WorldWideScience

Sample records for echolocating off-shore hourglassdolphins

  1. Feeding at a high pitch: Source parameters of narrow band,high-frequency clicks from echolocating off-shore hourglassdolphins and coastal Hector's dolphins

    DEFF Research Database (Denmark)

    Kyhn, Line Anker; Tougaard, Jakob; Jensen, Frants Havmand

    2009-01-01

    Toothed whales depend on echolocation for orientation and prey localization, and source parameters of echolocation clicks from free-ranging animals therefore convey valuable information about the acoustic physiology and behavioral ecology of the recorded species. Recordings of wild hourglass (Lag...

  2. Design off-shore wind climate

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G C; Joergensen, H E [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    Specific recommendations of off-shore turbulence intensities, applicable for design purposes, are lacking in the present IEC-code. The present off-shore wind climate analysis presents the distribution of the turbulence standard deviation around the mean turbulence standard deviation, conditioned on the mean wind speed. Measured distributions, based on a huge amount of measuring data from two shallow water off-shore sites, are parameterized by fitting to a three parameter Weibull distribution. Combining a simple heuristic load model with the parameterized probability density functions of the turbulence standard deviations, an empirical off-shore design turbulence intensity is evaluated that in average yields the same fatigue damage as the distributed turbulence intensity. The proposed off-shore design turbulence intensity is, within the IEC code framework, applicable for extreme as well as for fatigue load determination. (au)

  3. Scour Protection of Off-Shore Windmills

    DEFF Research Database (Denmark)

    Frigaard, Peter; Pedersen, Jan

    2002-01-01

    In the Eighties and Nineties wind turbines with a total rated power of app 1000 Mega watt were erected in Denmark. Today more that 13% of the electrical consumption in in Denmark is covered by electricity from wind turbines. Through, due to lack of good positions for the windmills and due...... to growing opposition against the the wind turbines, the Danish government initiated in 1999 the construction of several large off-shore wind farms....

  4. Off-shore nuclear power plant

    International Nuclear Information System (INIS)

    Nakanishi, T.

    1980-01-01

    In order to avoid losses of energy and seawater pollution an off-shore nuclear power plant is coupled with a power plant which utilizes the temperature difference between seawater and hot reactor cooling water. According to the invention the power plant has a working media loop which is separated from the nuclear power plant. The apparative equipment and the operational characteristics of the power plant are the subject of the patent. (UWI) [de

  5. Visual disamenities from off-shore wind farms in Denmark

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Dubgaard, Alex; Tranberg, Jesper

    2006-01-01

    Expansion of the off-shore wind power plays a significant role in the energy policies of many EU countries. However, off-shore wind farms create visual disamenities. These disamenities can be reduced by locating wind farms at larger distances from the coast – and accepting higher costs per k......Wh produced. Base on the choices among alternative wind farm outlays, the preferences for reducing visual disamenities of off-shore wind farms were elicited using the Choice Experiment Method. The results show a clear picture; the respondents in three independent samples are willing to pay for mowing future...... off-shore wind farms away from the shore to reduce the wind farms visibility. However, the results also denote that the preferences vary with regards to the experiences with visual disamenities of off-shore wind farms. The respondents Horns Revs sample, where the off-shore wind farm is located...

  6. Routing helicopters for crew exchanges on off-shore locations

    NARCIS (Netherlands)

    Sierksma, G.; Tijssen, G.A.

    This paper deals with a vehicle routing problem with split demands, namely the problem of determining a flight schedule for helicopters to off-shore platform locations for exchanging crew people employed on these platforms. The problem is formulated as an LP model and solved by means of a

  7. Optimization of Organic Rankine Cycles for Off-Shore Applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Larsen, Ulrik; Nguyen, Tuong-Van

    2013-01-01

    and the thermal efficiency of the cycle can be maximized. This paper is aimed at finding the most optimal ORC tailored for off-shore applications using an optimization procedure based on the genetic algorithm. Numerous working fluids are screened through, considering mainly thermal efficiency, but also other...

  8. Cardiovascular load in off-shore sailing competition.

    Science.gov (United States)

    Bernardi, M; Felici, F; Marchetti, M; Marchettoni, P

    1990-06-01

    Blood pressure, heart rate, VO2 and lactate accumulation have been measured during the hauling of ropes that, in off shore sailing, very often implies MVC isometric effort. Measures have been taken alternatively on the boat or in laboratory with a boat simulator. It appears that energy output is moderate, lactic O2 debt not relevant and blood pressure is maintained quite unchanged due to the short duration of isometric effort. Cardiovascular load is therefore not heavy and sailing can be enlisted among aerobic recreational exercises.

  9. Decolonizing through integration: Australia's off-shore island territories

    Directory of Open Access Journals (Sweden)

    Roger Wettenhall

    2016-11-01

    Full Text Available Australia’s three small off-shore island territories – Norfolk Island in the Pacific Ocean and Christmas Island and the Cocos (Keeling Islands Group in the Indian Ocean – can be seen as monuments to 19th century British-style colonization, though their early paths to development took very different courses. Their transition to the status of external territories of the Australian Commonwealth in the 20th century – early in the case of Norfolk and later in the cases of Christmas and Cocos – put them on a common path in which serious tensions emerged between local populations which sought autonomous governance and the Commonwealth government which wanted to impose governmental systems similar to those applying to mainstream Australians. This article explores the issues involved, and seeks to relate the governmental history of the three island territories to the exploration of island jurisdictions developed in island studies research.

  10. Economic valuation of the visual externalities of off-shore wind farms

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Dubgaard, Alex; Martinsen, Louise

    The primary focus of the study presented in this report is visual externalities of off-shore wind farms and the Danish population’s willingness to pay for having these ex-ternalities reduced. The investigation is part of the Danish monitoring programme for off-shore wind farms, comprising several...

  11. Modelling seabird collision risk with off-shore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, Maria; Arroyo, Gonzalo Munoz; Rosario, Jose Juan Alonso del

    2011-07-01

    Full text: Recent concern about the adverse effects of collision mortality of avian migrants at wind farms has highlighted the need to understand bird-wind turbine interactions. Here, a stochastic collision model, based on data of seabird behaviour collected on- site, is presented, as a flexible and easy to take tool to assess the collisions probabilities of off-shore wind farms in a pre-construction phase. The collision prediction model considering the wind farm area as a risk window has been constructed as a stochastic model for avian migrants, based on Monte Carlo simulation. The model calculates the probable number of birds collided per time unit. Migration volume, wind farm dimensions, vertical and horizontal distribution of the migratory passage, flight direction and avoidance rates, between other variables, are taken into account in different steps of the model as the input variables. In order to assess the weighted importance of these factors on collision probability predictions, collision probabilities obtained from the set of scenarios resulting from the different combinations of the input variables were modelled by using Generalised Additive Models. The application of this model to a hypothetical project for erecting a wind farm at the Strait of Gibraltar showed that collision probability, and consequently mortality rates, strongly depend on the values of the avoidance rates taken into account, and the distribution of birds into the different altitude layers. These parameters should be considered as priorities to be addressed in post-construction studies. (Author)

  12. Willingness to pay for reduced visual disamenities from off-shore wind farms in Denmark

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Dubgaard, Alex

    Expansion of the off-shore wind power capacity plays a significant role in the wind power strategy in many EU countries. However, off-shore wind farms are associated with visual disamenities. The disamenities can be reduced by locating the wind farms at larger distances from the coast. But......, the costs per kWh produced increase as the distance is augmented. In this paper, peoples’ willingness to pay for a reduction in the visual disamenity of off-shore wind farms is elicited using the economic valuation method Choice Experiments. The economic valuation scenario comprises the locations of 3600 MW...... and 50 km from the coast opposed to 8 km. The results also reveal that the WTP deviate strongly with regards to the age of the respondent and the experiences with off-shore wind farms. These properties of the WTP are believed to have significant policy related consequences. Keywords: Visual Disamenities...

  13. Toxicity of harbour canal sediments before dredging and after off shore disposal

    NARCIS (Netherlands)

    Van den Hurk, P.; Eertman, R.H.M.; Stronkhorst, J.

    1997-01-01

    Dredge material from an entrance waterway to the port of Rotterdam and sediments from the North Sea off-shore disposal site were tested for toxicity using three different sediment bioassays, The goals of the study were to evaluate if bioassays generate useful additional information to chemical based

  14. Influence of occupational stress on mental health among Chinese off-shore oil workers.

    Science.gov (United States)

    Chen, Wei-Qing; Wong, Tze-Wai; Yu, Tak-Sun

    2009-09-01

    To explore the influence of occupational stress on mental health in off-shore oil production. A cross-sectional survey was conducted among 561 Chinese off-shore oil workers. The workers were invited to fill in a self-administered questionnaire exploring their socio-demographic characteristics, occupational stress levels, and 12-item general health questionnaire. A hierarchical multiple regression procedure was used to assess the effects of occupational stress on mental health. After controlling for age, educational level, marital status and years of off-shore work, poor mental health was found to have a significant positive association with seven of the nine identified sources of occupational stress. They were: conflict between job and family/social life, poor development of career and achievement at work, safety problems at work, management problems and poor relationship with others at work, poor physical environment of the work place, uncomfortable ergonomic factors at work, and poor organizational structure at work. All of these occupational stress sources together explained 19.9% of the total variance. The results confirmed that occupational stress was a major risk factor for poor mental health among Chinese off-shore oil workers. Reducing or eliminating occupational stressors at work would benefit workers' mental health.

  15. Data report of the first cruise of the Marion Off-shore Ecological Study (MOES-1)

    CSIR Research Space (South Africa)

    Duncombe-Rae, CM

    1989-01-01

    Full Text Available The first cruise of the Marion Off-shore Ecological Study (MOES-I), during April and May 1987, was a multi-disciplinary effort aimed at gaining a further understanding of the relationships between productivity and the environment in the vicinity...

  16. Assessment of Off-shore Wind Energy Resource in China using QuikSCAT Satellite data and SAR Satellite Images

    DEFF Research Database (Denmark)

    Xiuzhi, Zhang; Yanbo, Shen; Jingwei, Xu

    2010-01-01

    From August 2008 to August 2009, the project ‘Off-Shore Wind Energy Resource Assessment and Feasibility Study of Off-Shore Wind Farm Development in China’ was carried out by China Meteorological Administration (CMA), which was funded by the EU-China Energy and Environment Programme (EEP). As one ...

  17. Economic valuation of the visual externalities of off-shore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Ladenburg, J.; Dubgaard, A.; Martensen, L.; Tranberg, J.

    2005-07-01

    The study is based on a mail survey including 700 households in a national sample, and 350 households in two sub samples in the Horns Rev and Nysted areas. In the choice experiment, four alternative off-shore wind farm distances from the coast were used namely: 8, 12, 18 and 50 km. Based on the respondents' choices between alternative locations of off-shore wind farms their willingness to pay (WTP) for increasing the distance was elicited using three different sub samples for each of the three locations. These sub samples were constructed using the full sample (B-model), a sample containing respondents who were certain in their choice (C-model) and finally a sample containing respondents, who according to a defined set of questions were considered consistent and rational in their choice (R-model). (au)

  18. Impact Assessment of an Off-Shore Wind Park on Sea Ducks

    DEFF Research Database (Denmark)

    Guillemette, M.; Larsen, J. K.; Clausager, I.

    of the study with a marked difference between Tunø Knob and Ringebjerg Sand in the size available. This was associated with a general impoverishment of the whole benthic community. This suggests that the decrease observed in sea duck abundance over the three years was caused by the availability of food supply......As part of the plan of the Danish government to expand off-shore wind energy production, The Ministry of Environment and Energy, in collaboration with ELSAM (an energy consortium), initiated a three-year study of the potential conflict between the Tunø Knob off-shore wind park and aquatic birds...... in 1994-97. Danish coastal waters support very large, internationally important concentrations of moulting, migrating and wintering sea ducks which depend on shallow water areas as major feeding habitats. Denmark is committed, in relation to international conventions and EU directives, to protect...

  19. Stress analysis of partial sphere used for bottom shell of off-shore structure

    International Nuclear Information System (INIS)

    Nishimaki, Ko; Matsumoto, Kohei; Hori, Tohru; Takeshita, Haruyuki; Iwata, Setsuo

    1976-01-01

    In the near future, various huge off-shore structures will be constructed. Concrete shall become a leading material in the structures, owing to its versatile properties. One of the limitations of concrete is its low tensile strength. The problem of low tensile strength of concrete is dealt with in main by two different methods: by applying prestressing and by designing the structural configuration so that no tensile stresses appear. In the paper, the authors discuss the application of partially spherical shell to huge off-shore structures. Structural analysis by using the finite element method were done in order to investigate the feasibility of the structure. The results were arranged as to certain parameters to derive design charts by which the stresses of check points can be presumed. Optimum shape is also discussed. (auth.)

  20. Design and optimization of air bottoming cycles for waste heat recovery in off-shore platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Haglind, Fredrik

    2014-01-01

    This paper aims at comparing two methodologies to design an air bottoming cycle recovering the waste heat from the power generation system on the Draugen off-shore oil and gas platform. Firstly, the design is determined using the theory of the power maximization. Subsequently, the multi-objective......This paper aims at comparing two methodologies to design an air bottoming cycle recovering the waste heat from the power generation system on the Draugen off-shore oil and gas platform. Firstly, the design is determined using the theory of the power maximization. Subsequently, the multi....... Findings indicate that using the power production, the volume of the recuperator and the net present value as objective functions the optimal pressure ratio (2.52) and the exhaust gas temperature (178.8 °C) differ from the values (2.80 and 145.5 °C) calculated using the theory of the power maximization...

  1. Dynamic performance of power generation systems for off-shore oil and gas platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Breuhaus, Peter; Haglind, Fredrik

    2014-01-01

    %) arises on the prediction of the rotational speed of the high pressure shaft, while the largest deviation (average relative error ~20%) occurs in the evaluation of the pressure at the outlet of the low pressure turbine. As waste heat recovery units (e.g. organic Rankine cycles) are likely...... to be implemented in future off-shore platforms, the proposed model may serve in the design phase for a preliminary assessment of the dynamic response of the power generation system and to evaluate if requirements such as minimum and maximum frequency during transient operation and the recovery time are satisfied......On off-shore oil and gas platforms two or more gas turbines typically support the electrical demand on site by operating as a stand-alone (island) power system. As reliability and availability are major concerns during operation, the dynamic performance of the power generation system becomes...

  2. Electrical Structure of Future Off-shore Wind Power Plant with a High Voltage Direct Current Power Transmission

    DEFF Research Database (Denmark)

    Sharma, Ranjan

    The increasing demand of electric power and the growing consciousness towards the changing climate has led to a rapid development of renewable energy in the recent years. Among all, wind energy has been the fastest growing energy source in the last decade. But the growing size of wind power plants......, better wind conditions at off-shore and the general demand to put them out of sight have all contributed to the installation of large wind power plants in off-shore condition. However, moving wind power plants far out in the off-shore comes with many associated problems. One of the main challenges...... is the transmission of power over long distance. Historically, the power transmission from off-shore wind power plants has been done via HVAC submarine cables. This provides a simple solution, but AC cables cannot be arbitrarily long. It is shown in the report that major issues with HVAC cable transmission system...

