of sediment density flows and their impact on seafloor morphology and sedimentology. No previous study has deployed as extensive an array of monitoring sensors along a turbidity current pathway. During the 18 months of the CCE, at least 15 sediment density flows were recorded within the axis of Monterey Canyon. Because no external triggers (i.e., earthquakes or floods) correlate with these flows, they must have originated as failures in the canyon floor or canyon flanks. Three flows ignited and ran out for > 50 km from water depths of 1,860 m, reaching velocities up to 8.1 m/s. The rest of the flows died out within the array. During these events, large objects on or in the canyon floor were displaced substantial distances downslope, including a 7.1 km downslope movement of an entire mooring; a 4.6 km displacement of an 860 kg instrument frame followed by repeated down canyon displacements of this same frame after it was entombed in sediment; and multiple depth changes of man-made boulders containing acceleration and pressure sensors. During this same time interval the canyon floor was mapped six times with autonomous underwater vehicles covering the canyon thalweg at the upper and lower end of the instrument array (200-540 and 1350-1880 m water depths). The repeated mapping surveys reveal that flows caused +3 to -3 m bathymetric changes within a continuous clearly defined 200 m wide swath running along the canyon axis in 540 m water depth. This study shows that sediment density flows caused massive

Geochemical stratigraphy of submarine lavas (3-5 Ma) from the Flamengos Valley, Santiago, Cape Verde

DEFF Research Database (Denmark)

Barker, Abigail K; Holm, Paul Martin; Peate, David W.

2009-01-01

New high-precision Pb-Sr-Nd isotope, major and trace element and mineral chemistry data are presented for the submarine stage of ocean island volcanism on Santiago, one of the southern islands of the Cape Verde archipelago. Pillow basalts and hyaloclastites in the Flamengos Valley are divided...

The near boiling reactor: Conceptual design of a small inherently safe nuclear reactor to extend the operational capability of the Victoria Class submarine

Science.gov (United States)

Cole, Christopher J. P.

Nuclear power has several unique advantages over other air independent energy sources for nuclear combat submarines. An inherently safe, small nuclear reactor, capable of supply the hotel load of the Victoria Class submarines, has been conceptually developed. The reactor is designed to complement the existing diesel electric power generation plant presently onboard the submarine. The reactor, rated at greater than 1 MW thermal, will supply electricity to the submarine's batteries through an organic Rankine cycle energy conversion plant at 200 kW. This load will increase the operational envelope of the submarine by providing up to 28 continuous days submerged, allowing for an enhanced indiscretion ratio (ratio of time spent on the surface versus time submerged) and a limited under ice capability. The power plant can be fitted into the existing submarine by inserting a 6 m hull plug. With its simplistic design and inherent safety features, the reactor plant will require a minimal addition to the crew. The reactor employs TRISO fuel particles for increased safety. The light water coolant remains at atmospheric pressure, exiting the core at 96°C. Burn-up control and limiting excess reactivity is achieved through movable reflector plates. Shut down and regulatory control is achieved through the thirteen hafnium control rods. Inherent safety is achieved through the negative prompt and delayed temperature coefficients, as well as the negative void coefficient. During a transient, the boiling of the moderator results in a sudden drop in reactivity, essentially shutting down the reactor. It is this characteristic after which the reactor has been named. The design of the reactor was achieved through modelling using computer codes such as MCNP5, WIMS-AECL, FEMLAB, and MicroShield5, in addition to specially written software for kinetics, heat transfer and fission product poisoning calculations. The work has covered a broad area of research and has highlighted additional areas

The near boiling reactor : conceptual design of a small inherently safe nuclear reactor to extend the operational capability of the Victoria Class submarine

International Nuclear Information System (INIS)

Cole, C.J.P.

2005-01-01

Nuclear power has several unique advantages over other air independent energy sources for nuclear combat submarines. An inherently safe, small nuclear reactor, capable of supply the hotel load of the 'Victoria' Class submarines, has been conceptually developed. The reactor is designed to complement the existing diesel electric power generation plant presently onboard the submarine. The reactor, rated at greater than 1 MW thermal, will supply electricity to the submarine's batteries through an organic Rankine cycle energy conversion plant at 200 kW. This load will increase the operational envelope of the submarine by providing up to 28 continuous days submerged, allowing for an enhanced indiscretion ratio (ratio of time spent on the surface versus time submerged) and a limited under ice capability. The power plant can be fitted into the existing submarine by inserting a 6 m hull plug. With its simplistic design and inherent safety features, the reactor plant will require a minimal addition to the crew. The reactor employs TRISO fuel particles for increased safety. The light water coolant remains at atmospheric pressure, exiting the core at 96 o C. Burn-up control and limiting excess reactivity is achieved through movable reflector plates. Shut down and regulatory control is achieved through the thirteen hafnium control rods. Inherent safety is achieved through the negative prompt and delayed temperature coefficients, as well as the negative void coefficient. During a transient, the boiling of the moderator results in a sudden drop in reactivity, essentially shutting down the reactor. It is this characteristic after which the reactor has been named. The design of the reactor was achieved through modelling using computer codes such as MCNP5, WIMS-AECL, FEMLAB, and MicroShield5, in addition to specially written software for kinetics, heat transfer and fission product poisoning calculations. The work has covered a broad area of research and has highlighted additional

Artificial intelligence and design: Opportunities, research problems and directions

Science.gov (United States)

Amarel, Saul

1990-01-01

The issues of industrial productivity and economic competitiveness are of major significance in the U.S. at present. By advancing the science of design, and by creating a broad computer-based methodology for automating the design of artifacts and of industrial processes, we can attain dramatic improvements in productivity. It is our thesis that developments in computer science, especially in Artificial Intelligence (AI) and in related areas of advanced computing, provide us with a unique opportunity to push beyond the present level of computer aided automation technology and to attain substantial advances in the understanding and mechanization of design processes. To attain these goals, we need to build on top of the present state of AI, and to accelerate research and development in areas that are especially relevant to design problems of realistic complexity. We propose an approach to the special challenges in this area, which combines 'core work' in AI with the development of systems for handling significant design tasks. We discuss the general nature of design problems, the scientific issues involved in studying them with the help of AI approaches, and the methodological/technical issues that one must face in developing AI systems for handling advanced design tasks. Looking at basic work in AI from the perspective of design automation, we identify a number of research problems that need special attention. These include finding solution methods for handling multiple interacting goals, formation problems, problem decompositions, and redesign problems; choosing representations for design problems with emphasis on the concept of a design record; and developing approaches for the acquisition and structuring of domain knowledge with emphasis on finding useful approximations to domain theories. Progress in handling these research problems will have major impact both on our understanding of design processes and their automation, and also on several fundamental questions

Surveillance mission planning for UAVs in GPS-denied urban environment

Science.gov (United States)

Pengfei, Wang

In this thesis, the issues involved in the mission planning of UAVs for city surveillance have been studied. In this thesis, the research includes two major parts. Firstly, a mission planning system is developed that generates mission plans for a group of fixed-wing UAVs with on-board gimballed cameras to provide continuous surveillance over an urban area. Secondly, the problem of perching location selection (as part of perch-and-stare surveillance mission) for rotary-wing UAVs in a GPS-denied environment is studied. In this kind of mission, a UAV is dispatched to perch on a roof of a building to keep surveillance on a given target. The proposed algorithms to UAV surveillance mission planning (fixed-wing and rotary-wing) have been implemented and tested. It represents an important step towards achieving autonomous planning in UAV surveillance missions.

Evolution of submarine eruptive activity during the 2011-2012 El Hierro event as documented by hydroacoustic images and remotely operated vehicle observations

Science.gov (United States)

Somoza, L.; González, F. J.; Barker, S. J.; Madureira, P.; Medialdea, T.; de Ignacio, C.; Lourenço, N.; León, R.; Vázquez, J. T.; Palomino, D.

2017-08-01

Submarine volcanic eruptions are frequent and important events, yet they are rarely observed. Here we relate bathymetric and hydroacoustic images from the 2011 to 2012 El Hierro eruption with surface observations and deposits imaged and sampled by ROV. As a result of the shallow submarine eruption, a new volcano named Tagoro grew from 375 to 89 m depth. The eruption consisted of two main phases of edifice construction intercalated with collapse events. Hydroacoustic images show that the eruptions ranged from explosive to effusive with variable plume types and resulting deposits, even over short time intervals. At the base of the edifice, ROV observations show large accumulations of lava balloons changing in size and type downslope, coinciding with the area where floating lava balloon fallout was observed. Peaks in eruption intensity during explosive phases generated vigorous bubbling at the surface, extensive ash, vesicular lapilli and formed high-density currents, which together with periods of edifice gravitational collapse, produced extensive deep volcaniclastic aprons. Secondary cones developed in the last stages and show evidence for effusive activity with lava ponds and lava flows that cover deposits of stacked lava balloons. Chaotic masses of heterometric boulders around the summit of the principal cone are related to progressive sealing of the vent with decreasing or variable magma supply. Hornitos represent the final eruptive activity with hydrothermal alteration and bacterial mats at the summit. Our study documents the distinct evolution of a submarine volcano and highlights the range of deposit types that may form and be rapidly destroyed in such eruptions.Plain Language SummaryToday and through most of geological history, the greatest number and volume of volcanic eruptions on Earth have occurred underwater. However, in comparison to subaerial eruption, little is known about submarine eruptive processes as they are dangerous to cruise it over

A new one-man submarine is tested as vehicle for solid rocket booster retrieval

Science.gov (United States)

2000-01-01

- The one-man submarine known as DeepWorker 2000 is tested in Atlantic waters near Cape Canaveral, Fla. Nearby are divers; inside the sub is the pilot, Anker Rasmussen. The sub is being tested on its ability to duplicate the sometimes hazardous job United Space Alliance (USA) divers perform to recover the expended boosters in the ocean after a launch. The boosters splash down in an impact area about 140 miles east of Jacksonville and after recovery are towed back to KSC for refurbishment by the specially rigged recovery ships. DeepWorker 2000 will be used in a demonstration during retrieval operations after the upcoming STS-101 launch. The submarine pilot will demonstrate capabilities to cut tangled parachute riser lines using a manipulator arm and attach a Diver Operator Plug to extract water and provide flotation for the booster. DeepWorker 2000 was built by Nuytco Research Ltd., North Vancouver, British Columbia. It is 8.25 feet long, 5.75 feet high, and weighs 3,800 pounds. USA is a prime contractor to NASA for the Space Shuttle program.

Experimental submarine with closed cycle diesel engine. Final report. Experimentaltauchboot mit Argon-Kreislaufdieselmotor. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Haas, J.

1990-08-01

The Experimental Submarine SEAHORSE-KD is a fully operational autonomous test platform for an air independent propulsion system based on a closed cycle diesel engine. The Argon-Diesel known as MOTARK was a contribution from MAN Technologie AG, Munich, which also included process technology and control. Within the Argon cycle the exhaust gas is cooled down, cleaned from CO{sub 2} in a rotary scrubber and fed into the engine again after addition of oxygen. On surface, the engine can be operated on ambient air. During closed cycle operation, no media are exchanged with the ambient. The process works independently from the depth. Bruker Meerestechnik GmbH had to define the complete vehicle, developed and integrated the subsystems such as the LOX-system, the chemical and condensate plant, the fuel system, the propulsion and the electric system, etc. and carried out extensive workshop tests, shallow water and sea trials. The reliable functioning of the CCD-plant and of the complete Experimental Submarine could be convincingly demonstrated. A certificate has been issued by the Germanischer Lloyd. (orig.) With 90 refs., 15 figs.