  3. The healthcare off-shoring industry in developing economies--institutional and economic foundations: an Indian case.

    Science.gov (United States)

    Kshetri, Nir

    2011-01-01

    Industrialized world-based healthcare providers are increasingly off-shoring low-end healthcare services such as medical transcription, billing and insurance claims. High-skill medical jobs such as tele-imaging and tele-pathology are also being sub-contracted to developing countries. Despite its importance, little theory or research exists to explain what factors affect industry growth. The article's goals, therefore, are to examine economic processes associated with developing economies' shift from low- to high-value information technology enabled healthcare services, and to investigate how these differ in terms of legitimacy from regulative, normative and cognitive institutions in the sending country and how healthcare services differ from other services. This research is conceptual and theory-building. Broadly, its approach can be described as a positivistic epistemology. Anti off-shoring regulative, normative and cognitive pressures in the sending country are likely to be stronger in healthcare than in most business process outsourcing. Moreover, such pressures are likely to be stronger in high-value rather than in low-value healthcare off-shoring. The findings also indicate that off-shoring low-value healthcare services and emergent healthcare industries in a developing economy help accumulate implicit and tacit knowledge required for off-shoring high-value healthcare services. The approach lacks primary data and empirical documentation. The article helps in understanding industry drivers and its possible future direction. The findings help in understanding the lens through which various institutional actors in a sending country view healthcare service off-shoring. The article's value stems from its analytical context, mechanisms and processes associated with developing economies' shift to high-value healthcare off-shoring services.

  4. Visual analysis of uncertainties in ocean forecasts for planning and operation of off-shore structures

    KAUST Repository

    Hollt, Thomas; Magdy, Ahmed; Chen, Guoning; Gopalakrishnan, Ganesh; Hoteit, Ibrahim; Hansen, Charles D.; Hadwiger, Markus

    2013-01-01

    We present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations used in ocean forecasting, i.e, simulations of sea surface elevation. Our system enables the interactive planning of both the placement and operation of off-shore structures. We illustrate this using a real-world simulation of the Gulf of Mexico. Off-shore structures, such as those used for oil exploration, are vulnerable to hazards caused by strong loop currents. The oil and gas industry therefore relies on accurate ocean forecasting systems for planning their operations. Nowadays, these forecasts are based on multiple spatio-temporal simulations resulting in multidimensional, multivariate and multivalued data, so-called ensemble data. Changes in sea surface elevation are a good indicator for the movement of loop current eddies, and our visualization approach enables their interactive exploration and analysis. We enable analysis of the spatial domain, for planning the placement of structures, as well as detailed exploration of the temporal evolution at any chosen position, for the prediction of critical ocean states that require the shutdown of rig operations. © 2013 IEEE.

  5. Qualitative and Quantitative Analysis of Off-Shore Wind Energy Project’s Risks

    Directory of Open Access Journals (Sweden)

    Sayed Amir Hamzeh Mirkheshti

    2017-01-01

    Full Text Available The benefits of wind power can solve the issue of growing power consumption with insufficient distribution facilities. Based on an extensive research on more than 20 studies, this study explores the risks associated with off-shore wind energy in Persian Gulf in Iran. This paper tries to identify the risks in related off-shore wind energy project, in order to specify which variables have the most impact on project by qualitative analysis through application of the impact and the possibility of every risk. A survey was conducted in order to determine the relative importance of variables and risks. Certain key components in completion of the project should be taken into account such as technology, research team, expert teams (personnel that have a good knowledge of this industry, and choosing the right spot where the wind farms will be located. The objective of this paper is to present the variables encountered in wind power project and to highlight the risks that must be controlled by the project developers, project team, supply chain actors, manufacturers, and all the stockholders involved in successful completion of a project.

  6. The off-shore Transport of China Coastal Current over Taiwan Bank in Winter

    Science.gov (United States)

    Liao, E.; Yan, X. H.; Oey, L. Y.; Jiang, Y.

    2016-12-01

    In winter, an off-shore flow of China Coastal Current can be inferred from satellite and in-situ data over the Taiwan Bank. The dynamics related to this off-shore flow have not been previously explained and are examined here using observations and model. Influenced by southward wind stress and opposing pressure gradient, currents over the Taiwan Bank can be classified into three regimes. The southward China Coastal Current flows pass the Taiwan Bank when the wind stress is stronger than a critical value which depends on the opposite pressure gradient force. The coastal current turns northward under a weak wind stress. Two opposite currents converge over the bank and a branch of the coastal current then turns into the northward warm current when these two forces are in balance. Analysis of the vorticity balance shows that the cross-isobath movement is related to a negative bottom stress curl over the Taiwan Bank. Both bottom Ekman transport and shear and curvature vorticity related to the weak bottom slope over the Taiwan Bank contribute to the bottom stress curl. Composite analyses using observations tend to support the model results.

  7. Visual analysis of uncertainties in ocean forecasts for planning and operation of off-shore structures

    KAUST Repository

    Hollt, Thomas

    2013-02-01

    We present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations used in ocean forecasting, i.e, simulations of sea surface elevation. Our system enables the interactive planning of both the placement and operation of off-shore structures. We illustrate this using a real-world simulation of the Gulf of Mexico. Off-shore structures, such as those used for oil exploration, are vulnerable to hazards caused by strong loop currents. The oil and gas industry therefore relies on accurate ocean forecasting systems for planning their operations. Nowadays, these forecasts are based on multiple spatio-temporal simulations resulting in multidimensional, multivariate and multivalued data, so-called ensemble data. Changes in sea surface elevation are a good indicator for the movement of loop current eddies, and our visualization approach enables their interactive exploration and analysis. We enable analysis of the spatial domain, for planning the placement of structures, as well as detailed exploration of the temporal evolution at any chosen position, for the prediction of critical ocean states that require the shutdown of rig operations. © 2013 IEEE.

  8. Shore and off-shore monitoring of Rana Pratap Sagar lake

    International Nuclear Information System (INIS)

    Verma, P.C.; Roy, Alpana; Hegde, A.G.

    2005-01-01

    The Rana Pratap Sagar (RPS) is a man made fresh water reservoir on the river Chambal and is located about 65 km away from Kota city in the state of Rajasthan. It is a balancing reservoir between Gandhi Sagar, upstream and Jawahar Sagar, downstream. On the eastern bank of RPS there exist Rajasthan Atomic Power Station (RAPS) Site, comprising of four operating pressurized Heavy Water Reactors (PHWRs) of 220 MWe each. The low level radioactive effluents from RAPS, are released in controlled manner to RPS. On release the effluents undergo dispersion in the aquatic environment of RPS and may reach man through, various pathways. Being fresh water reservoir, considerable emphasis is laid on the aquatic monitoring aspects relating to RPS and downstream reservoirs. This paper presents the monitored levels of radioactivity prevailing in the aquatic samples collected from near shore and off shore locations of RPS. (author)

  9. Design and optimization of air bottoming cycles for waste heat recovery in off-shore platforms

    International Nuclear Information System (INIS)

    Pierobon, Leonardo; Haglind, Fredrik

    2014-01-01

    Highlights: • Theory of power maximization used to design an air bottoming cycle. • Theory of power maximization extended by a multi-objective optimization method. • Three objective functions considered: net power output, recuperator volume and net present value. • Comparison between the theory of power maximization and the multi-objective optimization method. • Case study: a methodology applied to recover exhaust heat on off-shore platforms. - Abstract: This paper aims at comparing two methodologies to design an air bottoming cycle recovering the waste heat from the power generation system on the Draugen off-shore oil and gas platform. Firstly, the design is determined using the theory of the power maximization. Subsequently, the multi-objective optimization approach is employed to maximize the economic revenue, the compactness and the power production of the air bottoming cycle. The system compactness is assessed by introducing a detailed model of the shell and tube recuperator and including geometric quantities in the set of optimization variables. Findings indicate that using the power production, the volume of the recuperator and the net present value as objective functions the optimal pressure ratio (2.52) and the exhaust gas temperature (178.8 °C) differ from the values (2.80 and 145.5 °C) calculated using the theory of the power maximization. The highest net present value (2.8 M$) is found for a volume of the recuperator of 128 m 3 . Thus, it can be concluded that the multi-objective optimization approach enables extending the theory of power maximization bridging the gap between a mere optimization of the thermodynamic cycle and the practical feasibility of a power generation system

  10. Database Design for the Evaluation of On-shore and Off-Shore Storm Characteristics over East Central Florida

    Science.gov (United States)

    Simpson, Amy A.; Wilson, Jennifer G.; Brown, Robert G.

    2015-01-01

    Data from multiple sources is needed to investigate lightning characteristics over differing terrain (on-shore vs. off-shore) by comparing natural cloud-to-ground lightning behavior differences depending on the characteristics of attachment mediums. The KSC Lightning Research Database (KLRD) was created to reduce manual data entry time and aid research by combining information from various data sources into a single record for each unique lightning event of interest. The KLRD uses automatic data handling functions to import data from a lightning detection network and identify and record lighting events of interest. Additional automatic functions import data from the NASA Buoy 41009 (located approximately 20 miles off the coast) and the KSC Electric Field Mill network, then match these electric field mill values to the corresponding lightning events. The KLRD calculates distances between each lightning event and the various electric field mills, aids in identifying the location type for each stroke (i.e., on-shore vs. off-shore, etc.), provides statistics on the number of strokes per flash, and produces customizable reports for quick retrieval and logical display of data. Data from February 2014 to date covers 48 unique storm dates with 2295 flashes containing 5700 strokes, of which 2612 are off-shore and 1003 are on-shore. The number of strokes per flash ranges from 1 to 22. The ratio of single to subsequent stroke flashes is 1.29 for off-shore strokes and 2.19 for on-shore strokes.

  11. Impact assessment of an off-shore wind park on sea ducks

    International Nuclear Information System (INIS)

    Guillemette, M.; Kyed Larsen, J.; Clausager, I.

    1998-03-01

    As part of the plan of the Danish government to expand off-shore wind energy production, The Ministry of Environment and Energy, in collaboration with ELSAM (an energy consortium), initiated a three-year study of the potential conflict between the Tunoe Knob off-shore wind park and aquatic birds in 1994-97. Danish coastal waters support very large, internationally important concentrations of moulting, migrating and wintering sea ducks which depend on shallow water areas as major feeding habitats. Denmark is committed, in relation to international conventions and EU directives, to protect and maintain these populations of aquatic birds and such shallow coastal areas are precisely the type of areas in which future wind parks are planned. Two general approaches were adopted for the investigation: the before-after-control-impact design (BACI) and After studies conducted around the wind park. The aim of the BACI studies was to compare bird abundance and distribution before and after the construction of the wind park and between the area presumably affected by the development and a control area. This was carried out on three spatial scales: (i) conducting aerial surveys in two large zones (about 5,000 ha), Tunoe Knob and Ringebjerg Sand, while controlling the total number of birds in Aarhus Bay (88,000 ha), (ii) conducting ground surveys of two areas of about 700-800 ha coverage at Tunoe Knob and Ringebjerg Sand, using the latter as a control area and (iii) within Tunoe using three sub areas (160-250 ha) as controls compared to the construction area. The after experiments were conducted around the wind park with the aim of controlling the confounding effect of food supply and to establish (a) the short-term possible effects of noise and rotor movements generated by the turbines on the distribution and abundance of sea ducks and (b) the long-term scaring effect of the wind park (the impact of revolving rotors and the presence of the standing towers). Finally, an

  12. The ARGO Project: assessing NA-TECH risks on off-shore oil platforms

    Science.gov (United States)

    Capuano, Paolo; Basco, Anna; Di Ruocco, Angela; Esposito, Simona; Fusco, Giannetta; Garcia-Aristizabal, Alexander; Mercogliano, Paola; Salzano, Ernesto; Solaro, Giuseppe; Teofilo, Gianvito; Scandone, Paolo; Gasparini, Paolo

    2017-04-01

    ARGO (Analysis of natural and anthropogenic risks on off-shore oil platforms) is a 2 years project, funded by the DGS-UNMIG (Directorate General for Safety of Mining and Energy Activities - National Mining Office for Hydrocarbons and Georesources) of Italian Ministry of Economic Development. The project, coordinated by AMRA (Center for the Analysis and Monitoring of Environmental Risk), aims at providing technical support for the analysis of natural and anthropogenic risks on offshore oil platforms. In order to achieve this challenging objective, ARGO brings together climate experts, risk management experts, seismologists, geologists, chemical engineers, earth and coastal observation experts. ARGO has developed methodologies for the probabilistic analysis of industrial accidents triggered by natural events (NA-TECH) on offshore oil platforms in the Italian seas, including extreme events related to climate changes. Furthermore the environmental effect of offshore activities has been investigated, including: changes on seismicity and on the evolution of coastal areas close to offshore platforms. Then a probabilistic multi-risk framework has been developed for the analysis of NA-TECH events on offshore installations for hydrocarbon extraction.

  13. Dynamic performance of a combined gas turbine and air bottoming cycle plant for off-shore applications

    DEFF Research Database (Denmark)

    Benato, Alberto; Pierobon, Leonardo; Haglind, Fredrik

    2014-01-01

    and a combined gas turbine coupled with an air bottoming cycle plant. The case study is the Draugen off-shore oil and gas platform, located in the North Sea, Norway. The normal electricity demand is 19 MW, currently covered by two gas turbines generating each 50% of the power demand, while the third turbine......When the Norwegian government introduced the CO2 tax for hydrocarbon fuels, the challenge became to improve the performance of off-shore power systems. An oil and gas platform typically operates on an island (stand-alone system) and the power demand is covered by two or more gas turbines. In order...... to improve the plant performance, a bottoming cycle unit can be added to the gas turbine topping module, thus constituting a combined cycle plant. This paper aims at developing and testing the numerical model simulating the part-load and dynamic behavior of a novel power system, composed of two gas turbines...

  14. Canopy interactions of rainfall in an off-shore mangrove ecosystem dominated by Rhizophora mangle (Belize)

    Science.gov (United States)

    Wanek, Wolfgang; Hofmann, Julia; Feller, Ilka C.

    2007-10-01

    SummaryBulk precipitation, throughfall and stemflow were collected to study anthropogenic effects on above-ground nutrient cycling in an off-shore mangrove forest ( Rhizophora mangle L.) on Twin Cays, Belize. Samples were collected in a nitrogen limited fringe and phosphorus limited dwarf zone, and from an adjacent nitrogen fertilized fringe and a phosphorus fertilized dwarf zone. Inorganic cations and anions, dissolved organic carbon (DOC) and nitrogen (DON) were analysed. Throughfall represented 84% of precipitation volume. Sea salt ions (Cl -, Na +, SO42- and Mg 2+) and DOC accounted for the highest proportion of solutes in rainwater, throughfall and stemflow in R. mangle stands. Non-marine sources dominated the flux of DON, DOC, NO3-, NH4+, and inorganic P (P i) in bulk precipitation and throughfall and partially contributed to Ca 2+ and K +. Deposition ratios (throughfall deposition:bulk deposition) showed that inorganic NH4+, and less so P i were retained in the canopy of R. mangle from throughfall while all other solutes increased. Canopy leaching contributed in increasing order to net throughfall of Ca 2+, Cl -, SO42-/K, Mg 2+ and Na + but dry deposition dominated the net throughfall flux during the investigated period. Fertilizer treatment and zone did only slightly affect solute concentrations of hot-water extracts of leaves, of throughfall and stemflow in stands of similar stature. While litterfall and primary production have previously been shown to increase substantially upon nutrient enrichment of mangroves we therefore conclude that fertilization, as a surrogate of anthropogenic eutrophication, may not increase nutrient leaching from mangrove canopies, and thus may only have a minor effect on soluble organic matter cycling and inputs into mangrove food webs.

  15. Effects on harbour porpoises from Roedsand 2 Off-shore Wind Farm

    Energy Technology Data Exchange (ETDEWEB)

    Teilmann, J.; Tougaard, J.; Carstensen, J.

    2012-11-15

    E.ON Vind Sverige has been commissioned the construction of Roedsand 2 Offshore Wind Farm comprising 90 wind turbines, south of Lolland-Falster, Denmark. The location of the wind farm is 3 km west of the existing Nysted Offshore Wind Farm with 72 turbines. In combination the two wind farms represents the largest wind farm area in the world. Porpoises were monitored by automatic acoustic dataloggers (T-PODs) according to a statistical BACI design and deployed during baseline (Sep 2008-Feb 2009) and during operation (Sep 2011-Mar 2012). These instruments were deployed at 10 stations covering a coastal stretch of 35 km from Gedser to Roedby, including the wind farm area with reference areas on both sides. In addition, background noise at four of the T-POD stations was recorded by automatic noise loggers. In order to assess the potential cumulative effect of two adjacent wind farms, similar data from the Nysted Offshore Wind Farm were also analysed. We found no overall change in echolocation activity over the entire monitoring area from baseline to operation of Roedsand 2 Offshore Wind Farm. Also, there was no significant change in the echolocation activity in Roedsand 2 Offshore Wind Farm relative to each or a combination of the three reference areas, i.e. changes from baseline to operation were similar in the impact and reference areas. Also no significant change in noise levels audible to porpoises was found. This could be due to a generally high noise level in the area, masking the turbine noise or that the noise loggers in the wind farm were deployed between the wind turbines, i.e. at distances {approx}350-450 m from the turbines. This study also shows that the echolocation activity is still significantly lower in Nysted Offshore Wind Farm since the baseline in 2001-2002, although the difference seem to gradually diminish possibly due to a habituation of the porpoises to the wind farm or better feeding posibilities. We found no cumulative effect of the two wind

  16. Large-scale integration of off-shore wind power and regulation strategies of cogeneration plants in the Danish electricity system

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2005-01-01

    The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply......The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply...

  17. Power-hardware-in-the-loop test of VSC-HVDC connection for off-shore wind power plants

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ranjan [Siemens Wind Power A/S, Brande (Denmark); Technical Univ. of Denmark (Denmark). Center for Electric Technology; Cha, Seung T.; Wu, Qiuwei; Rasmussen, Tonny W.; Oestergaard, Jacob [Technical Univ. of Denmark (Denmark). Center for Electric Technology; Jensen, Kim H. [Siemens Wind Power A/S, Brande (Denmark)

    2011-07-01

    This paper present a power-hardware-in-the-loop (PHIL) test of an off-shore wind power plant (WPP) interconnected to the on-shore grid via a VSC-HVDC connection. The intention of the PHIL test is to verify the hardware interaction and the control co-ordination between the plant side VSC of the HVDC system and the wind turbines within the WPP in order to ensure smooth operation of the WPP under both normal and fault operating condition. The PHIL test platform is comprised of a real time digital simulator (RTDS), a Spitzenberger Spies three phase 7,5 kW power amplifier, a purpose built VSC and a DC chopper. The WPP is simulated in the RTDS as a single full-scale wind turbine. The simulated WPP interacts with the WPP side VSC through the power amplifier. The interface between the RTDS and the power amplifier is done via an analogue GTAO I/O card of the RTDS and the input channel of the amplifier. The amplifier scales up the voltages at the point of connection of the WPP in the RTDS to the voltage level for the WPP side VSC. The WPP side VSC converter is equipped with a DC chopper. The test results show the successful control coordination between the WPP and the plant side VSC converter of the HVDC connection of the WPP. (orig.)

  18. Off-Shore wind potential estimation along the coast of Chile by using scatterometer and Reanalysis data

    Directory of Open Access Journals (Sweden)

    C. Mattar

    2014-06-01

    Full Text Available This work presents the first offshore wind potential estimation over the coast of Chile using long term data series from “QuikSCAT (V04 wind vectors” and ERA-interim’s wind product between 1999-2009 and 1979-2012, respectively. Weibull and Rayleigh’s distribution were used to adjust the data series from the study period to find the probability density function, mean wind speed, maximum and minimum from each data series adjusted per pixel. Power generation and a capacity factor were estimated for the whole scene using three wind turbine models corresponding to 3.6, 5.0 and 8.0 MW. The images obtained from the data processing were grouped into three different wind power zones named (A located up north, (B in the center and (C down south-center. The mean capacity factors are higher than 20%, moreover B and C areas have an average of 36%. This work shows the high wind power potential to generate electricity by using wind off-shore technologies along the coast of Chile.

  19. Sound Propagation Around Off-Shore Wind Turbines. Long-Range Parabolic Equation Calculations for Baltic Sea Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Lisa

    2003-07-01

    Low-frequency, long-range sound propagation over a sea surface has been calculated using a wide-angel Cranck-Nicholson Parabolic Equation method. The model is developed to investigate noise from off-shore wind turbines. The calculations are made using normal meteorological conditions of the Baltic Sea. Special consideration has been made to a wind phenomenon called low level jet with strong winds on rather low altitude. The effects of water waves on sound propagation have been incorporated in the ground boundary condition using a boss model. This way of including roughness in sound propagation models is valid for water wave heights that are small compared to the wave length of the sound. Nevertheless, since only low frequency sound is considered, waves up to the mean wave height of the Baltic Sea can be included in this manner. The calculation model has been tested against benchmark cases and agrees well with measurements. The calculations show that channelling of sound occurs at downwind conditions and that the sound propagation tends towards cylindrical spreading. The effects of the water waves are found to be fairly small.

  20. Echolocation in small cetaceans

    DEFF Research Database (Denmark)

    Ladegaard, Michael

    2017-01-01

    Many animals exploit sound for navigational purposes, but only some produce signals dedicated to probe their environment actively through echolocation. Only in bats and toothed whales has echolocation evolved to serve as a primary sense informing not only navigation, but also foraging on highly...... a directional, short-range biosonar operated at very high update rates compared to marine toothed whales (Chapter 2). I further studied how these river dolphins adjust their biosonar as they close in on and intercept prey in the first study to measure on-axis source parameters on wild toothed whales during prey...

  1. Shallow Off-Shore Archaeological Prospection with 3-D Electrical Resistivity Tomography: The Case of Olous (Modern Elounda, Greece

    Directory of Open Access Journals (Sweden)

    Kleanthis Simyrdanis

    2016-10-01

    Full Text Available It is well known that nowadays as well as in the past the vast majority of human habitation and activities are mainly concentrated in littoral areas. Thus the increased attention to coastal zone management contributed to the development and implementation of shallow-water mapping approaches for capturing current environmental conditions. During the last decade, geophysical imaging techniques like electrical resistivity tomography (ERT have been used in mapping onshore buried antiquities in a non-destructive manner, contributing to cultural heritage management. Despite its increased implementation in mapping on-shore buried archaeological remains, ERT has minimal to non-existent employment for the understanding of the past dynamics in littoral and shallow off-shore marine environments. This work presents the results of an extensive ERT survey in investigating part of the Hellenistic to Byzantine submerged archaeological site of Olous, located on the north-eastern coast of Crete, Greece. A marine area of 7100 m2 was covered with 178 densely spaced ERT lines having a cumulative length of 8.3 km. A combination of submerged static and moving survey modes were used to document potential buried and submerged structures. The acquired data from the marine environment were processed with two-dimensional and three-dimensional inversion algorithms. A real time kinematic global navigation satellite system was used to map the visible submerged walls and compile the bathymetry model of the bay. The adaptation of ERT in reconstructing the underwater archaeological remains in a shallow marine environment presented specific methodological and processing challenges. The in situ experience from the archaeological site of Olous showed that ERT provided a robust method for mapping the submerged archaeological structures related to the ancient built environment (walls, buildings, roads, signifying at the same time the vertical stratigraphy of the submerged sediments

  2. Artificial marine habitats favour a single fish species on a long-term scale: the dominance of Boops boops around off-shore fish cages

    Directory of Open Access Journals (Sweden)

    Rodrigo Riera

    2014-12-01

    Full Text Available Off-shore fish cages are new artificial habitats that can affect pelagic fish assemblages and constitute an important food source for wild fish assemblages. This aggregation has noticeable ecological consequences in cage areas in impoverished ecosystems such as those in the Canary archipelago (NE Atlantic Ocean. However, this new habitat could be dominated by a single species, reducing its positive ecological effects. Wild fish assemblages associated with an off-shore fish lease on the northeastern coast of Tenerife (Canary Islands were sampled for six years. Fish assemblage structure beneath fish cages and at controls ( > 500 m from cages differed significantly between locations, with 13 times greater abundance at cage locations. These differences were mainly explained by the dominance of bogue (Boops boops around fish cages. This trend was consistent in the long-term throughout the study period (2004-2009, affecting local fisheries. The presence of fish cages significantly altered wild fish assemblages in the study area, enhancing mainly biomass and abundance of one species, bogue, and causing shifts in species composition.

  3. Echolocation in Oilbirds and swiftlets

    Directory of Open Access Journals (Sweden)

    Signe eBrinkløv

    2013-05-01

    Full Text Available The discovery of ultrasonic bat echolocation prompted a wide search for other animal biosonar systems, which yielded, among few others, two avian groups. One, the South American Oilbird (Steatornis caripensis: Caprimulgiformes, is nocturnal and eats fruit. The other is a selection of diurnal, insect-eating swiftlets (species in the genera Aerodramus and Collocalia: Apodidae from across the Indo-Pacific. Bird echolocation is restricted to lower frequencies audible to humans, implying a system of poorer resolution than the ultrasonic (>20 kHz biosonar of most bats and toothed whales. As such, bird echolocation has been labelled crude or rudimentary. Yet, echolocation is found in at least 16 extant bird species and has evolved several times in avian lineages. Birds use their syringes to produce broadband click-type biosonar signals that allow them to nest in dark caves and tunnels, probably with less predation pressure. There are ongoing discrepancies about several details of bird echolocation, from signal design to the question about whether echolocation is used during foraging. It remains to be seen if bird echolocation is as sophisticated as that of tongue-clicking rousette bats. Bird echolocation performance appears to be superior to that of blind humans using signals of notable similarity. However, no apparent specializations have been found so far in the birds' auditory system (from middle ear to higher processing centres. The advent of light-weight recording equipment and custom software for examining signals and reconstructing flight paths now provides the potential to study the echolocation behaviour of birds in more detail and resolve such issues.

  4. Specifications for offshore pipeline - an analysis of installers needs versus manufacturers capabilities; Especificacoes para tubulacoes off-shore - uma analise das necessidades do instalador versus capacidade dos fabricantes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Mauricio; Godoy, Mauricio; Ferreira; Sergio; Kojima, Sergio

    2003-07-01

    The development of off-shore gas fields on the last years led to a sophistication on the methods of laying the pipes. This consequently led to specifications more and more stringent on the characteristics of the pipes that may interfere with the weld in barges or ships, notoriously when using automatic girth welding. The main restrictions are on pipe length, and dimensional characteristics such as: straightness; out of roundness; weld off-set, as well as chemistry. To cope with this trend the pipe mills had to make new developments and investments, and the cost of production of the pipes increased. Considering the real needs of the final customer, we concluded that some requirements are too stringent, leading to a final increase of the final cost of the installed pipeline, as some requirements that apparently save some installation costs, are difficult to be obtained during pipe fabrication, and cause increase on the final cost of it. This paper was made considering UOE/Three bend roll-SAW pipes, diameter 24'' and bigger. (author)

  5. The fatigue and corrosion fatigue behavior of welded Inconel 625 alloy employed in off-shore platforms; Avaliacao do comportamento a fadiga e a corrosao-fadiga de juntas soldadas da liga Inconel 625 testada para uso em plaaformas off-shore

    Energy Technology Data Exchange (ETDEWEB)

    Pfingstag, M.E.; Schroeder, R.M.; Mueller, I.L. [Universidade Federal do Rio Grande do Sul (LAPEC/UFRGS), Porto Alegre, RS (Brazil). Dept. de Metalurgia. Lab. de Pesquisa em Corrosao], e-mail: maiquel10@walla.com

    2006-07-01

    The fatigue and corrosion fatigue behavior of welded Inconel 625 employed live like risers in off-shore platforms was studied. These risers may be employed integrally of this alloy, or combined with API 52 X60 steel in the form of 'Clads'. One of the most susceptible points in .these structures is the circumferential weld that joint the pipes together. In these regions, stresses and defects are generated by the welding process, and these material remind in contact with aggressive species like, chlorides and Co{sub 2} . Polarization curves, slow strain rate fatigue and corrosion fatigue tests were used to characterize the Inconel alloy behavior. In the welded deposit condition, this alloy shows an excellent resistance corrosion and a good fatigue and corrosion-fatigue behavior.(author)

  6. Off shore wind power plants

    International Nuclear Information System (INIS)

    Bettinali, F.; Botta, G.; Lembo, E.; Serri, L.; Vailati, R.; Viani, S.

    2008-01-01

    In Italy are present sea area with good wind intensity usable for offshore wind farms. The tourist vocation of territory requires facilities to accept the people at sufficient distance from the coast in deep waters. Innovative solution on the floating platforms can be an interesting prospect [it

  7. Metodologie innovative per il supporto alla progettazione e all’analisi delle prestazioni di impianti ad energia solare a concentrazione ed eolici off-shore utilizzando immagini satellitari ottiche e SAR

    OpenAIRE

    Morelli, Marco; Masini, Andrea; Alberto, Marco; Potenza, Marco Alberto Carlo

    2014-01-01

    In questo lavoro presentiamo delle nuove metodologie, sviluppate nell’ambito del progetto SATENERG (Servizi sATellitari per le ENergie Rinnovabili di nuova Generazione) finanziato dall’Agenzia Spaziale Italiana, sia per il supporto alla progettazione/pianificazione che per il monitoraggio quasi in tempo reale e l’analisi delle prestazioni degli impianti ad energia rinnovabile di nuova generazione (CSP, CPV ed eolici off-shore) utilizzando immagini satellitari. In particolare pe...