Assessment of diagnostic technology in health care: rationale, methods, problems, and directions

National Research Council Canada - National Science Library

Sox, Harold C

1989-01-01

... Rationale, Methods, Problems, and Directions Harold Sox, Susan Stern, Douglas Owens, and Herbert L. Abrams Institute of Medicine NATIONAL ACADEMY PRESS WASHINGTON, D.C. 1989 Copyrightthe cannot be not from book, paper however, version for formatting, original authoritative the typesetting-specific the as from created publication files XML from...

ESASky: a new Astronomy Multi-Mission Interface

Science.gov (United States)

Baines, D.; Merin, B.; Salgado, J.; Giordano, F.; Sarmiento, M.; Lopez Marti, B.; Racero, E.; Gutierrez, R.; De Teodoro, P.; Nieto, S.

2016-06-01

ESA is working on a science-driven discovery portal for all its astronomy missions at ESAC called ESASky. The first public release of this service will be shown, featuring interfaces for sky exploration and for single and multiple targets. It requires no operational knowledge of any of the missions involved. A first public beta release took place in October 2015 and gives users world-wide simplified access to high-level science-ready data products from ESA Astronomy missions plus a number of ESA-produced source catalogues. XMM-Newton data, metadata and products were some of the first to be accessible through ESASky. In the next decade, ESASky aims to include not only ESA missions but also access to data from other space and ground-based astronomy missions and observatories. From a technical point of view, ESASky is a web application that offers all-sky projections of full mission datasets using a new-generation HEALPix projection called HiPS; detailed geometrical footprints to connect all-sky mosaics to individual observations; direct access to the underlying mission-specific science archives and catalogues. The poster will be accompanied by a demo booth at the conference.

Gas mission; Mission gaz

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This preliminary report analyses the desirable evolutions of gas transport tariffing and examines some questions relative to the opening of competition on the French gas market. The report is made of two documents: a synthesis of the previous report with some recommendations about the tariffing of gas transport, about the modalities of network access to third parties, and about the dissociation between transport and trade book-keeping activities. The second document is the progress report about the opening of the French gas market. The first part presents the European problem of competition in the gas supply and its consequences on the opening and operation of the French gas market. The second part presents some partial syntheses about each topic of the mission letter of the Ministry of Economics, Finances and Industry: future evolution of network access tariffs, critical analysis of contractual documents for gas transport and delivery, examination of auxiliary services linked with the access to the network (modulation, balancing, conversion), consideration about the processing of network congestions and denied accesses, analysis of the metering dissociation between the integrated activities of gas operators. Some documents are attached in appendixes: the mission letter from July 9, 2001, the detailed analysis of the new temporary tariffs of GdF and CFM, the offer of methane terminals access to third parties, the compatibility of a nodal tariffing with the presence of three transport operators (GdF, CFM and GSO), the contract-type for GdF supply, and the contract-type for GdF connection. (J.S.)

Bacterial Diversity in Submarine Groundwater along the Coasts of the Yellow Sea

OpenAIRE

Ye, Qi; Liu, Jianan; Du, Jinzhou; Zhang, Jing

2016-01-01

Submarine groundwater (SGD) is one of the most significant pathways for the exchange of groundwater and/or source of nutrients, metals and carbon to the ocean, subsequently cause deleterious impacts on the coastal ecosystems. Microorganisms have been recognized as the important participators in the biogeochemical processes in the SGD. In this study, by utilizing 16S rRNA-based Illumina Miseq sequencing technology, we investigated bacterial diversity and distribution in both fresh well water a...

Robust approximate optimal guidance strategies for aeroassisted orbital transfer missions

Science.gov (United States)

Ilgen, Marc R.

This thesis presents the application of game theoretic and regular perturbation methods to the problem of determining robust approximate optimal guidance laws for aeroassisted orbital transfer missions with atmospheric density and navigated state uncertainties. The optimal guidance problem is reformulated as a differential game problem with the guidance law designer and Nature as opposing players. The resulting equations comprise the necessary conditions for the optimal closed loop guidance strategy in the presence of worst case parameter variations. While these equations are nonlinear and cannot be solved analytically, the presence of a small parameter in the equations of motion allows the method of regular perturbations to be used to solve the equations approximately. This thesis is divided into five parts. The first part introduces the class of problems to be considered and presents results of previous research. The second part then presents explicit semianalytical guidance law techniques for the aerodynamically dominated region of flight. These guidance techniques are applied to unconstrained and control constrained aeroassisted plane change missions and Mars aerocapture missions, all subject to significant atmospheric density variations. The third part presents a guidance technique for aeroassisted orbital transfer problems in the gravitationally dominated region of flight. Regular perturbations are used to design an implicit guidance technique similar to the second variation technique but that removes the need for numerically computing an optimal trajectory prior to flight. This methodology is then applied to a set of aeroassisted inclination change missions. In the fourth part, the explicit regular perturbation solution technique is extended to include the class of guidance laws with partial state information. This methodology is then applied to an aeroassisted plane change mission using inertial measurements and subject to uncertainties in the initial value

One Improvement Method of Reducing Duration Directly to Solve Time-Cost Tradeoff Problem

Science.gov (United States)

Jian-xun, Qi; Dedong, Sun

Time and cost are two of the most important factors for project plan and schedule management, and specially, time-cost tradeoff problem is one classical problem in project scheduling, which is also a difficult problem. Methods of solving the problem mainly contain method of network flow and method of mending the minimal cost. Thereinto, for the method of mending the minimal cost is intuitionistic, convenient and lesser computation, these advantages make the method being used widely in practice. But disadvantage of the method is that the result of each step is optimal but the terminal result maybe not optimal. In this paper, firstly, method of confirming the maximal effective quantity of reducing duration is designed; secondly, on the basis of above method and the method of mending the minimal cost, the main method of reducing duration directly is designed to solve time-cost tradeoff problem, and by analyzing validity of the method, the method could obtain more optimal result for the problem.

Monitoring El Hierro submarine volcanic eruption events with a submarine seismic array

Science.gov (United States)

Jurado, Maria Jose; Molino, Erik; Lopez, Carmen

2013-04-01

A submarine volcanic eruption took place near the southernmost emerged land of the El Hierro Island (Canary Islands, Spain), from October 2011 to February 2012. The Instituto Geografico Nacional (IGN) seismic stations network evidenced seismic unrest since July 2012 and was a reference also to follow the evolution of the seismic activity associated with the volcanic eruption. From the beginning of the eruption a geophone string was installed less than 2 km away from the new volcano, next to La Restinga village shore, to record seismic activity related to the volcanic activity, continuously and with special interest on high frequency events. The seismic array was endowed with 8, high frequency, 3 component, 250 Hz, geophone cable string with a separation of 6 m between them. The analysis of the dataset using spectral techniques allows the characterization of the different phases of the eruption and the study of its dynamics. The correlation of the data analysis results with the observed sea surface activity (ash and lava emission and degassing) and also with the seismic activity recorded by the IGN field seismic monitoring system, allows the identification of different stages suggesting the existence of different signal sources during the volcanic eruption and also the posteruptive record of the degassing activity. The study shows that the high frequency capability of the geophone array allow the study of important features that cannot be registered by the standard seismic stations. The accumulative spectral amplitude show features related to eruptive changes.

Practical methods for near-term piloted Mars missions

Science.gov (United States)

Zubrin, Robert M.; Weaver, David B.

1993-01-01

An evaluation is made of ways of using near-term technologies for direct and semidirect manned Mars missions. A notable feature of the present schemes is the in situ propellant production of CH4/O2 and H2O on the Martian surface in order to reduce surface consumable and return propellant requirements. Medium-energy conjunction class trajectories are shown to be optimal for such missions. Attention is given to the backup plans and abort philosophy of these missions. Either the Russian Energia B or U.S. Saturn VII launch vehicles may be used.

Mission Specialist Scott Parazynski arrives at KSC

Science.gov (United States)

1998-01-01

STS-95 Mission Specialist Scott E. Parazynski notes the time on his watch upon his late arrival aboard a T-38 jet at the Shuttle Landing Facility. Parazynski's first plane experienced problems at the stop at Tyndall AFB and he had to wait for another jet and pilot to finish the flight to KSC. He joined other crewmembers Mission Commander Curtis L. Brown Jr., Pilot Steven W. Lindsey, Mission Specialist Stephen K. Robinson, Payload Specialist John H. Glenn Jr., senator from Ohio, Mission Specialist Pedro Duque, with the European Space Agency (ESA), and Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA), for final pre-launch preparations. STS-95 is expected to launch at 2 p.m. EST on Oct. 29, last 8 days, 21 hours and 49 minutes, and land at 11:49 a.m. EST on Nov. 7.

Precursory diffuse CO2 and H2S emission signatures of the 2011-2012 El Hierro submarine eruption, Canary Islands

Science.gov (United States)

Pérez, Nemesio M.; Padilla, Germán D.; Padrón, Eleazar; Hernández, Pedro A.; Melián, Gladys V.; Barrancos, José; Dionis, Samara; Nolasco, Dácil; Rodríguez, Fátima; Calvo, David; Hernández, Íñigo

2012-08-01

On October 12, 2011, a submarine eruption began 2 km off the coast of La Restinga, south of El Hierro Island. CO2 and H2S soil efflux were continuously measured during the period of volcanic unrest by using the accumulation chamber method at two different geochemical stations, HIE01 and HIE07. Recorded CO2 and H2S effluxes showed precursory signals that preceded the submarine eruption. Beginning in late August, the CO2 efflux time series started increasing at a relatively constant rate over one month, reaching a maximum of 19 gm-2d-1 one week before the onset of the submarine volcanic eruption. The H2S efflux time series at HIE07 showed a pulse in H2S emission just one day before the initiation of the submarine eruption, reaching peak values of 42 mg m-2 d-1, 10 times the average H2S efflux recorded during the observation period. Since CO2 and H2S effluxes are strongly influenced by external factors, we applied a multiple regression analysis to remove their contribution. A statistical analysis showed that the long-term trend of the filtered data is well correlated with the seismic energy. We find that these geochemical stations are important monitoring sites for evaluating the volcanic activity of El Hierro and that they demonstrate the potential of applying continuous monitoring of soil CO2 and H2S efflux to improve and optimize the detection of early warning signals of future volcanic unrest episodes at El Hierro. Continuous diffuse degassing studies would likely prove useful for monitoring other volcanoes during unrest episodes.

STS-61 mission director's post-mission report

Science.gov (United States)

Newman, Ronald L.