  8. Inconspicuous echolocation in hoary bats (Lasiurus cinereus).

    Science.gov (United States)

    Corcoran, Aaron J; Weller, Theodore J

    2018-05-16

    Echolocation allows bats to occupy diverse nocturnal niches. Bats almost always use echolocation, even when other sensory stimuli are available to guide navigation. Here, using arrays of calibrated infrared cameras and ultrasonic microphones, we demonstrate that hoary bats ( Lasiurus cinereus ) use previously unknown echolocation behaviours that challenge our current understanding of echolocation. We describe a novel call type ('micro' calls) that has three orders of magnitude less sound energy than other bat calls used in open habitats. We also document bats flying close to microphones (less than 3 m) without producing detectable echolocation calls. Acoustic modelling indicates that bats are not producing calls that exceed 70-75 dB at 0.1 m, a level that would have little or no known use for a bat flying in the open at speeds exceeding 7 m s -1 This indicates that hoary bats sometimes fly without echolocation. We speculate that bats reduce echolocation output to avoid eavesdropping by conspecifics during the mating season. These findings might partly explain why tens of thousands of hoary bats are killed by wind turbines each year. They also challenge the long-standing assumption that bats-model organisms for sensory specialization-are reliant on sonar for nocturnal navigation. © 2018 The Author(s).

  9. Intensity and directionality of bat echolocation signals

    DEFF Research Database (Denmark)

    Jakobsen, Lasse; Brinkløv, Signe; Surlykke, Annemarie

    2013-01-01

    will increase signal directionality in the field along with intensity thus increasing sonar range. During the last phase of prey pursuit, vespertilionid bats broaden their echolocation beam considerably, probably to counter evasive maneuvers of eared prey. We highlight how multiple call parameters (frequency......The paper reviews current knowledge of intensity and directionality of bat echolocation signals. Recent studies have revealed that echolocating bats can be much louder than previously believed. Bats previously dubbed "whispering" can emit calls with source levels up to 110 dB SPL at 10 cm......, duration, intensity, and directionality of echolocation signals) in unison define the search volume probed by bats and in turn how bats perceive their surroundings. Small changes to individual parameters can, in combination, drastically change the bat's perception, facilitating successful navigation...

  10. Echolocation

    Indian Academy of Sciences (India)

    the behaviour of bats for almost two decades. His ... even deep into underground caves in which there is absolutely no light. ... on the situation and gather detailed information on their flight path. .... addition to these changes, a qualitative change in the pulse pattern also occurs .... The processing includes information such as.

  11. Mechanisms of echolocation in bats; Komori no echolocation

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, M.

    1999-12-05

    This paper summarizes echolocation in bats. Bats hear reflected echo of ultrasonic waves they generate themselves, enabling them to fly freely in darkness or catch preys. Bats generate wave sounds of large volume at high frequencies suitable for catching preys, and can detect distance from objects, shapes of the objects, and relative velocity with that of the preys. Considering in terms of physics, bats detect the distance from delay in echo reflection, the size from echo intensity, and the relative velocity from the Doppler effect. The static sound generated ten times per second contains CF sound (for detecting a target) and FM sound (for measuring the distance), each composed of four frequency components. The animal's brain unifies and calculates signals from hair cells in the cochleae to acquire items of information including distance. Neurons exist in the acoustic sense field in brain cortex to generate impulses only when the static sound is coupled with the echo. Response properties of these neurons are formed in the brain via complex processing based on acoustic information caught by the hair cells. (NEDO)

  12. Echolocation The Strange Ways of Bats

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 5. Echolocation The Strange Ways of Bats. G Marimuthu. General Article Volume 1 Issue 5 May 1996 pp 40-48. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/05/0040-0048. Author Affiliations.

  13. Unsupervised Learning (Clustering) of Odontocete Echolocation Clicks

    Science.gov (United States)

    2015-09-30

    develop methods for clustering of marine mammal echolocation clicks to learn about species assemblages where little or no prior knowledge exists about... Mexico or the Atlanic. 2 APPROACH Acoustic encounters with odontocetes are detected automatically and noise-corrected cepstral features...Estmation of Marine Mammals Using Passive Acoustic Monitoring (DCLDE). KL divergence maps were created for all known species, but the sperm whale

  14. Biomimetic echolocation with application to radar and sonar sensing

    OpenAIRE

    Baker, C. J.; Smith, G. E.; Balleri, Alessio; Holderied, M.; Griffiths, H. D.

    2014-01-01

    Nature provides a number of examples where acoustic echolocation is the primary sensing modality, the most well-known of these being the bat, whale and dolphin. All demonstrate a remarkable ability to "see with sound". Using echolocation they navigate, locate and capture prey. As species, they have not only survived but have thrived in all their individual environments, often solely reliant on echolocation. All of these creatures are inherently cognitive. They all maintain a perception of the...

  15. Echolocating bats cry out loud to detect their prey

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Kalko, Elisabeth K V

    2008-01-01

    Echolocating bats have successfully exploited a broad range of habitats and prey. Much research has demonstrated how time-frequency structure of echolocation calls of different species is adapted to acoustic constraints of habitats and foraging behaviors. However, the intensity of bat calls has b...

  16. Bats aloft: Variation in echolocation call structure at high altitudes

    Science.gov (United States)

    Bats alter their echolocation calls in response to changes in ecological and behavioral conditions, but little is known about how they adjust their call structure in response to changes in altitude. This study examines altitudinal variation in the echolocation calls of Brazilian free-tailed bats, T...

  17. Marine Mammals: Hearing and Echolocation at Coconut Island

    Science.gov (United States)

    2012-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Marine Mammals: Hearing and Echolocation at Coconut ...REPORT DATE 2012 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Marine Mammals: Hearing and Echolocation at Coconut Island

  18. Evolution of high duty cycle echolocation in bats

    DEFF Research Database (Denmark)

    Fenton, M. B.; Faure, P. A.; Ratcliffe, J. M.

    2012-01-01

    Duty cycle describes the relative 'on time' of a periodic signal. In bats, we argue that high duty cycle (HDC) echolocation was selected for and evolved from low duty cycle (LDC) echolocation because increasing call duty cycle enhanced the ability of echolocating bats to detect, lock onto and track...... relative to background objects and their prey. HDC echolocators are particularly sensitive to amplitude and frequency glints generated by the wings of fluttering insects. We hypothesize that narrowband/CF calls produced at high duty cycle, and combined with neurobiological specializations for processing....... In contrast, bats using HDC echolocation emit long duration, narrowband calls dominated by a single constant frequency (CF) separated by relatively short periods of silence. HDC bats separate pulse and echo in frequency by exploiting information contained in Doppler-shifted echoes arising from their movements...

  19. Report on the wind power development field test project in the off-shore park in Daitocho Town in fiscal 1997. System design; 1997 nendo Daitocho kaiyo koen nado ni okeru furyoku kaihatsu field test jigyo hokokusho. System sekkei

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    This paper reports the wind power development field test project in the off-shore park in Daitocho Town in Shizuoka Prefecture. The annual average wind velocity was 4.2 m/s (at height of 20 m above the ground), where the facility utilization rates for 300 and 500 kW class plants were 15.1 and 16.7%, respectively. Both of the annual average wind velocity and the facility utilization rate do not meet the criteria established by NEDO. Although the location is adjacent to the Natural Park, there is no restricting condition for installation. The substation to which system linkage is to be performed is the Daito substation 3 km north of the planned location. The major load is the Daito Spa in the park facility. Ground bed at depth of 5 m will be used as the windmill foundation supporting bed. There is little electromagnetic wave hazard. The location is 380 m away from the nearest residential house, presenting no windmill noise problem. The amount of power to be generated was assumed 281,000 kWh. Specifications for nine models of 300-kW class windmills that can be introduced into Japan were discussed to select a model. The project cost was calculated to be 128.5 million yen. The construction cost will be 428,000 yen and the power generation cost 38.1 yen/kWh. Its economy is poor when the current unit price for surplus power purchase is considered, but the effect of enlightenment may be expected. (NEDO)

  20. Echolocation in the Risso's dolphin, Grampus griseus

    Science.gov (United States)

    Philips, Jennifer D.; Nachtigall, Paul E.; Au, Whitlow W. L.; Pawloski, Jeffrey L.; Roitblat, Herbert L.

    2003-01-01

    The Risso's dolphin (Grampus griseus) is an exclusively cephalopod-consuming delphinid with a distinctive vertical indentation along its forehead. To investigate whether or not the species echolocates, a female Risso's dolphin was trained to discriminate an aluminum cylinder from a nylon sphere (experiment 1) or an aluminum sphere (experiment 2) while wearing eyecups and free swimming in an open-water pen in Kaneohe Bay, Hawaii. The dolphin completed the task with little difficulty despite being blindfolded. Clicks emitted by the dolphin were acquired at average amplitudes of 192.6 dB re 1 μPa, with estimated sources levels up to 216 dB re 1 μPa-1 m. Clicks were acquired with peak frequencies as high as 104.7 kHz (Mfp=47.9 kHz), center frequencies as high as 85.7 kHz (Mf0=56.5 kHz), 3-dB bandwidths up to 94.1 kHz (MBW=39.7 kHz), and root-mean-square bandwidths up to 32.8 kHz (MRMS=23.3 kHz). Click durations were between 40 and 70 μs. The data establish that the Risso's dolphin echolocates, and that, aside from slightly lower amplitudes and frequencies, the clicks emitted by the dolphin were similar to those emitted by other echolocating odontocetes. The particular acoustic and behavioral findings in the study are discussed with respect to the possible direction of the sonar transmission beam of the species.

  1. Early milestones in the understanding of echolocation in bats.

    Science.gov (United States)

    Grinnell, Alan D

    2018-04-23

    Almost 80 years ago, Griffin and Galambos discovered the phenomenon of echolocation in bats. Since then, the field has grown exponentially as new generations of investigators have joined the chase and technological advances have revolutionized working with ultrasound in the laboratory and in the field. Today our understanding of the diversity of behavioral and neural adaptations for echolocation constitutes one of the paramount triumphs of neuroethology. At the invitation of the editor in chief, I here review some of the important milestones in the discovery and early understanding of echolocation in bats through about the mid-1980s.

  2. New discoveries on the ecology and echolocation of the heart ...

    African Journals Online (AJOL)

    New discoveries on the ecology and echolocation of the heart-nosed bat Cardioderma cor with a ... Open Access DOWNLOAD FULL TEXT ... However, additional genetic data are necessary to resolve the phylogeny of Megadermatidae, ...

  3. Neurophysiological findings relevant to echolocation in marine animals

    Science.gov (United States)

    Bullock, T. H.; Ridgway, S. H.

    1972-01-01

    A review of echolocation mechanisms in marine mammals, chiefly porpoises, is given. Data cover peripheral auditory and central neurophysiological specializations favorable to the analysis of echolocating clicks and their echoes. Conclusions show (1) signals are received from 50 up to at least 135 kHz, (2) sound is received through the mandible skin, and (3) the midbrain sites are insensitive to low frequencies (below 6 kHz).

  4. Accelerated FoxP2 evolution in echolocating bats.

    Directory of Open Access Journals (Sweden)

    Gang Li

    Full Text Available FOXP2 is a transcription factor implicated in the development and neural control of orofacial coordination, particularly with respect to vocalisation. Observations that orthologues show almost no variation across vertebrates yet differ by two amino acids between humans and chimpanzees have led to speculation that recent evolutionary changes might relate to the emergence of language. Echolocating bats face especially challenging sensorimotor demands, using vocal signals for orientation and often for prey capture. To determine whether mutations in the FoxP2 gene could be associated with echolocation, we sequenced FoxP2 from echolocating and non-echolocating bats as well as a range of other mammal species. We found that contrary to previous reports, FoxP2 is not highly conserved across all nonhuman mammals but is extremely diverse in echolocating bats. We detected divergent selection (a change in selective pressure at FoxP2 between bats with contrasting sonar systems, suggesting the intriguing possibility of a role for FoxP2 in the evolution and development of echolocation. We speculate that observed accelerated evolution of FoxP2 in bats supports a previously proposed function in sensorimotor coordination.

  5. Bottlenose dolphins perceive object features through echolocation.

    Science.gov (United States)

    Harley, Heidi E; Putman, Erika A; Roitblat, Herbert L

    2003-08-07

    How organisms (including people) recognize distant objects is a fundamental question. The correspondence between object characteristics (distal stimuli), like visual shape, and sensory characteristics (proximal stimuli), like retinal projection, is ambiguous. The view that sensory systems are 'designed' to 'pick up' ecologically useful information is vague about how such mechanisms might work. In echolocating dolphins, which are studied as models for object recognition sonar systems, the correspondence between echo characteristics and object characteristics is less clear. Many cognitive scientists assume that object characteristics are extracted from proximal stimuli, but evidence for this remains ambiguous. For example, a dolphin may store 'sound templates' in its brain and identify whole objects by listening for a particular sound. Alternatively, a dolphin's brain may contain algorithms, derived through natural endowments or experience or both, which allow it to identify object characteristics based on sounds. The standard method used to address this question in many species is indirect and has led to equivocal results with dolphins. Here we outline an appropriate method and test it to show that dolphins extract object characteristics directly from echoes.

  6. Matching-to-sample by an echolocating dolphin (Tursiops truncatus).

    Science.gov (United States)

    Roitblat, H L; Penner, R H; Nachtigall, P E

    1990-01-01

    An adult male dolphin was trained to perform a three-alternative delayed matching-to-sample task while wearing eyecups to occlude its vision. Sample and comparison stimuli consisted of a small and a large PVC plastic tube, a water-filled stainless steel sphere, and a solid aluminum cone. Stimuli were presented under water and the dolphin was allowed to identify the stimuli through echolocation. The echolocation clicks emitted by the dolphin to each sample and each comparison stimulus were recorded and analyzed. Over 48 sessions of testing, choice accuracy averaged 94.5% correct. This high level of accuracy was apparently achieved by varying the number of echolocation clicks emitted to various stimuli. Performance appeared to reflect a preexperimental stereotyped search pattern that dictated the order in which comparison items were examined and a complex sequential-sampling decision process. A model for the dolphin's decision-making processes is described.

  7. Prestin shows divergent evolution between constant frequency echolocating bats.

    Science.gov (United States)

    Shen, Bin; Avila-Flores, Rafael; Liu, Yang; Rossiter, Stephen J; Zhang, Shuyi

    2011-10-01

    The gene Prestin encodes a motor protein that is thought to confer the high-frequency sensitivity and selectivity that characterizes the mammalian auditory system. Recent research shows that the Prestin gene has undergone a burst of positive selection on the ancestral branch of the Old World horseshoe and leaf-nosed bats (Rhinolophidae and Hipposideridae, respectively), and also on the branch leading to echolocating cetaceans. Moreover, these two groups share a large number of convergent amino acid sequence replacements. Horseshoe and leaf-nosed bats exhibit narrowband echolocation, in which the emitted calls are based on the second harmonic of a predominantly constant frequency (CF) component, the frequency of which is also over-represented in the cochlea. This highly specialized form of echolocation has also evolved independently in the neotropical Parnell's mustached bat (Pteronotus parnellii). To test whether the convergent evolution of CF echolocation between lineages has arisen from common changes in the Prestin gene, we sequenced the Prestin coding region (~2,212 bp, >99% coverage) in P. parnellii and several related species that use broadband echolocation calls. Our reconstructed Prestin gene tree and amino acid tree showed that P. parnellii did not group together with Old World horseshoe and leaf-nosed bats, but rather clustered within its true sister species. Comparisons of sequences confirmed that P. parnellii shared most amino acid changes with its congeners, and we found no evidence of positive selection in the branch leading to the genus of Pteronotus. Our result suggests that the adaptive changes seen in Prestin in horseshoe and leaf-nosed bats are not necessary for CF echolocation in P. parnellii.

  8. Prenatal development supports a single origin of laryngeal echolocation in bats.

    Science.gov (United States)

    Wang, Zhe; Zhu, Tengteng; Xue, Huiling; Fang, Na; Zhang, Junpeng; Zhang, Libiao; Pang, Jian; Teeling, Emma C; Zhang, Shuyi

    2017-01-09

    Bat laryngeal echolocation is considered as one of the most complex and diverse modes of auditory sensory perception in animals and its evolutionary history has been the cause of many scientific controversies in the past two decades. To date, the majority of scientific evidence supports that bats (Chiroptera) are divided into two subordinal groups: Yinpterochiroptera, containing the laryngeal echolocating superfamily Rhinolophidae as sister taxa to the non-laryngeal echolocating family Pteropodidae; and Yangochiroptera, containing all other laryngeal echolocating lineages. This topology has led to an unanswered question in mammalian biology: was laryngeal echolocation lost in the ancestral pteropodids or gained convergently in the echolocating bat lineages? To date, there is insufficient and conflicting evidence from fossil, genomic, morphological and phylogenomic data to resolve this question. We detail an ontogenetic study of fetal cochlear development from seven species of bats and five outgroup mammals and show that in early fetal development, all bats including the non-laryngeal echolocating pteropodids have a similarly large cochlea typically associated with laryngeal echolocation abilities. The subsequent cochlear growth rate in the pteropodids is the slowest of all mammals and leads to the pteropodids and the non-echolocating lineages eventually sharing a similar cochlear morphospace as adults. The results suggest that pteropodids maintain a vestigial developmental stage indicative of past echolocation capabilities and thus support a single origin of laryngeal echolocation in bats.

  9. Probing the natural scene by echolocation in bats

    DEFF Research Database (Denmark)

    Moss, Cynthia F; Surlykke, Annemarie

    2010-01-01

    -motor behaviors and flight path control, which draw upon 3-D spatial perception, attention, and memory. This article reviews field and laboratory studies that document adaptive sonar behaviors of echolocating bats, and point to the fundamental signal parameters they use to track and sort auditory objects......Bats echolocating in the natural environment face the formidable task of sorting signals from multiple auditory objects, echoes from obstacles, prey, and the calls of conspecifics. Successful orientation in a complex environment depends on auditory information processing, along with adaptive vocal...

  10. Convergent acoustic field of view in echolocating bats

    DEFF Research Database (Denmark)

    Jakobsen, Lasse; Ratcliffe, John M; Surlykke, Annemarie

    2013-01-01

    Most echolocating bats exhibit a strong correlation between body size and the frequency of maximum energy in their echolocation calls (peak frequency), with smaller species using signals of higher frequency than larger ones. Size-signal allometry or acoustic detection constraints imposed on wavel......Most echolocating bats exhibit a strong correlation between body size and the frequency of maximum energy in their echolocation calls (peak frequency), with smaller species using signals of higher frequency than larger ones. Size-signal allometry or acoustic detection constraints imposed...... on wavelength by preferred prey size have been used to explain this relationship. Here we propose the hypothesis that smaller bats emit higher frequencies to achieve directional sonar beams, and that variable beam width is critical for bats. Shorter wavelengths relative to the size of the emitter translate...... into more directional sound beams. Therefore, bats that emit their calls through their mouths should show a relationship between mouth size and wavelength, driving smaller bats to signals of higher frequency. We found that in a flight room mimicking a closed habitat, six aerial hawking vespertilionid...

  11. Echolocation caBs of twenty southern African bat species

    African Journals Online (AJOL)

    all species, and added that intensity and harmonic information. (not available through ANABAT recordings) would have proved useful for identification. The aim of this study is to present new echolocation data for. 20 southern African species using a time-expansion Petters- son D980 bat detector, particularly with the view to ...

  12. Auditory opportunity and visual constraint enabled the evolution of echolocation in bats.

    Science.gov (United States)

    Thiagavel, Jeneni; Cechetto, Clément; Santana, Sharlene E; Jakobsen, Lasse; Warrant, Eric J; Ratcliffe, John M

    2018-01-08

    Substantial evidence now supports the hypothesis that the common ancestor of bats was nocturnal and capable of both powered flight and laryngeal echolocation. This scenario entails a parallel sensory and biomechanical transition from a nonvolant, vision-reliant mammal to one capable of sonar and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation. Further, we find that among extant predatory bats (all of which use laryngeal echolocation), those with putatively less sophisticated biosonar have relatively larger eyes than do more sophisticated echolocators. We contend that signs of ancient trade-offs between vision and echolocation persist today, and that non-echolocating, phytophagous pteropodid bats may retain some of the necessary foundations for biosonar.

  13. High duty cycle to low duty cycle: echolocation behaviour of the hipposiderid bat Coelops frithii.

    Science.gov (United States)

    Ho, Ying-Yi; Fang, Yin-Ping; Chou, Cheng-Han; Cheng, Hsi-Chi; Chang, Hsueh-Wen

    2013-01-01

    Laryngeally echolocating bats avoid self-deafening (forward masking) by separating pulse and echo either in time using low duty cycle (LDC) echolocation, or in frequency using high duty cycle (HDC) echolocation. HDC echolocators are specialized to detect fluttering targets in cluttered environments. HDC echolocation is found only in the families Rhinolophidae and Hipposideridae in the Old World and in the New World mormoopid, Pteronotus parnellii. Here we report that the hipposiderid Coelops frithii, ostensibly an HDC bat, consistently uses an LDC echolocation strategy whether roosting, flying, or approaching a fluttering target rotating at 50 to 80 Hz. We recorded the echolocation calls of free-flying C. frithii in the field in various situations, including presenting bats with a mechanical fluttering target. The echolocation calls of C. frithii consisted of an initial narrowband component (0.5±0.3 ms, 90.6±2.0 kHz) followed immediately by a frequency modulated (FM) sweep (194 to 113 kHz). This species emitted echolocation calls at duty cycles averaging 7.7±2.8% (n = 87 sequences). Coelops frithii approached fluttering targets more frequently than did LDC bats (C.frithii, approach frequency  = 40.4%, n = 80; Myotis spp., approach frequency  = 0%, n = 13), and at the same frequency as sympatrically feeding HDC species (Hipposideros armiger, approach rate  = 53.3%, n = 15; Rhinolophus monoceros, approach rate  = 56.7%, n = 97). We propose that the LDC echolocation strategy used by C. frithii is derived from HDC ancestors, that this species adjusts the harmonic contents of its echolocation calls, and that it may use both the narrowband component and the FM sweep of echolocations calls to detect fluttering targets.

  14. High duty cycle to low duty cycle: echolocation behaviour of the hipposiderid bat Coelops frithii.

    Directory of Open Access Journals (Sweden)

    Ying-Yi Ho

    Full Text Available Laryngeally echolocating bats avoid self-deafening (forward masking by separating pulse and echo either in time using low duty cycle (LDC echolocation, or in frequency using high duty cycle (HDC echolocation. HDC echolocators are specialized to detect fluttering targets in cluttered environments. HDC echolocation is found only in the families Rhinolophidae and Hipposideridae in the Old World and in the New World mormoopid, Pteronotus parnellii. Here we report that the hipposiderid Coelops frithii, ostensibly an HDC bat, consistently uses an LDC echolocation strategy whether roosting, flying, or approaching a fluttering target rotating at 50 to 80 Hz. We recorded the echolocation calls of free-flying C. frithii in the field in various situations, including presenting bats with a mechanical fluttering target. The echolocation calls of C. frithii consisted of an initial narrowband component (0.5±0.3 ms, 90.6±2.0 kHz followed immediately by a frequency modulated (FM sweep (194 to 113 kHz. This species emitted echolocation calls at duty cycles averaging 7.7±2.8% (n = 87 sequences. Coelops frithii approached fluttering targets more frequently than did LDC bats (C.frithii, approach frequency  = 40.4%, n = 80; Myotis spp., approach frequency  = 0%, n = 13, and at the same frequency as sympatrically feeding HDC species (Hipposideros armiger, approach rate  = 53.3%, n = 15; Rhinolophus monoceros, approach rate  = 56.7%, n = 97. We propose that the LDC echolocation strategy used by C. frithii is derived from HDC ancestors, that this species adjusts the harmonic contents of its echolocation calls, and that it may use both the narrowband component and the FM sweep of echolocations calls to detect fluttering targets.

  15. Innate recognition of water bodies in echolocating bats.

    Science.gov (United States)

    Greif, Stefan; Siemers, Björn M

    2010-11-02

    In the course of their lives, most animals must find different specific habitat and microhabitat types for survival and reproduction. Yet, in vertebrates, little is known about the sensory cues that mediate habitat recognition. In free flying bats the echolocation of insect-sized point targets is well understood, whereas how they recognize and classify spatially extended echo targets is currently unknown. In this study, we show how echolocating bats recognize ponds or other water bodies that are crucial for foraging, drinking and orientation. With wild bats of 15 different species (seven genera from three phylogenetically distant, large bat families), we found that bats perceived any extended, echo-acoustically smooth surface to be water, even in the presence of conflicting information from other sensory modalities. In addition, naive juvenile bats that had never before encountered a water body showed spontaneous drinking responses from smooth plates. This provides the first evidence for innate recognition of a habitat cue in a mammal.

  16. Evidence for echolocation in the oldest known bats.

    Science.gov (United States)

    Novacek, M J

    The earliest-known bats are represented by excellent fossil material, including virtually complete skeletons of Icaronycteris index from the early Eocene (50 Myr BP) of western Wyoming and Palaeochiropteryx tupaiodon from the middle Eocene (45 Myr BP) 'Grube Messel' of western Germany. These taxa have been closely allied with Recent Microchiroptera, a suborder of diverse bats noted for their powers of ultrasonic echolocation. A problem with this relationship is the alleged absence in the Eocene forms of specializations in the auditory region and other aspects of the skeletal system. It has been proposed, therefore, that the oldest bats are members of a group more primitive and possibly ancestral to the Microchiroptera and the visually oriented Megachiroptera. Previously undescribed specimens now show, however, that Icaronycteris and Palaeochiropteryx share special basicranial features with microchiropterans which suggest comparable refinement of ultrasonic echolocation. These results support the theory that a sophisticated sonar system was present in the earliest records of microchiropteran history.

  17. Scanning behavior in echolocating common pipistrelle bats (Pipistrellus pipistrellus.

    Directory of Open Access Journals (Sweden)

    Anna-Maria Seibert

    Full Text Available Echolocating bats construct an auditory world sequentially by analyzing successive pulse-echo pairs. Many other mammals rely upon a visual world, acquired by sequential foveal fixations connected by visual gaze saccades. We investigated the scanning behavior of bats and compared it to visual scanning. We assumed that each pulse-echo pair evaluation corresponds to a foveal fixation and that sonar beam movements between pulses can be seen as acoustic gaze saccades. We used a two-dimensional 16 microphone array to determine the sonar beam direction of succeeding pulses and to characterize the three dimensional scanning behavior in the common pipistrelle bat (Pipistrellus pipistrellus flying in the field. We also used variations of signal amplitude of single microphone recordings as indicator for scanning behavior in open space. We analyzed 33 flight sequences containing more than 700 echolocation calls to determine bat positions, source levels, and beam aiming. When searching for prey and orienting in space, bats moved their sonar beam in all directions, often alternately back and forth. They also produced sequences with irregular or no scanning movements. When approaching the array, the scanning movements were much smaller and the beam was moved over the array in small steps. Differences in the scanning pattern at various recording sites indicated that the scanning behavior depended on the echolocation task that was being performed. The scanning angles varied over a wide range and were often larger than the maximum angle measurable by our array. We found that echolocating bats use a "saccade and fixate" strategy similar to vision. Through the use of scanning movements, bats are capable of finding and exploring targets in a wide search cone centered along flight direction.

  18. Identification of sympatric bat species by the echolocation calls

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    One hundred and thirty-eight echolocation calls of 63 free-flying individuals of five bat species (Rhinolophus ferrumequinum,Myotis formosus,Myotis ikonnikovi,Myotis daubentoni and Murina leucogaster)were recorded (by ultrasonic bat detector (D980)) in Zhi'an village of Jilin Province,China.According to the frequency-time spectra,these calls were categorized into two types:FM/CF (constant frequency) / FM (R.ferrumequinum) and FM (frequency modulated)(M.formosus,M.ikonnikovi,M.daubentoni and M.leucogaster).Sonograms of the calls of R.ferrumequinum could easily be distinguished from those of the other four species.For the calls of the remaining four species,six echolocation call parameters,including starting frequency,ending frequency,peak frequency duration,longest inter-pulse interval and shortest inter-pulse interval,were examined by stepwise discriminant analysis.The results show that 84.1% of calls were correctly classified,which indicates that these parameters of echolocation calls play an important role in identifying bat species.These parameters can be used to test the accuracy of general predictions based on bats' morphology in the same forest and can provide essential information for assessing patterns of bat habitat use.

  19. Parallel sites implicate functional convergence of the hearing gene prestin among echolocating mammals.

    Science.gov (United States)

    Liu, Zhen; Qi, Fei-Yan; Zhou, Xin; Ren, Hai-Qing; Shi, Peng

    2014-09-01

    Echolocation is a sensory system whereby certain mammals navigate and forage using sound waves, usually in environments where visibility is limited. Curiously, echolocation has evolved independently in bats and whales, which occupy entirely different environments. Based on this phenotypic convergence, recent studies identified several echolocation-related genes with parallel sites at the protein sequence level among different echolocating mammals, and among these, prestin seems the most promising. Although previous studies analyzed the evolutionary mechanism of prestin, the functional roles of the parallel sites in the evolution of mammalian echolocation are not clear. By functional assays, we show that a key parameter of prestin function, 1/α, is increased in all echolocating mammals and that the N7T parallel substitution accounted for this functional convergence. Moreover, another parameter, V1/2, was shifted toward the depolarization direction in a toothed whale, the bottlenose dolphin (Tursiops truncatus) and a constant-frequency (CF) bat, the Stoliczka's trident bat (Aselliscus stoliczkanus). The parallel site of I384T between toothed whales and CF bats was responsible for this functional convergence. Furthermore, the two parameters (1/α and V1/2) were correlated with mammalian high-frequency hearing, suggesting that the convergent changes of the prestin function in echolocating mammals may play important roles in mammalian echolocation. To our knowledge, these findings present the functional patterns of echolocation-related genes in echolocating mammals for the first time and rigorously demonstrate adaptive parallel evolution at the protein sequence level, paving the way to insights into the molecular mechanism underlying mammalian echolocation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. The Effects of Attenuating Returning Echolocation Signals at the Lower Jaw of a Dolphin (Tursiops Truncatus)

    Science.gov (United States)

    1991-06-01

    echolocation signals are guided to the inner ear of odonto - relatively little loss of energy. The biochemical composition cete cetaceans via areas of fatty...pool, on the range of useful al. (1986), and others have provided evidence that odonto - energy in the emitted clicks. cete cetaceans emit echolocation

  1. Learning to echolocate in sighted people: a correlational study on attention, working memory and spatial abilities.

    Science.gov (United States)

    Ekkel, M R; van Lier, R; Steenbergen, B

    2017-03-01

    Echolocation can be beneficial for the orientation and mobility of visually impaired people. Research has shown considerable individual differences for acquiring this skill. However, individual characteristics that affect the learning of echolocation are largely unknown. In the present study, we examined individual factors that are likely to affect learning to echolocate: sustained and divided attention, working memory, and spatial abilities. To that aim, sighted participants with normal hearing performed an echolocation task that was adapted from a previously reported size-discrimination task. In line with existing studies, we found large individual differences in echolocation ability. We also found indications that participants were able to improve their echolocation ability. Furthermore, we found a significant positive correlation between improvement in echolocation and sustained and divided attention, as measured in the PASAT. No significant correlations were found with our tests regarding working memory and spatial abilities. These findings may have implications for the development of guidelines for training echolocation that are tailored to the individual with a visual impairment.