1995-01-01

To ensure the success of the complex Hubble Space Telescope servicing mission, STS-61, NASA established a number of independent review groups to assess management, design, planning, and preparation for the mission. One of the resulting recommendations for mission success was that an overall Mission Director be appointed to coordinate management activities of the Space Shuttle and Hubble programs and to consolidate results of the team reviews and expedite responses to recommendations. This report presents pre-mission events important to the experience base of mission management, with related Mission Director's recommendations following the event(s) to which they apply. All Mission Director's recommendations are presented collectively in an appendix. Other appendixes contain recommendations from the various review groups, including Payload Officers, the JSC Extravehicular Activity (EVA) Section, JSC EVA Management Office, JSC Crew and Thermal Systems Division, and the STS-61 crew itself. This report also lists mission events in chronological order and includes as an appendix a post-mission summary by the lead Payload Deployment and Retrieval System Officer. Recommendations range from those pertaining to specific component use or operating techniques to those for improved management, review, planning, and safety procedures.

Haimormus shimojiensis, a new genus and species of Pseudozeuxidae (Crustacea: Tanaidacea from a submarine limestone cave in Northwestern Pacific

Directory of Open Access Journals (Sweden)

Keiichi Kakui

2018-04-01

Full Text Available We establish a new pseudozeuxid genus Haimormus gen. nov. based on a new species Haimormus shimojiensis sp. nov. which was collected from a submarine limestone cave with the entrance at 35 m depth, in the Northwestern Pacific Ocean. H. shimojiensis differs from the other confamilial members, Pseudozeuxo belizensis Sieg, 1982 and Charbeitanais spongicola Bamber & Bird, 1997, in having the pleonite 1 without the pleopod, the pereopods 2 and 3 propodus with a ventral spiniform seta, and the pereopods 4–6 propodus with one long and two short dorsodistal setae. A key to females of species of Pseudozeuxidae is presented. This is the first tanaidacean report from submarine caves around Japan.

Steady State Modelling of Three-core Wire Armoured Submarine Cables

DEFF Research Database (Denmark)

Baù, Matteo; Viafora, Nicola; Hansen, Chris Skovgaard

2016-01-01

This paper introduces Finite Element Method mod-elling techniques applied to wire armoured submarine three-core cables, whose nominal voltages range from 36 to 245 kV. The analysis is focused on the implementation of the net voltage cancellation principle in a 2D environment. The model is utilised...... confirm that the wire armour stranding is not accounted for, but also suggest that the ampacity underrating might be due to other inaccuracies in the IEC modelling indications. Overall, the difference in terms of current rating between the FEM and the IEC approach is found to be voltage dependent and more...

Launch Opportunities for Jupiter Missions Using the Gravity Assist

Directory of Open Access Journals (Sweden)

Young-Joo Song

2004-06-01

Full Text Available Interplanetary trajectories using the gravity assists are studied for future Korean interplanetary missions. Verifications of the developed softwares and results were performed by comparing data from ESA's Mars Express mission and previous results. Among the Jupiter exploration mission scenarios, multi-planet gravity assist mission to Jupiter (Earth-Mars-Earth-Jupiter Gravity Assist, EMEJGA trajectory requires minimum launch energy (C3 of 29.231 km2/s2 with 4.6 years flight times. Others, such as direct mission and single-planet(Mars gravity assist mission, requires launch energy (C3 of 75.656 km^2/s^2 with 2.98 years flight times and 63.590 km2/s2 with 2.33 years flight times, respectively. These results show that the planetary gravity assists can reduce launch energy, while EMEJGA trajectory requires the longer flight time than the other missions.

Voice loops as coordination aids in space shuttle mission control.

Science.gov (United States)

Patterson, E S; Watts-Perotti, J; Woods, D D

1999-01-01

Voice loops, an auditory groupware technology, are essential coordination support tools for experienced practitioners in domains such as air traffic management, aircraft carrier operations and space shuttle mission control. They support synchronous communication on multiple channels among groups of people who are spatially distributed. In this paper, we suggest reasons for why the voice loop system is a successful medium for supporting coordination in space shuttle mission control based on over 130 hours of direct observation. Voice loops allow practitioners to listen in on relevant communications without disrupting their own activities or the activities of others. In addition, the voice loop system is structured around the mission control organization, and therefore directly supports the demands of the domain. By understanding how voice loops meet the particular demands of the mission control environment, insight can be gained for the design of groupware tools to support cooperative activity in other event-driven domains.

Assessing submarine groundwater discharge (SGD) and nitrate fluxes in highly heterogeneous coastal karst aquifers: Challenges and solutions

Science.gov (United States)

Montiel, Daniel; Dimova, Natasha; Andreo, Bartolomé; Prieto, Jorge; García-Orellana, Jordi; Rodellas, Valentí

2018-02-01

Groundwater discharge in coastal karst aquifers worldwide represents a substantial part of the water budget and is a main pathway for nutrient transport to the sea. Groundwater discharge to the sea manifests under different forms, making its assessment very challenging particularly in highly heterogeneous coastal systems karst systems. In this study, we present a methodology approach to identify and quantify four forms of groundwater discharge in a mixed lithology system in southern Spain (Maro-Cerro Gordo) that includes an ecologically protected coastal area comprised of karstic marble. We found that groundwater discharge to the sea occurs via: (1) groundwater-fed creeks, (2) coastal springs, (3) diffuse groundwater seepage through seabed sediments, and (4) submarine springs. We used a multi-method approach combining tracer techniques (salinity, 224Ra, and 222Rn) and direct measurements (seepage meters and flowmeters) to evaluate the discharge. Groundwater discharge via submarine springs was the most difficult to assess due to their depth (up to 15 m) and extensive development of the springs conduits. We determined that the total groundwater discharge over the 16 km of shoreline of the study area was at least 11 ± 3 × 103 m3 d-1 for the four types of discharge assessed. Groundwater-derived nitrate (NO3-) fluxes to coastal waters over ∼3 km (or 20%) in a highly populated and farmed section of Maro-Cerro Gordo was 641 ± 166 mol d-1, or ∼75% of the total NO3- loading in the study area. We demonstrate in this study that a multi-method approach must be applied to assess all forms of SGD and derived nutrient fluxes to the sea in highly heterogeneous karst aquifer systems.

KEPLER Mission: development and overview

International Nuclear Information System (INIS)

Borucki, William J

2016-01-01

The Kepler Mission is a space observatory launched in 2009 by NASA to monitor 170 000 stars over a period of four years to determine the frequency of Earth-size and larger planets in and near the habitable zone of Sun-like stars, the size and orbital distributions of these planets, and the types of stars they orbit. Kepler is the tenth in the series of NASA Discovery Program missions that are competitively-selected, PI-directed, medium-cost missions. The Mission concept and various instrument prototypes were developed at the Ames Research Center over a period of 18 years starting in 1983. The development of techniques to do the 10 ppm photometry required for Mission success took years of experimentation, several workshops, and the exploration of many ‘blind alleys’ before the construction of the flight instrument. Beginning in 1992 at the start of the NASA Discovery Program, the Kepler Mission concept was proposed five times before its acceptance for mission development in 2001. During that period, the concept evolved from a photometer in an L2 orbit that monitored 6000 stars in a 50 sq deg field-of-view (FOV) to one that was in a heliocentric orbit that simultaneously monitored 170 000 stars with a 105 sq deg FOV. Analysis of the data to date has detected over 4600 planetary candidates which include several hundred Earth-size planetary candidates, over a thousand confirmed planets, and Earth-size planets in the habitable zone (HZ). These discoveries provide the information required for estimates of the frequency of planets in our galaxy. The Mission results show that most stars have planets, many of these planets are similar in size to the Earth, and that systems with several planets are common. Although planets in the HZ are common, many are substantially larger than Earth. (review article)

Management of information for mission operations using automated keyword referencing

Science.gov (United States)

Davidson, Roger A.; Curran, Patrick S.

1993-01-01

Although millions of dollars have helped to improve the operability and technology of ground data systems for mission operations, almost all mission documentation remains bound in printed volumes. This form of documentation is difficult and timeconsuming to use, may be out-of-date, and is usually not cross-referenced with other related volumes of mission documentation. A more effective, automated method of mission information access is needed. A new method of information management for mission operations using automated keyword referencing is proposed. We expound on the justification for and the objectives of this concept. The results of a prototype tool for mission information access that uses a hypertextlike user interface and existing mission documentation are shared. Finally, the future directions and benefits of our proposed work are described.

Steady and Unsteady Force and Moment Data on a DARPA2 Submarine

OpenAIRE

Whitfield, Cindy Carol

1999-01-01

Steady and unsteady force and moment experiments were conducted in the Virginia Tech Stability wind tunnel using the Dynamic Plunge-Pitch-Roll (DyPPiR) model mount to perform rapid time-dependent,high-excursion maneuvers. The experiments were performed for a DARPA2 submarine model using three widely spaced 2-force-component loadcells and three tri-axial accelerometers to extract the aerodynamic loads. The DARPA2 model was tested with different body configurations in two different test sect...

Cloud Computing Techniques for Space Mission Design

Science.gov (United States)

Arrieta, Juan; Senent, Juan

2014-01-01

The overarching objective of space mission design is to tackle complex problems producing better results, and faster. In developing the methods and tools to fulfill this objective, the user interacts with the different layers of a computing system.

Parts Quality Management: Direct Part Marking via Data Matrix Symbols for Mission Assurance

Science.gov (United States)

Moss, Chantrice

2013-01-01

A United States Government Accountability Office (GAO) review of twelve NASA programs found widespread parts quality problems contributing to significant cost overruns, schedule delays, and reduced system reliability. Direct part-marking with Data Matrix symbols could significantly improve the quality of inventory control and parts lifecycle management. This paper examines the feasibility of using 15 marking technologies for use in future NASA programs. A structural analysis is based on marked material type, operational environment (e.g., ground, suborbital, orbital), durability of marks, ease of operation, reliability, and affordability. A cost-benefits analysis considers marking technology (data plates, label printing, direct part marking) and marking types (two-dimensional machine-readable, human-readable). Previous NASA parts marking efforts and historical cost data are accounted for, including in-house vs. outsourced marking. Some marking methods are still under development. While this paper focuses on NASA programs, results may be applicable to a variety of industrial environments.

Isotopic evidence for the influence of typhoons and submarine canyons on the sourcing and transport behavior of biospheric organic carbon to the deep sea

Science.gov (United States)

Zheng, Li-Wei; Ding, Xiaodong; Liu, James T.; Li, Dawei; Lee, Tsung-Yu; Zheng, Xufeng; Zheng, Zhenzhen; Xu, Min Nina; Dai, Minhan; Kao, Shuh-Ji

2017-05-01

Export of biospheric organic carbon from land masses to the ocean plays an important role in regulating the global carbon cycle. High-relief islands in the western Pacific are hotspots for such land-to-ocean carbon transport due to frequent floods and active tectonics. Submarine canyon systems serve as a major conduit to convey terrestrial organics into the deep sea, particularly during episodic floods, though the nature of ephemeral sediment transportation through such canyons remains unclear. In this study, we deployed a sediment trap in southwestern Taiwan's Gaoping submarine canyon during summer 2008, during which Typhoon Kalmaegi impacted the study area. We investigated sources of particulate organic carbon and quantified the content of fossil organic carbon (OCf) and biospheric non-fossil carbon (OCnf) during typhoon and non-typhoon periods, based on relations between total organic carbon (TOC), isotopic composition (δ13 C, 14C), and nitrogen to carbon ratios (N/C) of newly and previously reported source materials. During typhoons, flooding connected terrestrial rivers to the submarine canyon. Fresh plant debris was not found in the trap except in the hyperpycnal layer, suggesting that only hyperpycnal flow is capable of entraining plant debris, while segregation had occurred during non-hyperpycnal periods. The OCnf components in typhoon flood and trapped samples were likely sourced from aged organics buried in ancient landslides. During non-typhoon periods, the canyon is more connected to the shelf, where waves and tides cause reworking, thus allowing abiotic and biotic processes to generate isotopically uniform and similarly aged OCnf for transport into the canyon. Therefore, extreme events coupled with the submarine canyon system created an efficient method for deep-sea burial of freshly produced organic-rich material. Our results shed light on the ephemeral transport of organics within a submarine canyon system on an active tectonic margin.