  2. Adaptive vocal behavior drives perception by echolocation in bats

    DEFF Research Database (Denmark)

    Moss, Cynthia F; Chiu, Chen; Surlykke, Annemarie

    2011-01-01

    Echolocation operates through adaptive sensorimotor systems that collectively enable the bat to localize and track sonar objects as it flies. The features of sonar signals used by a bat to probe its surroundings determine the information available to its acoustic imaging system. In turn, the bat......'s perception of a complex scene guides its active adjustments in the features of subsequent sonar vocalizations. Here, we propose that the bat's active vocal-motor behaviors play directly into its representation of a dynamic auditory scene....

  3. Concept development for an environmental impact assessment for off-shore wind parks in the Baltic States. Project November 2007 - October 2009. Final report. Advisory assistance programme for environmental protection in the countries of Central and Eastern Europe, the Caucasus and Central Asia

    Energy Technology Data Exchange (ETDEWEB)

    Fammler, Heidrun; Kuris, Merle [Baltic Environmental Forum, Riga (Latvia)

    2010-12-15

    This is the final report of the project ''Concept development for an environmental impact assessment for off-shore wind parks in the Baltic States'', which was co-funded by the German Environmental Agency (project No 380 01 173). The main outcomes of the project are: - The ''Guidelines for the investigation of the impacts of offshore wind farms on the marine environment in the Baltic States'' developed by the Baltic Environmental Forum and German consultant Dr. Jan Kube in consultation with experts from Estonia, Latvia and Lithuania. The guidelines give an overview on potential negative impacts of offshore wind farms on the marine environment and general EIA and monitoring requirements as well as give detailed guidance on methodology for relevant field investigations. - The background paper ''Legal frame for the use of offshore wind energy in Germany'' prepared by RA'in Dr. Ursula Prall (April 2009) - 3 international workshops on different aspects related to establishment of offshore wind farms and assessment of their environmental impacts. (orig.)

  4. Independent losses of visual perception genes Gja10 and Rbp3 in echolocating bats (Order: Chiroptera.

    Directory of Open Access Journals (Sweden)

    Bin Shen

    Full Text Available A trade-off between the sensory modalities of vision and hearing is likely to have occurred in echolocating bats as the sophisticated mechanism of laryngeal echolocation requires considerable neural processing and has reduced the reliance of echolocating bats on vision for perceiving the environment. If such a trade-off exists, it is reasonable to hypothesize that some genes involved in visual function may have undergone relaxed selection or even functional loss in echolocating bats. The Gap junction protein, alpha 10 (Gja10, encoded by Gja10 gene is expressed abundantly in mammal retinal horizontal cells and plays an important role in horizontal cell coupling. The interphotoreceptor retinoid-binding protein (Irbp, encoded by the Rbp3 gene is mainly expressed in interphotoreceptor matrix and is known to be critical for normal functioning of the visual cycle. We sequenced Gja10 and Rbp3 genes in a taxonomically wide range of bats with divergent auditory characteristics (35 and 18 species for Gja10 and Rbp3, respectively. Both genes have became pseudogenes in species from the families Hipposideridae and Rhinolophidae that emit constant frequency echolocation calls with Doppler shift compensation at high-duty-cycles (the most sophisticated form of biosonar known, and in some bat species that emit echolocation calls at low-duty-cycles. Our study thus provides further evidence for the hypothesis that a trade-off occurs at the genetic level between vision and echolocation in bats.

  5. Independent losses of visual perception genes Gja10 and Rbp3 in echolocating bats (Order: Chiroptera).

    Science.gov (United States)

    Shen, Bin; Fang, Tao; Dai, Mengyao; Jones, Gareth; Zhang, Shuyi

    2013-01-01

    A trade-off between the sensory modalities of vision and hearing is likely to have occurred in echolocating bats as the sophisticated mechanism of laryngeal echolocation requires considerable neural processing and has reduced the reliance of echolocating bats on vision for perceiving the environment. If such a trade-off exists, it is reasonable to hypothesize that some genes involved in visual function may have undergone relaxed selection or even functional loss in echolocating bats. The Gap junction protein, alpha 10 (Gja10, encoded by Gja10 gene) is expressed abundantly in mammal retinal horizontal cells and plays an important role in horizontal cell coupling. The interphotoreceptor retinoid-binding protein (Irbp, encoded by the Rbp3 gene) is mainly expressed in interphotoreceptor matrix and is known to be critical for normal functioning of the visual cycle. We sequenced Gja10 and Rbp3 genes in a taxonomically wide range of bats with divergent auditory characteristics (35 and 18 species for Gja10 and Rbp3, respectively). Both genes have became pseudogenes in species from the families Hipposideridae and Rhinolophidae that emit constant frequency echolocation calls with Doppler shift compensation at high-duty-cycles (the most sophisticated form of biosonar known), and in some bat species that emit echolocation calls at low-duty-cycles. Our study thus provides further evidence for the hypothesis that a trade-off occurs at the genetic level between vision and echolocation in bats.

  6. Different auditory feedback control for echolocation and communication in horseshoe bats.

    Directory of Open Access Journals (Sweden)

    Ying Liu

    Full Text Available Auditory feedback from the animal's own voice is essential during bat echolocation: to optimize signal detection, bats continuously adjust various call parameters in response to changing echo signals. Auditory feedback seems also necessary for controlling many bat communication calls, although it remains unclear how auditory feedback control differs in echolocation and communication. We tackled this question by analyzing echolocation and communication in greater horseshoe bats, whose echolocation pulses are dominated by a constant frequency component that matches the frequency range they hear best. To maintain echoes within this "auditory fovea", horseshoe bats constantly adjust their echolocation call frequency depending on the frequency of the returning echo signal. This Doppler-shift compensation (DSC behavior represents one of the most precise forms of sensory-motor feedback known. We examined the variability of echolocation pulses emitted at rest (resting frequencies, RFs and one type of communication signal which resembles an echolocation pulse but is much shorter (short constant frequency communication calls, SCFs and produced only during social interactions. We found that while RFs varied from day to day, corroborating earlier studies in other constant frequency bats, SCF-frequencies remained unchanged. In addition, RFs overlapped for some bats whereas SCF-frequencies were always distinctly different. This indicates that auditory feedback during echolocation changed with varying RFs but remained constant or may have been absent during emission of SCF calls for communication. This fundamentally different feedback mechanism for echolocation and communication may have enabled these bats to use SCF calls for individual recognition whereas they adjusted RF calls to accommodate the daily shifts of their auditory fovea.

  7. Does nasal echolocation influence the modularity of the mammal skull?

    Science.gov (United States)

    Santana, S E; Lofgren, S E

    2013-11-01

    In vertebrates, changes in cranial modularity can evolve rapidly in response to selection. However, mammals have apparently maintained their pattern of cranial integration throughout their evolutionary history and across tremendous morphological and ecological diversity. Here, we use phylogenetic, geometric morphometric and comparative analyses to test the hypothesis that the modularity of the mammalian skull has been remodelled in rhinolophid bats due to the novel and critical function of the nasal cavity in echolocation. We predicted that nasal echolocation has resulted in the evolution of a third cranial module, the 'nasal dome', in addition to the braincase and rostrum modules, which are conserved across mammals. We also test for similarities in the evolution of skull shape in relation to habitat across rhinolophids. We find that, despite broad variation in the shape of the nasal dome, the integration of the rhinolophid skull is highly consistent with conserved patterns of modularity found in other mammals. Across their broad geographical distribution, cranial shape in rhinolophids follows two major divisions that could reflect adaptations to dietary and environmental differences in African versus South Asian distributions. Our results highlight the potential of a relatively simple modular template to generate broad morphological and functional variation in mammals. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  8. Managing Clutter in a High Pulse Rate Echolocation System

    Directory of Open Access Journals (Sweden)

    Jacob Isbell

    2018-03-01

    Full Text Available The use of echolocation for navigating in dense, cluttered environments is a challenge due to the need for rapid sampling of nearby objects in the face of delayed echoes from distant objects. In the wild, echolocating bats frequently encounter this situation when leaving the roost or while hunting. If long-delay echoes from a distant object are received after the next pulse is sent out, these “aliased” echoes appear as close-range phantom objects. Little is known about how bats cope with these situations. In this work, we demonstrate a novel strategy to manage aliasing in cases where a single target is actively being tracked at close range. This paper presents three reactive strategies for a high pulse-rate sonar system to combat aliased echoes: (1 changing the interpulse interval to move the aliased echoes away in time from the tracked target, (2 changing positions to create a geometry without aliasing, and (3 a phase-based, transmission beam-shaping strategy to illuminate the target and not the aliasing object.

  9. Multi-component separation and analysis of bat echolocation calls.

    Science.gov (United States)

    DiCecco, John; Gaudette, Jason E; Simmons, James A

    2013-01-01

    The vast majority of animal vocalizations contain multiple frequency modulated (FM) components with varying amounts of non-linear modulation and harmonic instability. This is especially true of biosonar sounds where precise time-frequency templates are essential for neural information processing of echoes. Understanding the dynamic waveform design by bats and other echolocating animals may help to improve the efficacy of man-made sonar through biomimetic design. Bats are known to adapt their call structure based on the echolocation task, proximity to nearby objects, and density of acoustic clutter. To interpret the significance of these changes, a method was developed for component separation and analysis of biosonar waveforms. Techniques for imaging in the time-frequency plane are typically limited due to the uncertainty principle and interference cross terms. This problem is addressed by extending the use of the fractional Fourier transform to isolate each non-linear component for separate analysis. Once separated, empirical mode decomposition can be used to further examine each component. The Hilbert transform may then successfully extract detailed time-frequency information from each isolated component. This multi-component analysis method is applied to the sonar signals of four species of bats recorded in-flight by radiotelemetry along with a comparison of other common time-frequency representations.

  10. Acoustic features of objects matched by an echolocating bottlenose dolphin.

    Science.gov (United States)

    Delong, Caroline M; Au, Whitlow W L; Lemonds, David W; Harley, Heidi E; Roitblat, Herbert L

    2006-03-01

    The focus of this study was to investigate how dolphins use acoustic features in returning echolocation signals to discriminate among objects. An echolocating dolphin performed a match-to-sample task with objects that varied in size, shape, material, and texture. After the task was completed, the features of the object echoes were measured (e.g., target strength, peak frequency). The dolphin's error patterns were examined in conjunction with the between-object variation in acoustic features to identify the acoustic features that the dolphin used to discriminate among the objects. The present study explored two hypotheses regarding the way dolphins use acoustic information in echoes: (1) use of a single feature, or (2) use of a linear combination of multiple features. The results suggested that dolphins do not use a single feature across all object sets or a linear combination of six echo features. Five features appeared to be important to the dolphin on four or more sets: the echo spectrum shape, the pattern of changes in target strength and number of highlights as a function of object orientation, and peak and center frequency. These data suggest that dolphins use multiple features and integrate information across echoes from a range of object orientations.

  11. Spike Neuromorphic VLSI-Based Bat Echolocation for Micro-Aerial Vehicle Guidance

    National Research Council Canada - National Science Library

    Horiuchi, Timothy K; Krishnaprasad, P. S

    2007-01-01

    .... This includes multiple efforts related to a VLSI-based echolocation system being developed in one of our laboratories from algorithm development, bat flight data analysis, to VLSI circuit design...

  12. Echolocating bats cry out loud to detect their prey.

    Directory of Open Access Journals (Sweden)

    Annemarie Surlykke

    Full Text Available Echolocating bats have successfully exploited a broad range of habitats and prey. Much research has demonstrated how time-frequency structure of echolocation calls of different species is adapted to acoustic constraints of habitats and foraging behaviors. However, the intensity of bat calls has been largely neglected although intensity is a key factor determining echolocation range and interactions with other bats and prey. Differences in detection range, in turn, are thought to constitute a mechanism promoting resource partitioning among bats, which might be particularly important for the species-rich bat assemblages in the tropics. Here we present data on emitted intensities for 11 species from 5 families of insectivorous bats from Panamá hunting in open or background cluttered space or over water. We recorded all bats in their natural habitat in the field using a multi-microphone array coupled with photographic methods to assess the bats' position in space to estimate emitted call intensities. All species emitted intense search signals. Output intensity was reduced when closing in on background by 4-7 dB per halving of distance. Source levels of open space and edge space foragers (Emballonuridae, Mormoopidae, Molossidae, and Vespertilionidae ranged between 122-134 dB SPL. The two Noctilionidae species hunting over water emitted the loudest signals recorded so far for any bat with average source levels of ca. 137 dB SPL and maximum levels above 140 dB SPL. In spite of this ten-fold variation in emitted intensity, estimates indicated, surprisingly, that detection distances for prey varied far less; bats emitting the highest intensities also emitted the highest frequencies, which are severely attenuated in air. Thus, our results suggest that bats within a local assemblage compensate for frequency dependent attenuation by adjusting the emitted intensity to achieve comparable detection distances for prey across species. We conclude that for bats

  13. Anthropogenic noise alters bat activity levels and echolocation calls

    Directory of Open Access Journals (Sweden)

    Jessie P. Bunkley

    2015-01-01

    Full Text Available Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, which can potentially interfere with signal reception and processing. Compressor stations associated with natural gas extraction produce broadband noise 24 hours a day, 365 days a year. With over half a million producing gas wells in the U.S. this infrastructure is a major source of noise pollution across the landscape. We conducted a ‘natural experiment’ in the second largest gas extraction field in the U.S. to investigate the potential effects of gas compressor station noise on the activity levels of the local bat assemblage. We used acoustic monitoring to compare the activity level (number of minutes in a night with a bat call of the bat assemblage at sites with compressor stations to sites lacking this infrastructure. We found that activity levels for the Brazilian free-tailed bat (Tadarida brasiliensis were 40% lower at loud compressor sites compared to quieter well pads, whereas the activity levels of four other species (Myotis californicus, M. cillolabrum, M. lucifugus, Parastrellus hesperus were not affected by noise. Furthermore, our results reveal that the assemblage of bat species emitting low frequency (35 kHz echolocation did not exhibit altered activity levels in noise. Lower activity levels of Brazilian free-tailed bats at loud sites indicate a potential reduction in habitat for this species. Additionally, a comparison of echolocation search calls produced by free-tailed bats at sites with and without compressor stations reveal that this species modifies its echolocation search calls in noise—producing longer calls with a narrower bandwidth. Call alterations might affect prey

  14. Scour around monopile foundations for off-shore wind turbines

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Frigaard, Peter; Martinelli, Luca

    2006-01-01

    The present paper aims to describe the scour hole process around large piles through laboratory tests under waves, unidirectional and tidal currents in time. The process for unidirectional and tidal currents has been compared. The tests have been carried out in a wave flume equipped with a two wa...... recirculation pump at the Hydraulic Laboratory at Aalborg University. The mobile bed around the model was leveled with an automatic laser profiler and the results are graphically displayed as maximum scour depths and eroded volumes....