Direct Imaging of Stellar Surfaces: Results from the Stellar Imager (SI) Vision Mission Study

Science.gov (United States)

Carpenter, Kenneth; Schrijver, Carolus; Karovska, Margarita

2006-01-01

The Stellar Imager (SI) is a UV-Optical, Space-Based Interferometer designed to enable 0.1 milli-arcsecond (mas) spectral imaging of stellar surfaces and stellar interiors (via asteroseismology) and of the Universe in general. SI is identified as a "Flagship and Landmark Discovery Mission'' in the 2005 Sun Solar System Connection (SSSC) Roadmap and as a candidate for a "Pathways to Life Observatory'' in the Exploration of the Universe Division (EUD) Roadmap (May, 2005). The ultra-sharp images of the Stellar Imager will revolutionize our view of many dynamic astrophysical processes: The 0.1 mas resolution of this deep-space telescope will transform point sources into extended sources, and snapshots into evolving views. SI's science focuses on the role of magnetism in the Universe, particularly on magnetic activity on the surfaces of stars like the Sun. SI's prime goal is to enable long-term forecasting of solar activity and the space weather that it drives in support of the Living With a Star program in the Exploration Era. SI will also revolutionize our understanding of the formation of planetary systems, of the habitability and climatology of distant planets, and of many magneto-hydrodynamically controlled processes in the Universe. In this paper we will discuss the results of the SI Vision Mission Study, elaborating on the science goals of the SI Mission and a mission architecture that could meet those goals.

Gender and Direction of Effect of Alcohol Problems and Internalizing Symptoms in a Longitudinal Sample of College Students.

Science.gov (United States)

Homman, Lina E; Edwards, Alexis C; Cho, Seung Bin; Dick, Danielle M; Kendler, Kenneth S

2017-03-21

Alcohol problems and internalizing symptoms are consistently found to be associated but how they relate to each other is unclear. The present study aimed to address limitations in the literature of comorbidity of alcohol problems and internalizing symptoms by investigating the direction of effect between the phenotypes and possible gender differences in college students. We utilized data from a large longitudinal study of college students from the United States (N = 2607). Three waves of questionnaire-based data were collected over the first two years of college (in 2011-2013). Cross-lagged models were applied to examine the possible direction of effect of internalizing symptoms and alcohol problems. Possible effects of gender were investigated using multigroup modeling. There were significant correlations between alcohol problems and internalizing symptoms. A direction of effect was found between alcohol problems and internalizing symptoms but differed between genders. A unidirectional relationship varying with age was identified for males where alcohol problems initially predicted internalizing symptoms followed by internalizing symptoms predicting alcohol problems. For females, a unidirectional relationship existed wherein alcohol problems predicted internalizing symptoms. Conclusions/Importance: We conclude that the relationship between alcohol problems and internalizing symptoms is complex and differ between genders. In males, both phenotypes are predictive of each other, while in females the relationship is driven by alcohol problems. Importantly, our study examines a population-based sample, revealing that the observed relationships between alcohol problems and internalizing symptoms are not limited to individuals with clinically diagnosed mental health or substance use problems.

The Mission of the Registrar: A Ten-Year Retrospective

Science.gov (United States)

Lanier, David C.

2006-01-01

Records management, database management, and business process management--what do they have to do with the mission of the registrar? This article takes a look at how well the 1995 article, "The Mission of the Registrar Today," did in predicting the direction of the registrar's profession and makes some new predictions about future responsibilities…

A new algorithm for solving the inventory routing problem with direct shipment

Directory of Open Access Journals (Sweden)

Ali Hossein Mirzaei

2012-02-01

Full Text Available   In this paper a multi-commodity multi-period inventory routing problem in a two-echelon supply chain consisting of a manufacturer and a set of retailers has been studied. In addition to inventory management and distribution planning, production planning has also been considered in the above problem. The objective is to minimize total system cost that consists of production setup, inventory holding and distribution costs. The commodities are delivered to the retailers by an identical fleet of limited capacity vehicles through direct shipment strategy. Also it is assumed that production and storage capacity is limited and stockout is not allowed. Since similar problems without distribution planning are known as NP-hard, this is also an NP-hard problem. Therefore, in this paper, a new improved particle swarm optimization algorithm has been developed consisting of two distinguished phases for problem solving. First, the values of binary variables are determined using the proposed algorithm and then, the continuous variables are calculated by solving a linear programming model. Performance of the proposed algorithm has been compared with genetic and original particle swarm optimization algorithms using various samples of random problems. The findings imply significant performance of the proposed algorithm.         

Rethinking the globalisation of problem-based learning: how culture challenges self-directed learning.

NARCIS (Netherlands)

Frambach, J.M.; Driessen, E.W.; Chan, L.C.; Vleuten, C.P.M. van der

2012-01-01

Medical Education 2012: 46: 738-747 Context Medical schools worldwide are increasingly switching to student-centred methods such as problem-based learning (PBL) to foster lifelong self-directed learning (SDL). The cross-cultural applicability of these methods has been questioned because of their

The Gaia mission

OpenAIRE

Prusti, T.; de Bruijne, J. H. J.; Brown, A. G. A.; Vallenari, A.; Babusiaux, C.; Bailer-Jones, C. A. L.; Bastian, U.; Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.

2016-01-01

Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia wa...

Marital hostility and child sleep problems: direct and indirect associations via hostile parenting.

Science.gov (United States)

Rhoades, Kimberly A; Leve, Leslie D; Harold, Gordon T; Mannering, Anne M; Neiderhiser, Jenae M; Shaw, Daniel S; Natsuaki, Misaki N; Reiss, David

2012-08-01

The current study examined two family process predictors of parent-reported child sleep problems at 4.5 years in an adoption sample: marital hostility and hostile parenting. Participants were 361 linked triads of birth parents, adoptive parents, and adopted children. We examined direct and indirect pathways from marital hostility to child sleep problems via hostile parenting. Mothers' marital hostility at 9 months was associated with child sleep problems at 4.5 years. Fathers' marital hostility at 9 months evidenced an indirect effect on child sleep problems at 4.5 years via fathers' hostile parenting at 27 months. Findings were significant even after controlling for genetic influences on child sleep (i.e., birth parent internalizing disorders). The findings suggest targets for prevention and intervention programs that are potentially modifiable (e.g., hostile parenting, marital hostility), and inform theory by demonstrating that relations among marital hostility, hostile parenting, and child sleep problems are significant after accounting for genetic influences. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Asteroid retrieval missions enabled by invariant manifold dynamics

Science.gov (United States)

Sánchez, Joan Pau; García Yárnoz, Daniel

2016-10-01

Near Earth Asteroids are attractive targets for new space missions; firstly, because of their scientific importance, but also because of their impact threat and prospective resources. The asteroid retrieval mission concept has thus arisen as a synergistic approach to tackle these three facets of interest in one single mission. This paper reviews the methodology used by the authors (2013) in a previous search for objects that could be transported from accessible heliocentric orbits into the Earth's neighbourhood at affordable costs (or Easily Retrievable Objects, a.k.a. EROs). This methodology consisted of a heuristic pruning and an impulsive manoeuvre trajectory optimisation. Low thrust propulsion on the other hand clearly enables the transportation of much larger objects due to its higher specific impulse. Hence, in this paper, low thrust retrieval transfers are sought using impulsive trajectories as first guesses to solve the optimal control problem. GPOPS-II is used to transcribe the continuous-time optimal control problem to a nonlinear programming problem (NLP). The latter is solved by IPOPT, an open source software package for large-scale NLPs. Finally, a natural continuation procedure that increases the asteroid mass allows to find out the largest objects that could be retrieved from a given asteroid orbit. If this retrievable mass is larger than the actual mass of the asteroid, the asteroid retrieval mission for this particular object is said to be feasible. The paper concludes with an updated list of 17 EROs, as of April 2016, with their maximum retrievable masses by means of low thrust propulsion. This ranges from 2000 tons for the easiest object to be retrieved to 300 tons for the least accessible of them.

Marine environmental radioactivity surveys at nuclear submarine berths in the UK, 1989

International Nuclear Information System (INIS)

Fuller, D.; Casey, E.

1990-12-01

This report presents the results of the marine environmental radioactivity monitoring surveys of intertidal and underwater areas around nuclear submarine berths in the UK, including the US Naval Base at Holy Loch, which were carried out by Defence Radiological Protection Service (DRPS) during 1989. Also included are results of smaller scale intertidal surveys carried out by local staff but co-ordinated by DRPS, and as an Appendix a report by the US Navy detailing the results of their environmental radioactivity monitoring programme at Holy Loch. Cobalt-60, the nuclide of major importance in naval discharges, was detected in a number of samples but in most cases was attributable to discharges by other operators. Concentrations in any case were found to be low, and at no survey location did the calculated annual radiation dose commitment to the most exposed members of the general public due to the presence of cobalt-60 exceed 1% of the ICRP principal dose limit for members of the public (1mSv). It is concluded that existing discharge arrangements are providing effective control over environmental levels of cobalt-60, and that there has been no radiological hazard to any member of the general public during 1989 from the operation of nuclear powered submarines. These findings have been confirmed by independent monitoring undertaken by the Ministry of Agriculture, Fisheries and Food Directorate of Fisheries Research. (author)

Marine environmental radioactivity surveys at nuclear submarine berths in the UK 1991

International Nuclear Information System (INIS)

1992-06-01

This report presents the results of the marine environmental radioactivity monitoring surveys of intertidal and underwater areas around nuclear submarine berths in the UK, including the US Naval Base at Holy Loch, which were carried out by DRPS during 1991. Also included are results of smaller scale intertidal surveys carried out by local staff but co-ordinated by DRPS and, as an Appendix, a report by the US Navy detailing the results of their environmental monitoring programme at Holy Loch. Cobalt-60, the nuclide of major importance in naval discharges, was detected in a number of samples but in many cases was attributable to discharges by other operators. Concentrations in any case were found to be low, and at no survey location did the calculated annual radiation dose commitment to the most exposed members of the general public due to the presence of cobalt-60 exceed 1% of the ICRP principal dose limit for members of the public (1000 μSv). These results are consistent with those obtained in the independent monitoring programme undertaken by the Ministry of Agriculture Fisheries and Food Directorate of Fisheries Research. It is concluded that existing discharge arrangements are providing effective control over environmental levels of cobalt-60, and that there has been no radiological hazard to any member of the general public during 1991 from the operation of nuclear powered submarines. (author)

Marine environmental radioactivity surveys at nuclear submarine berths in the UK, 1990

International Nuclear Information System (INIS)

Fuller, D.; Casey, E.