  15. Technologies for waste heat recovery in off-shore applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Haglind, Fredrik; Kandepu, Rambabu

    2013-01-01

    different technologies are presented, considering the Draugen platform in the North Sea as a base case. The Turboden 65-HRS unit is considered as representative of the organic Rankine cycle technology. Air bottoming cycles are analyzed and optimal design pressure ratios are selected. We also study a one...... pressure level steam Rankine cycle employing the once-through heat recovery steam generator without bypass stack. We compare the three technologies considering the combined cycle thermal efficiency, the weight, the net present value, the profitability index and payback time. Both incomes related to CO2...... of the unit is expected to be around 250 ton. The air bottoming cycle without intercooling is also a possible alternative due to its low weight (76 ton) and low investment cost (8.8 M$). However, cycle performance and profitability index are poorer, 12.1% and 0.75. Furthermore, the results suggest...

  16. Utgrunden off-shore wind farm - Measurements of underwater noise

    International Nuclear Information System (INIS)

    Lindell, Hans

    2003-07-01

    Airicole, GE Wind Energy and SEAS/Energi E2 have initiated this project in order to achieve a better understanding on how offshore based wind farms effect the underwater noise. The main reason is to gain knowledge on how marine wildlife could be effected by this kind of installation. The measurements were performed at Utgrunden wind farm that is situated at the reef Utgrunden on the Swedish southeast coast. The farm consists of seven 1,5 MW turbines. Three hydrophones registered the underwater sound and four accelerometers the tower vibrations. The measurement campaign was conducted during a period from November 2002 to February 2003. The objectives with this project is to answer the following issues and its results are: 1. What is the character of sound from a single power station? - The turbines radiate sound mainly at a few dominating frequencies from 30 Hz up to 800 Hz. At frequencies below 3 Hz no contribution from the turbines can be detected due to the high background level from the waves and the low tower vibration level. 2. What are the sound generating mechanisms in the turbine? - Gearbox mesh frequency vibrations that are transmitted via the tower structure and radiated out to the water mainly generate the sound. Airborne blade sound is effectively dampened in the transition from air to water. 3. How does the sound attenuate with increasing distance at different frequencies? - The average attenuation per doubled distance for frequencies between 31 Hz and 722 Hz is approximately 4 dB in the measured positions. No clear frequency dependence could be found. 4. How does the sound pressure level vary with increasing wind speed? - With increasing wind speed, the sound pressure level increases and the dominating frequencies move upward due to increasing turbine rotational speed. 5. How does sound from different power stations interfere with each other and influence the over all sound image? - No clear tendencies of interference could be observed in this study. This could be due to small variations in turbine speed and that the hydrophone positions needs to be less dominated by a single turbine. 6. How is a passing ship influencing the sound level in the farm? - Passages of ship dominates the sound in the park for frequency higher than approx. 63 Hz. There is a strong dependence of type of ship, distance etc

  17. An assessment of two off-shore igniter concepts

    International Nuclear Information System (INIS)

    Guenette, C. C.

    1997-01-01

    On June 12, 1996, two controlled in-situ oil spill burns (ISB), using a response-prepared ISB system, were conducted in the North Sea, 40 miles off the U. K. coast. The first burn involved fresh crude oil and was ignited with a hand-held igniter using a standard gelled fuel mixture. In the second burn an emulsified crude was used, ignited with a prototype emulsion breaking igniter (EBI) deployed using the Helitorch. The objective was to determine operational practicalities under realistic conditions when responding to a weathered oil situation in an offshore location. This paper is devoted to an assessment of the two igniter systems used during the trials. Results showed that oil aged by 12 hours with a 25 per cent water content burned down to a three-to-four per cent residue. The fire burn survived the two burns intact. The hand-held ignition system worked with fresh oil and the Helitorch lit emulsified oil using EBI. These trials were the first time that the EBI was deployed from a Helitorch slung beneath a helicopter. It was concluded that (1) the simplicity of the logistics required for the hand-held igniter would favour its use over the Helitorch method for fresh or lightly weathered oil, (2) more heavily weathered oils would require the use of an emulsion-breaking type igniter, and (3) aerial deployment of igniters offer the advantage of allowing more accurate positioning. 10 refs.,5 tabs., 3 figs

  18. Microcomputers take over in off-shore process

    Energy Technology Data Exchange (ETDEWEB)

    Claricoates, J

    1978-10-01

    The special capabilities and adaptability of microcomputers are typically demonstrated by the use of them on Mobil Exploration, Norway, Inc.'s Statfjord A Condeep platform. One of the unique features of offshore oil production is that so many different operations are conducted in a very confined space. On Statfjord A drilling, production, storage of crude oil, gas compression for sale or reinjection, custody transfer, generation and distribution of a significant amount of electric power, a hotel facility, and flight operations, all have to be accommodated and controlled. Superimposed on these are comprehensive fire detection and shutdown systems. In such a highly complex, densely packed, and highly interactive environment, a supervisory control and data acquisition system (SCADA) by providing coordinated and easily read displays, better records for alarm analysis, and possibly suggesting corrective action when a fault does occur, is an essential aid to an operator, whose decisions must always by correct.

  19. Modelling the Pultrusion Process of Off Shore Wind Turbine Blades

    DEFF Research Database (Denmark)

    Baran, Ismet

    together with the thermal and cure developments are addressed. A detailed survey on pultrusion is presented including numerical and experimental studies available in the literature since the 1980s. Keeping the multi-physics and large amount of variables involved in the pultrusion process in mind...... and shape distortions in the pultrusion process. Together these models present a thermo-chemical-mechanical model framework for the process which is unprecedented in literature. In this framework, the temperature and degree of cure fields already calculated in the thermo-chemical model are mapped...

  20. Modelling the pultrusion process of off shore wind turbine blades

    NARCIS (Netherlands)

    Baran, Ismet

    This thesis is devoted to the numerical modelling of the pultrusion process for industrial products such as wind turbine blades and structural profiles. The main focus is on the thermo-chemical and mechanical analyses of the process in which the process induced tresses and shape distortions together

  1. Stochastic simulation of off-shore oil terminal systems

    International Nuclear Information System (INIS)

    Frankel, E.G.; Oberle, J.

    1991-01-01

    To cope with the problem of uncertainty and conditionality in the planning, design, and operation of offshore oil transshipment terminal systems, a conditional stochastic simulation approach is presented. Examples are shown, using SLAM II, a computer simulation language based on GERT, a conditional stochastic network analysis methodology in which use of resources such as time and money are expressed by the moment generating function of the statistics of the resource requirements. Similarly each activity has an associated conditional probability of being performed and/or of requiring some of the resources. The terminal system is realistically represented by modelling the statistics of arrivals, loading and unloading times, uncertainties in costs and availabilities, etc

  2. Spike Neuromorphic VLSI-Based Bat Echolocation for Micro-Aerial Vehicle Guidance

    Science.gov (United States)

    2007-03-31

    IFinal 03/01/04 - 02/28/07 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Neuromorphic VLSI-based Bat Echolocation for Micro-aerial 5b.GRANTNUMBER Vehicle...uncovered interesting new issues in our choice for representing the intensity of signals. We have just finished testing the first chip version of an echo...timing-based algorithm (’openspace’) for sonar-guided navigation amidst multiple obstacles. 15. SUBJECT TERMS Neuromorphic VLSI, bat echolocation

  3. Echolocation by the harbour porpoise: Life in coastal waters

    Directory of Open Access Journals (Sweden)

    Lee Anton Miller

    2013-04-01

    Full Text Available The harbour porpoise is one of the smallest and most widely spread of all toothed whales. They are found abundantly in coastal waters all around the northern hemisphere. They are among the 11 species known to use high frequency sonar of relative narrow bandwidth. Their narrow biosonar beam helps isolate echoes from prey among those from unwanted items and noise. Obtaining echoes from small objects like net mesh, net floats and small prey is facilitated by the very high peak frequency around 130 kHz with a wavelength of about 12 mm. We argue that such echolocation signals and narrow band auditory filters give the harbour porpoise a selective advantage in a coastal environment. Predation by killer whales and a minimum noise region in the ocean around 130 kHz may have provided selection pressures for using this frequency band for biosonar signals.

  4. Directionality of nose-emitted echolocation calls from bats without a nose leaf (Plecotus auritus).

    Science.gov (United States)

    Jakobsen, Lasse; Hallam, John; Moss, Cynthia F; Hedenström, Anders

    2018-02-13

    All echolocating bats and whales measured to date emit a directional bio-sonar beam that affords them a number of advantages over an omni-directional beam, i.e. reduced clutter, increased source level and inherent directional information. In this study, we investigated the importance of directional sound emission for navigation through echolocation by measuring the sonar beam of brown long-eared bats, Plecotus auritus Plecotus auritus emits sound through the nostrils but has no external appendages to readily facilitate a directional sound emission as found in most nose emitters. The study shows that P. auritus , despite lacking an external focusing apparatus, emits a directional echolocation beam (directivity index=13 dB) and that the beam is more directional vertically (-6 dB angle at 22 deg) than horizontally (-6 dB angle at 35 deg). Using a simple numerical model, we found that the recorded emission pattern is achievable if P. auritus emits sound through the nostrils as well as the mouth. The study thus supports the hypothesis that a directional echolocation beam is important for perception through echolocation and we propose that animals with similarly non-directional emitter characteristics may facilitate a directional sound emission by emitting sound through both the nostrils and the mouth. © 2018. Published by The Company of Biologists Ltd.

  5. Blindness enhances auditory obstacle circumvention: Assessing echolocation, sensory substitution, and visual-based navigation.

    Science.gov (United States)

    Kolarik, Andrew J; Scarfe, Amy C; Moore, Brian C J; Pardhan, Shahina

    2017-01-01

    Performance for an obstacle circumvention task was assessed under conditions of visual, auditory only (using echolocation) and tactile (using a sensory substitution device, SSD) guidance. A Vicon motion capture system was used to measure human movement kinematics objectively. Ten normally sighted participants, 8 blind non-echolocators, and 1 blind expert echolocator navigated around a 0.6 x 2 m obstacle that was varied in position across trials, at the midline of the participant or 25 cm to the right or left. Although visual guidance was the most effective, participants successfully circumvented the obstacle in the majority of trials under auditory or SSD guidance. Using audition, blind non-echolocators navigated more effectively than blindfolded sighted individuals with fewer collisions, lower movement times, fewer velocity corrections and greater obstacle detection ranges. The blind expert echolocator displayed performance similar to or better than that for the other groups using audition, but was comparable to that for the other groups using the SSD. The generally better performance of blind than of sighted participants is consistent with the perceptual enhancement hypothesis that individuals with severe visual deficits develop improved auditory abilities to compensate for visual loss, here shown by faster, more fluid, and more accurate navigation around obstacles using sound.

  6. Blindness enhances auditory obstacle circumvention: Assessing echolocation, sensory substitution, and visual-based navigation.

    Directory of Open Access Journals (Sweden)

    Andrew J Kolarik

    Full Text Available Performance for an obstacle circumvention task was assessed under conditions of visual, auditory only (using echolocation and tactile (using a sensory substitution device, SSD guidance. A Vicon motion capture system was used to measure human movement kinematics objectively. Ten normally sighted participants, 8 blind non-echolocators, and 1 blind expert echolocator navigated around a 0.6 x 2 m obstacle that was varied in position across trials, at the midline of the participant or 25 cm to the right or left. Although visual guidance was the most effective, participants successfully circumvented the obstacle in the majority of trials under auditory or SSD guidance. Using audition, blind non-echolocators navigated more effectively than blindfolded sighted individuals with fewer collisions, lower movement times, fewer velocity corrections and greater obstacle detection ranges. The blind expert echolocator displayed performance similar to or better than that for the other groups using audition, but was comparable to that for the other groups using the SSD. The generally better performance of blind than of sighted participants is consistent with the perceptual enhancement hypothesis that individuals with severe visual deficits develop improved auditory abilities to compensate for visual loss, here shown by faster, more fluid, and more accurate navigation around obstacles using sound.

  7. The role of tragus on echolocating bat, Eptesicus fuscus

    Science.gov (United States)

    Chiu, Chen; Moss, Cynthia

    2005-04-01

    Echolocating bats produce ultrasonic vocal signals and utilize the returning echoes to detect, localize and track prey, and also to avoid obstacles. The pinna and tragus, two major components of the bats external ears, play important roles in filtering returning echoes. The tragus is generally believed to play a role in vertical sound localization. The purpose of this study is to further examine how manipulation of the tragus affects a free-flying bat's prey capture and obstacle avoidance behavior. The first part of this study involved a prey capture experiment, and the bat was trained to catch the tethered mealworms in a large room. The second experiment involved obstacle avoidance, and the bat's task was to fly through the largest opening from a horizontal wire array without touching the wires. In both experiments, the bat performed the tasks under three different conditions: with intact tragus, tragus-deflection and recovery from tragus-deflection. Significantly lower performance was observed in both experiments when tragi were glued down. However, the bat adjusted quickly and returned to baseline performance a few days after the manipulation. The results suggest that tragus-deflection does have effects on both the prey capture and obstacle avoidance behavior. [Work supported by NSF.

  8. Echolocating bats emit a highly directional sonar sound beam in the field

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Boel Pedersen, Simon; Jakobsen, Lasse

    2009-01-01

    Bats use echolocation or biosonar to navigate and find prey at night. They emit short ultrasonic calls and listen for reflected echoes. The beam width of the calls is central to the function of the sonar, but directionality of echolocation calls has never been measured from bats flying in the wild....... We used a microphone array to record sounds and determine horizontal directionality for echolocation calls of the trawling Daubenton's bat, Myotis daubentonii, flying over a pond in its natural habitat. Myotis daubentonii emitted highly directional calls in the field. Directionality increased...... and directionality can be explained by the simple piston model. The model also suggests that the increase in the emitted intensity in the field is caused by the increased directionality, focusing sound energy in the forward direction. The bat may increase directionality by opening the mouth wider to emit a louder...