1992-02-01

This report presents the results of the marine environmental radioactivity monitoring surveys of intertidal and underwater areas around nuclear submarine berths in the UK, including the US Naval Base at Holy Loch, which were carried out by Defence Radiological Protection Service (DRPS) during 1990. Also included are results of smaller scale intertidal surveys carried out by local staff but coordinated by DRPS and, as an Appendix, a report by the US Navy detailing the results of their environmental monitoring programme at Holy Loch. Cobalt-60, the nuclide of major importance in naval discharges, was detected in a number of samples but in most cases was attributable to discharges by other operators. Concentrations in any case were found to be low, and at no survey location did the calculated annual radiation dose commitment to the most exposed members of the general public due to the presence of cobalt-60 exceed 1% of the ICRP principal dose limit for members of the public (1000 μSv). These results are consistent with those obtained in the independent monitoring programme undertaken by the Ministry of Agriculture Fisheries and Food Directorate of Fisheries Research. It is concluded that existing discharge arrangements are providing effective control over environmental levels of cobalt-60, and that there has been no radiological hazard to any member of the general public during 1990 from the operation of nuclear powered submarines. (author)

Energy dissipation by submarine obstacles during landslide impact on reservoir - potentially avoiding catastrophic dam collapse

Science.gov (United States)

Kafle, Jeevan; Kattel, Parameshwari; Mergili, Martin; Fischer, Jan-Thomas; Tuladhar, Bhadra Man; Pudasaini, Shiva P.

2017-04-01

Dense geophysical mass flows such as landslides, debris flows and debris avalanches may generate super tsunami waves as they impact water bodies such as the sea, hydraulic reservoirs or mountain lakes. Here, we apply a comprehensive and general two-phase, physical-mathematical mass flow model (Pudasaini, 2012) that consists of non-linear and hyperbolic-parabolic partial differential equations for mass and momentum balances, and present novel, high-resolution simulation results for two-phase flows, as a mixture of solid grains and viscous fluid, impacting fluid reservoirs with obstacles. The simulations demonstrate that due to the presence of different obstacles in the water body, the intense flow-obstacle-interaction dramatically reduces the flow momentum resulting in the rapid energy dissipation around the obstacles. With the increase of obstacle height overtopping decreases but, the deflection and capturing (holding) of solid mass increases. In addition, the submarine solid mass is captured by the multiple obstacles and the moving mass decreases both in amount and speed as each obstacle causes the flow to deflect into two streams and also captures a portion of it. This results in distinct tsunami and submarine flow dynamics with multiple surface water and submarine debris waves. This novel approach can be implemented in open source GIS modelling framework r.avaflow, and be applied in hazard mitigation, prevention and relevant engineering or environmental tasks. This might be in particular for process chains, such as debris impacts in lakes and subsequent overtopping. So, as the complex flow-obstacle-interactions strongly and simultaneously dissipate huge energy at impact such installations potentially avoid great threat against the integrity of the dam. References: Pudasaini, S. P. (2012): A general two-phase debris flow model. J. Geophys. Res. 117, F03010, doi: 10.1029/ 2011JF002186.

Short rendezvous missions for advanced Russian human spacecraft

Science.gov (United States)

Murtazin, Rafail F.; Budylov, Sergey G.

2010-10-01

The two-day stay of crew in a limited inhabited volume of the Soyuz-TMA spacecraft till docking to ISS is one of the most stressful parts of space flight. In this paper a number of possible ways to reduce the duration of the free flight phase are considered. The duration is defined by phasing strategy that is necessary for reduction of the phase angle between the chaser and target spacecraft. Some short phasing strategies could be developed. The use of such strategies creates more comfortable flight conditions for crew thanks to short duration and additionally it allows saving spacecraft's life support resources. The transition from the methods of direct spacecraft rendezvous using one orbit phasing (first flights of " Vostok" and " Soyuz" vehicles) to the currently used methods of two-day rendezvous mission can be observed in the history of Soviet manned space program. For an advanced Russian human rated spacecraft the short phasing strategy is recommended, which can be considered as a combination between the direct and two-day rendezvous missions. The following state of the art technologies are assumed available: onboard accurate navigation; onboard computations of phasing maneuvers; launch vehicle with high accuracy injection orbit, etc. Some operational requirements and constraints for the strategies are briefly discussed. In order to provide acceptable phase angles for possible launch dates the experience of the ISS altitude profile control can be used. As examples of the short phasing strategies, the following rendezvous missions are considered: direct ascent, short mission with the phasing during 3-7 orbits depending on the launch date (nominal or backup). For each option statistical modeling of the rendezvous mission is fulfilled, as well as an admissible phase angle range, accuracy of target state vector and addition fuel consumption coming out of emergency is defined. In this paper an estimation of pros and cons of all options is conducted.

Tsunami run-up and inundation along the coast of Sabah and Sarawak, Malaysia due to a potential Brunei submarine mass failure.

Science.gov (United States)

Tan, Wai Kiat; Teh, Su Yean; Koh, Hock Lye

2017-07-01

Submarine landslides, also known as submarine mass failures (SMFs), are major natural marine disasters that could critically damage coastal facilities such as nuclear power plants and oil and gas platforms. It is therefore essential to investigate submarine landslides for potential tsunami hazard assessment. Three-dimensional seismic data from offshore Brunei have revealed a giant seabed mass deposited by a previous SMF. The submarine mass extends over 120 km from the continental slope of the Baram Canyon at 200 m water depth to the deep basin floor of the Northwest Borneo Trough. A suite of in-house two-dimensional depth-averaged tsunami simulation model TUNA (Tsunami-tracking Utilities and Application) is developed to assess the vulnerability of coastal communities in Sabah and Sarawak subject to potential SMF tsunami. The submarine slide is modeled as a rigid body moving along a planar slope with the center of mass motion parallel to the planar slope and subject to external forces due to added mass, gravity, and dissipation. The nonlinear shallow water equations are utilized to simulate tsunami propagation from deepwater up to the shallow offshore areas. A wetting-drying algorithm is used when a tsunami wave reaches the shoreline to compute run up of tsunami along the shoreline. Run-up wave height and inundation maps are provided for seven densely populated locations in Sabah and Sarawak to highlight potential risks at each location, subject to two scenarios of slide slopes: 2° and 4°. The first wave may arrive at Kudat as early as 0.4 h after the SMF, giving local communities little time to evacuate. Over a small area, maximum inundated depths reaching 20.3 m at Kudat, 26.1 m at Kota Kinabalu, and 15.5 m at Miri are projected, while the maximum inundation distance of 4.86 km is expected at Miri due to its low-lying coast. In view of the vulnerability of some locations to the SMF tsunami, it is important to develop and implement community resilience

The Problems of implementation of the European Union directives for electrical and electronic equipment hazardousness

OpenAIRE

Vaišvila, Anicetas; Vaičikonis, Eduardas

2006-01-01

The problems of implementation of two new EU Directives is discussed in this article. It is so called WEEE (Waste Electrical and Electronic Equipment) and RoHS (Restriction of use of certain Hazardous Substances in electrical and electronic equipment), as well as influence of these directives to quality and environmental management systems. The RoHS directive requires a number of potentially hazardous substances (lead, mercury, cadmium, hexavalent chromium, polybrominated byphenyls (PBB) and ...

Direct Problem-Based Learning (DPBL): A Framework for Integrating Direct Instruction and Problem-Based Learning Approach

Science.gov (United States)

Winarno, Sri; Muthu, Kalaiarasi Sonai; Ling, Lew Sook

2018-01-01

Direct instruction approach has been widely used in higher education. Many studies revealed that direct instruction improved students' knowledge. The characteristics of direct instruction include the subject delivered through face-to-face interaction with the lecturers and materials that sequenced deliberately and taught explicitly. However,…

Geologic siting considerations for the disposal of radioactive waste into submarine geologic formations

International Nuclear Information System (INIS)

Hollister, C.D.

1979-01-01

The most desirable characteristics of the host medium are: (1) low permeability and high Kd; (2) ability to self heal, i.e., be visco-elastic in response to dynamic stress; (3) stability under predicted thermal loading; (4) a low content of organic matter, i.e., be well oxidized. The submarine geologic formation that appears to best satisfy the above criteria is abyssal red clay. Depending on organic interactions and permeability considerations, light brown deep-sea clays with 20 to 40% CaCO 3 also may be suitable. Increasingly organic-rich, more permeable biogenic oozes appear less suitable, with turbidite sands and silts least desirable of all. Ocean regions excluded at the present time are: (1) areas less than 4000 meters deep; (2) the continental margin including fans, deltas, aprons, cones; (3) proximal portions of abyssal plains; (4) all fracture zone abyssal plains; (5) all submarine canyon-levee systems; (6) areas covered with less than 50 meters of sediment; (7) areas greater than 100 nautical miles from plate boundaries; (8) areas with ice-rafted debris; (9) major shipping lanes, cable routes and defense installations; (10) seafloor regions below areas of high biological productivity; and (11) approximately one third of the world's ocean floor satisfy these criteria

Bathymetric mapping of submarine sand waves using multiangle sun glitter imagery: a case of the Taiwan Banks with ASTER stereo imagery

Science.gov (United States)

Zhang, Hua-guo; Yang, Kang; Lou, Xiu-lin; Li, Dong-ling; Shi, Ai-qin; Fu, Bin

2015-01-01

Submarine sand waves are visible in optical sun glitter remote sensing images and multiangle observations can provide valuable information. We present a method for bathymetric mapping of submarine sand waves using multiangle sun glitter information from Advanced Spaceborne Thermal Emission and Reflection Radiometer stereo imagery. Based on a multiangle image geometry model and a sun glitter radiance transfer model, sea surface roughness is derived using multiangle sun glitter images. These results are then used for water depth inversions based on the Alpers-Hennings model, supported by a few true depth data points (sounding data). Case study results show that the inversion and true depths match well, with high-correlation coefficients and root-mean-square errors from 1.45 to 2.46 m, and relative errors from 5.48% to 8.12%. The proposed method has some advantages over previous methods in that it requires fewer true depth data points, it does not require environmental parameters or knowledge of sand-wave morphology, and it is relatively simple to operate. On this basis, we conclude that this method is effective in mapping submarine sand waves and we anticipate that it will also be applicable to other similar topography types.

Initial studies of submarine groundwater discharge in Mississippi coastal waters

Science.gov (United States)

Shiller, A. M.; Moore, W. S.; Joung, D. J.; Box, H.; Ho, P.; Whitmore, L. M.; Gilbert, M.; Anderson, H.

2017-12-01

Submarine groundwater discharge (SGD) is a critical component of coastal ecosystems, affecting biogeochemistry and productivity. The SGD flux and effect on the ecosystem of the Mississippi (MS) Bight has not previously been studied. We have determined Ba, δ18O of water, and Ra-isotopes, together with nutrients, chlorophyll, and dissolved oxygen (DO) during multiple cruises from fall 2015 to summer 2016. Water isotope distributions (δ18O) show that, although the MS River Delta bounds the western side of the Bight, nonetheless, Mobile Bay and other local rivers are the Bight's dominant freshwater sources. But elevated dissolved Ba and Ra isotopes cannot be explained by river input. Spatially, SGD in the MS Bight occurs over a wide area, with hot spots near the barrier islands (e.g., Chandeleurs, Horn and Dauphin Islands) and the mouth of Mobile Bay, probably in association with old buried river channels, or dredged ship channels. Based on their high concentrations in saline groundwaters sampled on the barrier islands, the elevated Ba and Ra in MS Bight water are likely due to SGD. In subsurface waters, long-lived Ra isotopes were negatively correlated with DO during spring and summer 2016, suggesting direct discharge of DO-depleted groundwater and/or accumulation of SGD-derived Ra and microbial DO consumption under strongly stratified conditions. Our ongoing study suggests that seasonal variability in flushing, water stratification, and SGD input play important roles in biological production and bottom water hypoxia in the MS Bight.

Earthquakes drive large-scale submarine canyon development and sediment supply to deep-ocean basins.

Science.gov (United States)

Mountjoy, Joshu J; Howarth, Jamie D; Orpin, Alan R; Barnes, Philip M; Bowden, David A; Rowden, Ashley A; Schimel, Alexandre C G; Holden, Caroline; Horgan, Huw J; Nodder, Scott D; Patton, Jason R; Lamarche, Geoffroy; Gerstenberger, Matthew; Micallef, Aaron; Pallentin, Arne; Kane, Tim

2018-03-01

Although the global flux of sediment and carbon from land to the coastal ocean is well known, the volume of material that reaches the deep ocean-the ultimate sink-and the mechanisms by which it is transferred are poorly documented. Using a globally unique data set of repeat seafloor measurements and samples, we show that the moment magnitude ( M w ) 7.8 November 2016 Kaikōura earthquake (New Zealand) triggered widespread landslides in a submarine canyon, causing a powerful "canyon flushing" event and turbidity current that traveled >680 km along one of the world's longest deep-sea channels. These observations provide the first quantification of seafloor landscape change and large-scale sediment transport associated with an earthquake-triggered full canyon flushing event. The calculated interevent time of ~140 years indicates a canyon incision rate of 40 mm year -1 , substantially higher than that of most terrestrial rivers, while synchronously transferring large volumes of sediment [850 metric megatons (Mt)] and organic carbon (7 Mt) to the deep ocean. These observations demonstrate that earthquake-triggered canyon flushing is a primary driver of submarine canyon development and material transfer from active continental margins to the deep ocean.

A Coral Reef Algorithm Based on Learning Automata for the Coverage Control Problem of Heterogeneous Directional Sensor Networks.

Science.gov (United States)

Li, Ming; Miao, Chunyan; Leung, Cyril

2015-12-04

Coverage control is one of the most fundamental issues in directional sensor networks. In this paper, the coverage optimization problem in a directional sensor network is formulated as a multi-objective optimization problem. It takes into account the coverage rate of the network, the number of working sensor nodes and the connectivity of the network. The coverage problem considered in this paper is characterized by the geographical irregularity of the sensed events and heterogeneity of the sensor nodes in terms of sensing radius, field of angle and communication radius. To solve this multi-objective problem, we introduce a learning automata-based coral reef algorithm for adaptive parameter selection and use a novel Tchebycheff decomposition method to decompose the multi-objective problem into a single-objective problem. Simulation results show the consistent superiority of the proposed algorithm over alternative approaches.

Grains of Nonferrous and Noble Metals in Iron-Manganese Formations and Igneous Rocks of Submarine Elevations of the Sea of Japan

Science.gov (United States)

Kolesnik, O. N.; Astakhova, N. V.

2018-01-01

Iron-manganese formations and igneous rocks of submarine elevations in the Sea of Japan contain overlapping mineral phases (grains) with quite identical morphology, localization, and chemical composition. Most of the grains conform to oxides, intermetallic compounds, native elements, sulfides, and sulfates in terms of the set of nonferrous, noble, and certain other metals (Cu, Zn, Sn, Pb, Ni, Mo, Ag, Pd, and Pt). The main conclusion that postvolcanic hydrothermal fluids are the key sources of metals is based upon a comparison of the data of electron microprobe analysis of iron-manganese formations and igneous rocks dredged at the same submarine elevations in the Sea of Japan.

Topic Modeling of NASA Space System Problem Reports: Research in Practice

Science.gov (United States)

Layman, Lucas; Nikora, Allen P.; Meek, Joshua; Menzies, Tim

2016-01-01

Problem reports at NASA are similar to bug reports: they capture defects found during test, post-launch operational anomalies, and document the investigation and corrective action of the issue. These artifacts are a rich source of lessons learned for NASA, but are expensive to analyze since problem reports are comprised primarily of natural language text. We apply topic modeling to a corpus of NASA problem reports to extract trends in testing and operational failures. We collected 16,669 problem reports from six NASA space flight missions and applied Latent Dirichlet Allocation topic modeling to the document corpus. We analyze the most popular topics within and across missions, and how popular topics changed over the lifetime of a mission. We find that hardware material and flight software issues are common during the integration and testing phase, while ground station software and equipment issues are more common during the operations phase. We identify a number of challenges in topic modeling for trend analysis: 1) that the process of selecting the topic modeling parameters lacks definitive guidance, 2) defining semantically-meaningful topic labels requires nontrivial effort and domain expertise, 3) topic models derived from the combined corpus of the six missions were biased toward the larger missions, and 4) topics must be semantically distinct as well as cohesive to be useful. Nonetheless,topic modeling can identify problem themes within missions and across mission lifetimes, providing useful feedback to engineers and project managers.

Continuity of the direct and inverse problems in one-dimensional scattering theory and numerical solution of the inverse problem

International Nuclear Information System (INIS)

Moura, C.A. de.

1976-09-01

We propose an algorithm for computing the potential V(x) associated to the one-dimensional Schroedinger operator E identical to - d 2 /dx 2 + V(x) -infinite < x< infinite from knowledge of the S.matrix, more exactly, of one of the reelection coefficients. The convergence of the algorithm is guaranteed by the stability results obtained for both the direct and inverse problems

Direct and inverse problems in dispersive time-of-flight photocurrent revisited

Science.gov (United States)

Sagues, Francesc; Sokolov, Igor M.

2017-10-01

Using the fact that the continuous time random walk (CTRW) scheme is a random process subordinated to a simple random walk under the operational time given by the number of steps taken by the walker up to a given time, we revisit the problem of strongly dispersive transport in disordered media, which first lead Scher and Montroll to introducing the power law waiting time distributions. Using a subordination approach permits to disentangle the complexity of the problem, separating the solution of the boundary value problem (which is solved on the level of normal diffusive transport) from the influence of the waiting times, which allows for the solution of the direct problem in the whole time domain (including short times, out of reach of the initial approach), and simplifying strongly the analysis of the inverse problem. This analysis shows that the current traces do not contain information sufficient for unique restoration of the waiting time probability densities, but define a single-parametric family of functions that can be restored, all leading to the same photocurrent forms. The members of the family have the power-law tails which differ only by a prefactor, but may look astonishingly different at their body. The same applies to the multiple trapping model, mathematically equivalent to a special limiting case of CTRW. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

The Asteroid Redirect Mission (ARM)

Science.gov (United States)

Abell, Paul; Gates, Michele; Johnson, Lindley; Chodas, Paul; Mazanek, Dan; Reeves, David; Ticker, Ronald

2016-07-01

To achieve its long-term goal of sending humans to Mars, the National Aeronautics and Space Administration (NASA) plans to proceed in a series of incrementally more complex human spaceflight missions. Today, human flight experience extends only to Low-Earth Orbit (LEO), and should problems arise during a mission, the crew can return to Earth in a matter of minutes to hours. The next logical step for human spaceflight is to gain flight experience in the vicinity of the Moon. These cis-lunar missions provide a "proving ground" for the testing of systems and operations while still accommodating an emergency return path to the Earth that would last only several days. Cis-lunar mission experience will be essential for more ambitious human missions beyond the Earth-Moon system, which will require weeks, months, or even years of transit time. In addition, NASA has been given a Grand Challenge to find all asteroid threats to human populations and know what to do about them. Obtaining knowledge of asteroid physical properties combined with performing technology demonstrations for planetary defense provide much needed information to address the issue of future asteroid impacts on Earth. Hence the combined objectives of human exploration and planetary defense give a rationale for the Asteroid Re-direct Mission (ARM). Mission Description: NASA's ARM consists of two mission segments: 1) the Asteroid Redirect Robotic Mission (ARRM), the first robotic mission to visit a large (greater than ~100 m diameter) near-Earth asteroid (NEA), collect a multi-ton boulder from its surface along with regolith samples, demonstrate a planetary defense technique, and return the asteroidal material to a stable orbit around the Moon; and 2) the Asteroid Redirect Crewed Mission (ARCM), in which astronauts will take the Orion capsule to rendezvous and dock with the robotic vehicle, conduct multiple extravehicular activities to explore the boulder, and return to Earth with samples. NASA's proposed

Submarine groundwater discharge into the coast revealed by water chemistry of man-made undersea liquefied petroleum gas cavern

Science.gov (United States)

Lee, Jin-Yong; Cho, Byung Wook

2008-10-01

SummaryThe occurrence of submarine groundwater discharge (SGD) as well as its supply of many nutrients and metals to coastal seawaters is now generally known. However, previous studies have focused on the chemical and radiological analysis of groundwater, surface seawater, shallow marine sediments and their pore waters, as well as the measurement of upward flow through the marine sediments, as end members of the discharge process. In this study, chemical and isotopic analysis results of marine subsurface waters are reported. These were obtained from deep boreholes of an undersea liquefied petroleum gas (LPG) storage cavern, located about 8 km off the western coast of Korea. The cavern is about 130-150 m below the sea bottom, which is covered by a 4.8-19.5 m silty clay stratum. An isotopic composition (δ 2H and δ 18O) of the marine subsurface waters falls on a mixing line between terrestrial groundwater and seawater. Vertical EC profiling at the cavern boreholes revealed the existence of a fresh water zone. An increase in the contents of ferrous iron and manganese and a decrease in levels of nitrate, bicarbonate and cavern seepage were recorded in August 2006, indicating a decreased submarine groundwater flux originating from land, mainly caused by an elevated cavern gas pressure. It is suggested in this study that the main source of fresh waters in the man-made undersea cavern is the submarine groundwater discharge mainly originating from the land.

Application of direct discrete method (DDM) to multigroup neutron transport problems

International Nuclear Information System (INIS)

Vosoughi, Naser; Salehi, Ali Akbar; Shahriari, Majid

2003-01-01

The Direct Discrete Method (DDM), which produced excellent results for one-group neutron transport problems, has been developed for multigroup energy. A multigroup neutron transport discrete equation has been produced for a cylindrical shape fuel element with and without associated coolant regions with two boundary conditions. The calculations are illustrated for two-group energy by graphs showing the fast and thermal fluxes. The validity of the results are tested against the results obtained by the ANISN code. (author)

INTEGRITY -- Integrated Human Exploration Mission Simulation Facility

Science.gov (United States)

Henninger, D.; Tri, T.; Daues, K.

It is proposed to develop a high -fidelity ground facil ity to carry out long-duration human exploration mission simulations. These would not be merely computer simulations - they would in fact comprise a series of actual missions that just happen to stay on earth. These missions would include all elements of an actual mission, using actual technologies that would be used for the real mission. These missions would also include such elements as extravehicular activities, robotic systems, telepresence and teleoperation, surface drilling technology--all using a simulated planetary landscape. A sequence of missions would be defined that get progressively longer and more robust, perhaps a series of five or six missions over a span of 10 to 15 years ranging in durat ion from 180 days up to 1000 days. This high-fidelity ground facility would operate hand-in-hand with a host of other terrestrial analog sites such as the Antarctic, Haughton Crater, and the Arizona desert. Of course, all of these analog mission simulations will be conducted here on earth in 1-g, and NASA will still need the Shuttle and ISS to carry out all the microgravity and hypogravity science experiments and technology validations. The proposed missions would have sufficient definition such that definitive requirements could be derived from them to serve as direction for all the program elements of the mission. Additionally, specific milestones would be established for the "launch" date of each mission so that R&D programs would have both good requirements and solid milestones from which to build their implementation plans. Mission aspects that could not be directly incorporated into the ground facility would be simulated via software. New management techniques would be developed for evaluation in this ground test facility program. These new techniques would have embedded metrics which would allow them to be continuously evaluated and adjusted so that by the time the sequence of missions is completed

Mission Specialist Scott Parazynski arrives late at KSC

Science.gov (United States)

1998-01-01

The T-38 jet aircraft arrives at the Shuttle Landing Facility carrying STS-95 Mission Specialist Scott E. Parazynski (second seat). The pilot is astronaut Kent Rominger. Parazynski's first plane experienced problems at the stop at Tyndall AFB and he had to wait for another jet and pilot to finish the flight to KSC. He joined other crewmembers Mission Commander Curtis L. Brown Jr., Pilot Steven W. Lindsey, Mission Specialist Stephen K. Robinson, Payload Specialist John H. Glenn Jr., senator from Ohio, Mission Specialist Pedro Duque, with the European Space Agency (ESA), and Payload Specialist Chiaki Mukai, with the National Space Development Agency of Japan (NASDA), for final pre-launch preparations. STS-95 is expected to launch at 2 p.m. EST on Oct. 29, last 8 days, 21 hours and 49 minutes, and land at 11:49 a.m. EST on Nov. 7.

Mission analysis report for the Hanford Tanks Initiative

International Nuclear Information System (INIS)

Schaus, P.S.

1997-01-01

This mission analysis report for the Hanford Tanks Initiative (HTI) supports the Hanford Site's Single-Shell Tank (SST) Waste Retrieval Program in its commitment to remove waste from the SSTs for treatment and final closure of the tanks. The results of the HTI will support the US Department of Energy's (DOE) privatization of retrieval efforts. This report addresses the HTI problem statement: Alternative technologies to past practice sluicing (PPS) have not yet been demonstrated to remove the hard heel from a sluiced tank or to remove waste from a leaking SST. Nor have performance-based criteria for cleanout and closure been demonstrated to the degree necessary to validate them as technically and economically achievable. This report also defines the mission statement and mission boundaries; the known interfaces, both programmatic and project; the mission level requirements; the test and evaluation methodology; and measures of success

Massively Clustered CubeSats NCPS Demo Mission

Science.gov (United States)

Robertson, Glen A.; Young, David; Kim, Tony; Houts, Mike

2013-01-01

Technologies under development for the proposed Nuclear Cryogenic Propulsion Stage (NCPS) will require an un-crewed demonstration mission before they can be flight qualified over distances and time frames representative of a crewed Mars mission. In this paper, we describe a Massively Clustered CubeSats platform, possibly comprising hundreds of CubeSats, as the main payload of the NCPS demo mission. This platform would enable a mechanism for cost savings for the demo mission through shared support between NASA and other government agencies as well as leveraged commercial aerospace and academic community involvement. We believe a Massively Clustered CubeSats platform should be an obvious first choice for the NCPS demo mission when one considers that cost and risk of the payload can be spread across many CubeSat customers and that the NCPS demo mission can capitalize on using CubeSats developed by others for its own instrumentation needs. Moreover, a demo mission of the NCPS offers an unprecedented opportunity to invigorate the public on a global scale through direct individual participation coordinated through a web-based collaboration engine. The platform we describe would be capable of delivering CubeSats at various locations along a trajectory toward the primary mission destination, in this case Mars, permitting a variety of potential CubeSat-specific missions. Cameras on various CubeSats can also be used to provide multiple views of the space environment and the NCPS vehicle for video monitoring as well as allow the public to "ride along" as virtual passengers on the mission. This collaborative approach could even initiate a brand new Science, Technology, Engineering and Math (STEM) program for launching student developed CubeSat payloads beyond Low Earth Orbit (LEO) on future deep space technology qualification missions. Keywords: Nuclear Propulsion, NCPS, SLS, Mars, CubeSat.

Synthesis report about the after-mine mission; Rapport de synthese sur la mission apres-mine

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The French ministry of economy finances and industry has assigned the mission of evaluating the after-mine management system to the general inspection of finances and the general council of mines. The after-mine management system encompasses all procedures of coal, iron and potash mines closing down, land reclamation and environmental remedial action and site rehabilitation. This document makes first a status of the problems generated by the stoppage of mining activities: technical aspects, costs, institutional, organisational and juridical aspects, conservation of competences, international benchmarking elements and good practices implemented in foreign countries. Then, in a second part, this report presents the recommendations of the after-mine mission about the mastery of after-mine costs in agreement with the respect of the technical and social goals, with the development of the after-mine institutional system with the scheduled disappearance of Charbonnages de France and Mines de Potasses d'Alsace companies, and with the conservation of competences in the framework of the post-mine operational structure proposed by the mission. (J.S.)

Synthesis report about the after-mine mission; Rapport de synthese sur la mission apres-mine

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The French ministry of economy finances and industry has assigned the mission of evaluating the after-mine management system to the general inspection of finances and the general council of mines. The after-mine management system encompasses all procedures of coal, iron and potash mines closing down, land reclamation and environmental remedial action and site rehabilitation. This document makes first a status of the problems generated by the stoppage of mining activities: technical aspects, costs, institutional, organisational and juridical aspects, conservation of competences, international benchmarking elements and good practices implemented in foreign countries. Then, in a second part, this report presents the recommendations of the after-mine mission about the mastery of after-mine costs in agreement with the respect of the technical and social goals, with the development of the after-mine institutional system with the scheduled disappearance of Charbonnages de France and Mines de Potasses d'Alsace companies, and with the conservation of competences in the framework of the post-mine operational structure proposed by the mission. (J.S.)

Software engineering processes for Class D missions

Science.gov (United States)

Killough, Ronnie; Rose, Debi

2013-09-01

Software engineering processes are often seen as anathemas; thoughts of CMMI key process areas and NPR 7150.2A compliance matrices can motivate a software developer to consider other career fields. However, with adequate definition, common-sense application, and an appropriate level of built-in flexibility, software engineering processes provide a critical framework in which to conduct a successful software development project. One problem is that current models seem to be built around an underlying assumption of "bigness," and assume that all elements of the process are applicable to all software projects regardless of size and tolerance for risk. This is best illustrated in NASA's NPR 7150.2A in which, aside from some special provisions for manned missions, the software processes are to be applied based solely on the criticality of the software to the mission, completely agnostic of the mission class itself. That is, the processes applicable to a Class A mission (high priority, very low risk tolerance, very high national significance) are precisely the same as those applicable to a Class D mission (low priority, high risk tolerance, low national significance). This paper will propose changes to NPR 7150.2A, taking mission class into consideration, and discuss how some of these changes are being piloted for a current Class D mission—the Cyclone Global Navigation Satellite System (CYGNSS).

Advances in Distributed Operations and Mission Activity Planning for Mars Surface Exploration

Science.gov (United States)

Fox, Jason M.; Norris, Jeffrey S.; Powell, Mark W.; Rabe, Kenneth J.; Shams, Khawaja

2006-01-01

A centralized mission activity planning system for any long-term mission, such as the Mars Exploration Rover Mission (MER), is completely infeasible due to budget and geographic constraints. A distributed operations system is key to addressing these constraints; therefore, future system and software engineers must focus on the problem of how to provide a secure, reliable, and distributed mission activity planning system. We will explain how Maestro, the next generation mission activity planning system, with its heavy emphasis on portability and distributed operations has been able to meet these design challenges. MER has been an excellent proving ground for Maestro's new approach to distributed operations. The backend that has been developed for Maestro could benefit many future missions by reducing the cost of centralized operations system architecture.

Global astrometry with the space interferometry mission

Science.gov (United States)

Boden, A.; Unwin, S.; Shao, M.

1997-01-01

The prospects for global astrometric measurements with the space interferometry mission (SIM) are discussed. The SIM mission will perform four microarcsec astrometric measurements on objects as faint as 20 mag using the optical interferometry technique with a 10 m baseline. The SIM satellite will perform narrow angle astrometry and global astrometry by means of an astrometric grid. The sensitivities of the SIM global astrometric performance and the grid accuracy versus instrumental parameters and sky coverage schemes are reported on. The problems in finding suitable astrometric grid objects to support microarcsec astrometry, and related ground-based observation programs are discussed.

About the accident of the american nuclear propulsion submarine Uss Hartford

International Nuclear Information System (INIS)

Leprieur, F.; Guillevic, J.; Alferes, M.L.; Thebault, H.; Lemaitre, N.

2004-01-01

On the 25. october 2003, the submarine had hit the bottom of the sea. The tightness of the ship and the reactor did not be affected. As a precaution, the Office of environment of Corsica has required a campaign of radioactivity analysis in the area of the natural reserve of the mouths of Bonifacio. The results of the measurements made on the 18.november were comparable to the ones made regularly on the samples coming from Bastia and Ajaccio sampling stations. This article presents an extract of the results of the analysis campaign made by the I.R.S.N. (N.C.)

High-Resolution Topographic Analyses of Mounds in Southern Acidalia Planitia, Mars: Implications for Possible Mud Volcanism in Submarine and Subaerial Environments

Directory of Open Access Journals (Sweden)

Ryodo Hemmi

2018-04-01

Full Text Available A northern ocean of Mars is still debated and, if it existed, it may have accompanied valley networks and/or outflow channels, which may have led to the emplacement of a large amount of water to the northern lowlands during the Noachian and/or Hesperian times. However, it is unclear how and under what conditions (submarine or subaerial geologic features such as mounds and giant polygons formed in the northern lowlands. The densely-distributed mounds in Chryse and Acidalia Planitia, >1000 km-wide basins of the northern plains, were suggested to be ancient mud volcanoes formed in an aqueous setting, which is controversial (i.e., mud vs. igneous and submarine vs. subaerial. However, these mounds have not been quantitatively well characterized, particularly with respect to their detailed topography. Here we generated forty digital elevation models (DEMs with resolution of up to 1 m/pixel from High Resolution Imaging Science Experiment (HiRISE stereo image pairs, and we accurately measured the morphometric parameters of ~1300 mounds within the southern part of the Acidalia basin. Their heights and diameters resulted in good accordance with those of mud and igneous volcanoes in submarine/subaerial settings on Earth. Maximum depths of their source reservoirs vary from ~30 to ~450 m for a subaqueous setting and from ~110 to ~860 m for a subaerial setting, both of which are consistent with fluid expulsion from the ~100–4500 m-thick flood deposits (Vastitas Borealis Formation, VBF. On the basis of the morphometric values, we estimated rheological properties of materials forming the mounds and found them consistent with a mud flow origin, which does not rule out an igneous origin. The conditions of possible submarine mud or igneous volcanoes may have harbored less hazardous environments for past life on Mars than those on an ocean-free surface.

Complementary results of radioactivity analysis made in Corsica following the navigation incident of the Uss Hartford submarine

International Nuclear Information System (INIS)

2004-01-01

The results of analysis made by the Institute of radiation protection and nuclear safety in the area of the Bonifacio estuary do not reveal any increase of artificial radioactivity following the navigation incident of the Uss Hartford submarine. They confirm the previous published results. (N.C.)

INIR: Integrated Nuclear Infrastructure Review Missions. Guidance on Preparing and Conducting INIR Missions (Rev. 1)

International Nuclear Information System (INIS)

2011-04-01

The IAEA's Integrated Nuclear Infrastructure Review (INIR) missions are designed to assist Member States, at their request, in evaluating the status of their national infrastructure for the introduction of a nuclear power programme. Each INIR mission is coordinated and led by the IAEA and conducted by a team of international experts drawn from Member States who have experience in different aspects of developing and deploying nuclear infrastructure. The IAEA publication Milestones in the Development of a National Infrastructure for Nuclear Power (IAEA Nuclear Energy Series No. NG-G-3.1) contains a description of 19 infrastructure issues to be considered during the different stages of development of a nuclear power programme. The starting point for an INIR mission is a self-evaluation performed by the Member State against these infrastructure issues. Following the self-evaluation, the INIR mission reviews the status of the national nuclear infrastructure, identifies existing gaps in specific infrastructure-related areas and proposes recommendations to fill these gaps. The INIR mission provides Member State representatives with an opportunity to have in depth discussions with international experts about experiences and best practices in different countries. In developing its recommendations, the INIR team takes into account the comments made by the relevant national organizations. Implementation of any of the team's recommendations is at the discretion of the Member State requesting the mission. The results of the INIR mission are expected to help the Member State to develop an action plan to fill any gaps, which in turn will help the development of the national nuclear infrastructure. The IAEA stands ready to assist, as requested and appropriate, in the different steps of this action plan. This guidance publication is directed to assist in preparing and conducting the INIR missions. It was developed under the coordination of the IAEA Integrated Nuclear Infrastructure

Performance analyses of naval ships based on engineering level of simulation at the initial design stage

Directory of Open Access Journals (Sweden)

Dong-Hoon Jeong

2017-07-01

Full Text Available Naval ships are assigned many and varied missions. Their performance is critical for mission success, and depends on the specifications of the components. This is why performance analyses of naval ships are required at the initial design stage. Since the design and construction of naval ships take a very long time and incurs a huge cost, Modeling and Simulation (M & S is an effective method for performance analyses. Thus in this study, a simulation core is proposed to analyze the performance of naval ships considering their specifications. This simulation core can perform the engineering level of simulations, considering the mathematical models for naval ships, such as maneuvering equations and passive sonar equations. Also, the simulation models of the simulation core follow Discrete EVent system Specification (DEVS and Discrete Time System Specification (DTSS formalisms, so that simulations can progress over discrete events and discrete times. In addition, applying DEVS and DTSS formalisms makes the structure of simulation models flexible and reusable. To verify the applicability of this simulation core, such a simulation core was applied to simulations for the performance analyses of a submarine in an Anti-SUrface Warfare (ASUW mission. These simulations were composed of two scenarios. The first scenario of submarine diving carried out maneuvering performance analysis by analyzing the pitch angle variation and depth variation of the submarine over time. The second scenario of submarine detection carried out detection performance analysis by analyzing how well the sonar of the submarine resolves adjacent targets. The results of these simulations ensure that the simulation core of this study could be applied to the performance analyses of naval ships considering their specifications.

The Spartan 1 mission

Science.gov (United States)

Cruddace, Raymond G.; Fritz, G. G.; Shrewsberry, D. J.; Brandenstein, D. J.; Creighton, D. C.; Gutschewski, G.; Lucid, S. W.; Nagel, J. M.; Fabian, J. M.; Zimmerman, D.

1989-01-01

The first Spartan mission is documented. The Spartan program, an outgrowth of a joint Naval Research Laboratory (NRL)/National Aeronautics and Space Administration (NASA)-Goddard Space Flight Center (GSFC) development effort, was instituted by NASA for launching autonomous, recoverable payloads from the space shuttle. These payloads have a precise pointing system and are intended to support a wide range of space-science observations and experiments. The first Spartan, carrying an NRL X-ray astronomy instrument, was launched by the orbiter Discovery (STS51G) on June 20, 1985 and recovered successfully 45 h later, on June 22. During this period, Spartan 1 conducted a preprogrammed series of observations of two X-ray sources: the Perseus cluster of galaxies and the center of our galaxy. The mission was successful from both on engineering and a scientific viewpoint. Only one problem was encountered, the attitude control system (ACS) shut down earlier than planned because of high attitude control system gas consumption. A preplanned emergency mode then placed Spartan 1 into a stable, safe condition and allowed a safe recovery. The events are described of the mission and presents X-ray maps of the two observed sources, which were produced from the flight data.

The Importance of Submarine Tenders to a Modern Naval War: Naval Combat Logistics and Seabasing

Science.gov (United States)

2017-04-28

concern of political risk or consequences of sovereignty . 15. SUBJECT TERMS TENDER, SEABASING, SUBMARINE MAINTENANCE, NAVAL COMBAT LOGISTICS...anywhere in the world’s oceans, with minimal concern of political risk or consequences of sovereignty . 1 INTRODUCTION...logistics beyond the basic peacetime considerations of food and fuel. If a maritime conflict occurs in a distant theatre, the Navy will find that it

Dynamics of submarine groundwater discharge and associated fluxes of dissolved nutrients, carbon, and trace gases to the coastal zone (Okatee River estuary, South Carolina)

Science.gov (United States)

Porubsky, W.P.; Weston, N.B.; Moore, W.S.; Ruppel, C.; Joye, S.B.

2014-01-01

Multiple techniques, including thermal infrared aerial remote sensing, geophysical and geological data, geochemical characterization and radium isotopes, were used to evaluate the role of groundwater as a source of dissolved nutrients, carbon, and trace gases to the Okatee River estuary, South Carolina. Thermal infrared aerial remote sensing surveys illustrated the presence of multiple submarine groundwater discharge sites in Okatee headwaters. Significant relationships were observed between groundwater geochemical constituents and 226Ra activity in groundwater with higher 226Ra activity correlated to higher concentrations of organics, dissolved inorganic carbon, nutrients, and trace gases to the Okatee system. A system-level radium mass balance confirmed a substantial submarine groundwater discharge contribution of these constituents to the Okatee River. Diffusive benthic flux measurements and potential denitrification rate assays tracked the fate of constituents in creek bank sediments. Diffusive benthic fluxes were substantially lower than calculated radium-based submarine groundwater discharge inputs, showing that advection of groundwater-derived nutrients dominated fluxes in the system. While a considerable potential for denitrification in tidal creek bank sediments was noted, in situ denitrification rates were nitrate-limited, making intertidal sediments an inefficient nitrogen sink in this system. Groundwater geochemical data indicated significant differences in groundwater chemical composition and radium activity ratios between the eastern and western sides of the river; these likely arose from the distinct hydrological regimes observed in each area. Groundwater from the western side of the Okatee headwaters was characterized by higher concentrations of dissolved organic and inorganic carbon, dissolved organic nitrogen, inorganic nutrients and reduced metabolites and trace gases, i.e. methane and nitrous oxide, than groundwater from the eastern side

Collaboration support system for "Phobos-Soil" space mission.

Science.gov (United States)

Nazarov, V.; Nazirov, R.; Zakharov, A.

2009-04-01

Rapid development of communication facilities leads growth of interactions done via electronic means. However we can see some paradox in this segment in last times: Extending of communication facilities increases collaboration chaos. And it is very sensitive for space missions in general and scientific space mission particularly because effective decision of this task provides successful realization of the missions and promises increasing the ratio of functional characteristic and cost of mission at all. Resolving of this problem may be found by using respective modern technologies and methods which widely used in different branches and not in the space researches only. Such approaches as Social Networking, Web 2.0 and Enterprise 2.0 look most prospective in this context. The primary goal of the "Phobos-Soil" mission is an investigation of the Phobos which is the Martian moon and particularly its regolith, internal structure, peculiarities of the orbital and proper motion, as well as a number of different scientific measurements and experiments for investigation of the Martian environment. A lot of investigators involved in the mission. Effective collaboration system is key facility for information support of the mission therefore. Further to main goal: communication between users of the system, modern approaches allows using such capabilities as self-organizing community, user generated content, centralized and federative control of the system. Also it may have one unique possibility - knowledge management which is very important for space mission realization. Therefore collaboration support system for "Phobos-Soil" mission designed on the base of multilayer model which includes such levels as Communications, Announcement and Information, Data sharing and Knowledge management. The collaboration support system for "Phobos-Soil" mission will be used as prototype for prospective Russian scientific space missions and the presentation describes its architecture

Game Changing: NASA's Space Launch System and Science Mission Design

Science.gov (United States)

Creech, Stephen D.

2013-01-01

NASA s Marshall Space Flight Center (MSFC) is directing efforts to build the Space Launch System (SLS), a heavy-lift rocket that will carry the Orion Multi-Purpose Crew Vehicle (MPCV) and other important payloads far beyond Earth orbit (BEO). Its evolvable architecture will allow NASA to begin with Moon fly-bys and then go on to transport humans or robots to distant places such as asteroids and Mars. Designed to simplify spacecraft complexity, the SLS rocket will provide improved mass margins and radiation mitigation, and reduced mission durations. These capabilities offer attractive advantages for ambitious missions such as a Mars sample return, by reducing infrastructure requirements, cost, and schedule. For example, if an evolved expendable launch vehicle (EELV) were used for a proposed mission to investigate the Saturn system, a complicated trajectory would be required - with several gravity-assist planetary fly-bys - to achieve the necessary outbound velocity. The SLS rocket, using significantly higher C3 energies, can more quickly and effectively take the mission directly to its destination, reducing trip time and cost. As this paper will report, the SLS rocket will launch payloads of unprecedented mass and volume, such as "monolithic" telescopes and in-space infrastructure. Thanks to its ability to co-manifest large payloads, it also can accomplish complex missions in fewer launches. Future analyses will include reviews of alternate mission concepts and detailed evaluations of SLS figures of merit, helping the new rocket revolutionize science mission planning and design for years to come.

Geo-hazard by sediment mass movements in submarine canyons