  9. Intense echolocation calls from two ;whispering' bats, Artibeus jamaicensis and Macrophyllum macrophyllum (Phyllostomidae)

    DEFF Research Database (Denmark)

    Brinkløv, Signe; Kalko, Elisabeth K V; Surlykke, Annemarie

    2009-01-01

    Bats use echolocation to exploit a variety of habitats and food types. Much research has documented how frequency-time features of echolocation calls are adapted to acoustic constraints imposed by habitat and prey but emitted sound intensities have received little attention. Bats from the family...... of Phyllostomidae have been categorised as low intensity (whispering) gleaners, assumed to emit echolocation calls with low source levels (approximately 70 dB SPL measured 10 cm from the bat's mouth). We used a multi-microphone array to determine intensities emitted from two phyllostomid bats from Panamá...... room. Both species emitted surprisingly intense signals with maximum source levels of 105 dB SPL r.m.s. for M. macrophyllum and 110 dB SPL r.m.s. for A. jamaicensis, hence much louder than a ;whisper'. M. macrophyllum was consistently loud (mean source level 101 dB SPL) whereas A. jamaicensis showed...

  10. Recording and quantification of ultrasonic echolocation clicks from free-ranging toothed whales

    DEFF Research Database (Denmark)

    Madsen, Peter Teglberg; Wahlberg, Magnus

    2007-01-01

    Toothed whales produce short, ultrasonic clicks of high directionality and source level to probe their environment acoustically. This process, termed echolocation, is to a large part governed by the properties of the emitted clicks. Therefore derivation of click source parameters from free......-ranging animals is of increasing importance to understand both how toothed whales use echolocation in the wild and how they may be monitored acoustically. This paper addresses how source parameters can be derived from free-ranging toothed whales in the wild using calibrated multi-hydrophone arrays and digital...... of discrete versions of toothed whale clicks that are meaningful in a biosonar context....

  11. Recognition of aspect-dependent three-dimensional objects by an echolocating Atlantic bottlenose dolphin.

    Science.gov (United States)

    Helweg, D A; Roitblat, H L; Nachtigall, P E; Hautus, M J

    1996-01-01

    We examined the ability of a bottlenose dolphin (Tursiops truncatus) to recognize aspect-dependent objects using echolocation. An aspect-dependent object such as a cube produces acoustically different echoes at different angles relative to the echolocation signal. The dolphin recognized the objects even though the objects were free to rotate and sway. A linear discriminant analysis and nearest centroid classifier could classify the objects using average amplitude, center frequency, and bandwidth of object echoes. The results show that dolphins can use varying acoustic properties to recognize constant objects and suggest that aspect-independent representations may be formed by combining information gleaned from multiple echoes.

  12. Imidacloprid toxicity impairs spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas.

    Science.gov (United States)

    Hsiao, Chun-Jen; Lin, Ching-Lung; Lin, Tian-Yu; Wang, Sheue-Er; Wu, Chung-Hsin

    2016-04-13

    It has been reported that the decimation of honey bees was because of pesticides of imidacloprid. The imidacloprid is a wildly used neonicotinoid insecticide. However, whether imidacloprid toxicity interferes with the spatial memory of echolocation bats is still unclear. Thus, we compared the spatial memory of Formosan leaf-nosed bats, Hipposideros terasensis, before and after chronic treatment with a low dose of imidacloprid. We observed that stereotyped flight patterns of echolocation bats that received chronic imidacloprid treatment were quite different from their originally learned paths. We further found that neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas of echolocation bats that received imidacloprid treatment was significantly enhanced in comparison with echolocation bats that received sham treatment. Thus, we suggest that imidacloprid toxicity may interfere with the spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas. The results provide direct evidence that pesticide toxicity causes a spatial memory disorder in echolocation bats. This implies that agricultural pesticides may pose severe threats to the survival of echolocation bats.

  13. New model for gain control of signal intensity to object distance in echolocating bats

    DEFF Research Database (Denmark)

    Nørum, Ulrik; Brinkløv, Signe; Surlykke, Annemarie

    2012-01-01

    Echolocating bats emit ultrasonic calls and listen for the returning echoes to orient and localize prey in darkness. The emitted source level, SL (estimated signal intensity 10 cm from the mouth), is adjusted dynamically from call to call in response to sensory feedback as bats approach objects. ...

  14. Morphological correlates of echolocation frequency in the endemic Cape horseshoe bat, Rhinolophus capensis (Chiroptera: Rhinolophidae).

    Science.gov (United States)

    Odendaal, Lizelle J; Jacobs, David S

    2011-05-01

    We investigated intraspecific variation in echolocation calls of the Cape horseshoe bat, Rhinolophus capensis, by comparing echolocation and associated morphological parameters among individuals from three populations of this species. The populations were situated in the center and at the western and eastern limits of the distribution of R. capensis. The latter two populations were situated in ecotones between vegetation biomes. Ecotone populations deviated slightly from the allometric relationship between body size and peak frequency for the genus, and there was no relationship between these variables within R. capensis. Nasal chamber length was the best predictor of peak frequency but not correlated with body size. The evolution of echolocation thus appears to have been uncoupled from body size in R. capensis. Furthermore, females used higher frequencies than males, which imply a potential social role for peak frequency. The differences in peak frequency may have originated from random founder effects and then compounded by genetic drift and/or natural selection. The latter may have acted directly on peak frequency altering skull parameters involved in echolocation independently of body size, resulting in the evolution of local acoustic signatures.

  15. Moth wing scales slightly increase the absorbance of bat echolocation calls.

    Directory of Open Access Journals (Sweden)

    Jinyao Zeng

    Full Text Available Coevolutionary arms races between predators and prey can lead to a diverse range of foraging and defense strategies, such as countermeasures between nocturnal insects and echolocating bats. Here, we show how the fine structure of wing scales may help moths by slightly increasing sound absorbance at frequencies typically used in bat echolocation. Using four widespread species of moths and butterflies, we found that moth scales are composed of honeycomb-like hollows similar to sound-absorbing material, but these were absent from butterfly scales. Micro-reverberation chamber experiments revealed that moth wings were more absorbent at the frequencies emitted by many echolocating bats (40-60 kHz than butterfly wings. Furthermore, moth wings lost absorbance at these frequencies when scales were removed, which suggests that some moths have evolved stealth tactics to reduce their conspicuousness to echolocating bats. Although the benefits to moths are relatively small in terms of reducing their target strengths, scales may nonetheless confer survival advantages by reducing the detection distances of moths by bats by 5-6%.

  16. Single source sound production and dynamic beam formation in echolocating harbour porpoises (Phocoena phocoena)

    DEFF Research Database (Denmark)

    Madsen, Peter Teglberg; Wisniewska, Danuta Maria; Beedholm, Kristian

    2010-01-01

    of three echolocating porpoises (Phocoena phocoena) with symmetrical pairs of phonic lips. Using time of arrival differences on three hydrophones, we show that all recorded clicks from these three porpoises are produced by the right pair of phonic lips with no evidence of simultaneous or independent...

  17. Vocal reporting of echolocation targets: dolphins often report before click trains end.

    Science.gov (United States)

    Ridgway, S H; Elsberry, W R; Blackwood, D J; Kamolnick, T; Todd, M; Carder, D A; Chaplin, Monica; Cranford, T W

    2012-01-01

    Bottlenose dolphins (Tursiops truncatus) wore opaque suction cups over their eyes while stationing behind an acoustically opaque door. This put the dolphins in a known position and orientation. When the door opened, the dolphin clicked to detect targets. Trainers specified that Dolphin S emit a whistle if the target was a 7.5 cm water filled sphere, or a pulse burst if the target was a rock. S remained quiet if there was no target. Dolphin B whistled for the sphere. She remained quiet for rock and for no target. Thus, S had to choose between three different responses, whistle, pulse burst, or remain quiet. B had to choose between two different responses, whistle or remain quiet. S gave correct vocal responses averaging 114 ms after her last echolocation click (range 182 ms before and 219 ms after the last click). Average response for B was 21 ms before her last echolocation click (range 250 ms before and 95 ms after the last click in the train). More often than not, B began her whistle response before her echolocation train ended. The findings suggest separate neural pathways for generation of response vocalizations as opposed to echolocation clicks. © 2012 Acoustical Society of America.

  18. Echolocation intensity and directionality of perching and flying fringe-lipped bats, Trachops cirrhosus (Phyllostomidae)

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Jakobsen, Lasse; Kalko, Elisabeth K V

    2013-01-01

    The Neotropical frog-eating bat, Trachops cirrhosus, primarily hunts stationary prey, either by gleaning on the wing, or in a sit-and-wait mode hanging from a perch. It listens passively for prey-generated sounds, but uses echolocation in all stages of the hunt. Like other bats in the family...

  19. Dynamics of the echolocation beam during prey pursuit in aerial hawking bats

    DEFF Research Database (Denmark)

    Jakobsen, Lasse; Olsen, Mads Nedergaard; Surlykke, Annemarie

    2015-01-01

    " than the vespertilionids, but ensonifying objects far ahead suggesting more clutter. Thus, beam broadening is not a fundamental property of the echolocation system. However, based on the results, we hypothesize that increased peripheral detection is crucial to all aerial hawking bats in the final...

  20. Auditory opportunity and visual constraint enabled the evolution of echolocation in bats

    DEFF Research Database (Denmark)

    Thiagavel, Jeneni; Cechetto, Clément; Santana, Sharlene E

    2018-01-01

    and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation...

  1. Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat

    NARCIS (Netherlands)

    Simon, Ralph; Holderied, Marc W.; Von Helversen, Otto

    Nectar feeding bats use echolocation to find their flowers in the dense growth of tropical rainforests, and such flowers have evolved acoustic features that make their echo more conspicuous to their pollinators. To shed light on the sensory and cognitive basis of echoacoustic object recognition we

  2. Evolution of the heteroharmonic strategy for target-range computation in the echolocation of Mormoopidae.

    Directory of Open Access Journals (Sweden)

    Emanuel C Mora

    2013-06-01

    Full Text Available Echolocating bats use the time elapsed from biosonar pulse emission to the arrival of echo (defined as echo-delay to assess target-distance. Target-distance is represented in the brain by delay-tuned neurons that are classified as either heteroharmonic or homoharmormic. Heteroharmonic neurons respond more strongly to pulse-echo pairs in which the timing of the pulse is given by the fundamental biosonar harmonic while the timing of echoes is provided by one (or several of the higher order harmonics. On the other hand, homoharmonic neurons are tuned to the echo delay between similar harmonics in the emitted pulse and echo. It is generally accepted that heteroharmonic computations are advantageous over homoharmonic computations; i.e. heteroharmonic neurons receive information from call and echo in different frequency-bands which helps to avoid jamming between pulse and echo signals. Heteroharmonic neurons have been found in two species of the family Mormoopidae (Pteronotus parnellii and Pteronotus quadridens and in Rhinolophus rouxi. Recently, it was proposed that heteroharmonic target-range computations are a primitive feature of the genus Pteronotus that was preserved in the evolution of the genus. Here we review recent findings on the evolution of echolocation in Mormoopidae, and try to link those findings to the evolution of the heteroharmonic computation strategy. We stress the hypothesis that the ability to perform heteroharmonic computations evolved separately from the ability of using long constant-frequency echolocation calls, high duty cycle echolocation and Doppler Shift Compensation. Also, we present the idea that heteroharmonic computations might have been of advantage for categorizing prey size, hunting eared insects and living in large conspecific colonies. We make five testable predictions that might help future investigations to clarify the evolution of the heteroharmonic echolocation in Mormoopidae and other families.

  3. The Voltage-Gated Potassium Channel Subfamily KQT Member 4 (KCNQ4) Displays Parallel Evolution in Echolocating Bats

    Science.gov (United States)

    Liu, Yang; Han, Naijian; Franchini, Lucía F.; Xu, Huihui; Pisciottano, Francisco; Elgoyhen, Ana Belén; Rajan, Koilmani Emmanuvel; Zhang, Shuyi

    2012-01-01

    Bats are the only mammals that use highly developed laryngeal echolocation, a sensory mechanism based on the ability to emit laryngeal sounds and interpret the returning echoes to identify objects. Although this capability allows bats to orientate and hunt in complete darkness, endowing them with great survival advantages, the genetic bases underlying the evolution of bat echolocation are still largely unknown. Echolocation requires high-frequency hearing that in mammals is largely dependent on somatic electromotility of outer hair cells. Then, understanding the molecular evolution of outer hair cell genes might help to unravel the evolutionary history of echolocation. In this work, we analyzed the molecular evolution of two key outer hair cell genes: the voltage-gated potassium channel gene KCNQ4 and CHRNA10, the gene encoding the α10 nicotinic acetylcholine receptor subunit. We reconstructed the phylogeny of bats based on KCNQ4 and CHRNA10 protein and nucleotide sequences. A phylogenetic tree built using KCNQ4 amino acid sequences showed that two paraphyletic clades of laryngeal echolocating bats grouped together, with eight shared substitutions among particular lineages. In addition, our analyses indicated that two of these parallel substitutions, M388I and P406S, were probably fixed under positive selection and could have had a strong functional impact on KCNQ4. Moreover, our results indicated that KCNQ4 evolved under positive selection in the ancestral lineage leading to mammals, suggesting that this gene might have been important for the evolution of mammalian hearing. On the other hand, we found that CHRNA10, a gene that evolved adaptively in the mammalian lineage, was under strong purifying selection in bats. Thus, the CHRNA10 amino acid tree did not show echolocating bat monophyly and reproduced the bat species tree. These results suggest that only a subset of hearing genes could underlie the evolution of echolocation. The present work continues to

  4. Testing Convergent Evolution in Auditory Processing Genes between Echolocating Mammals and the Aye-Aye, a Percussive-Foraging Primate.

    Science.gov (United States)

    Bankoff, Richard J; Jerjos, Michael; Hohman, Baily; Lauterbur, M Elise; Kistler, Logan; Perry, George H

    2017-07-01

    Several taxonomically distinct mammalian groups-certain microbats and cetaceans (e.g., dolphins)-share both morphological adaptations related to echolocation behavior and strong signatures of convergent evolution at the amino acid level across seven genes related to auditory processing. Aye-ayes (Daubentonia madagascariensis) are nocturnal lemurs with a specialized auditory processing system. Aye-ayes tap rapidly along the surfaces of trees, listening to reverberations to identify the mines of wood-boring insect larvae; this behavior has been hypothesized to functionally mimic echolocation. Here we investigated whether there are signals of convergence in auditory processing genes between aye-ayes and known mammalian echolocators. We developed a computational pipeline (Basic Exon Assembly Tool) that produces consensus sequences for regions of interest from shotgun genomic sequencing data for nonmodel organisms without requiring de novo genome assembly. We reconstructed complete coding region sequences for the seven convergent echolocating bat-dolphin genes for aye-ayes and another lemur. We compared sequences from these two lemurs in a phylogenetic framework with those of bat and dolphin echolocators and appropriate nonecholocating outgroups. Our analysis reaffirms the existence of amino acid convergence at these loci among echolocating bats and dolphins; some methods also detected signals of convergence between echolocating bats and both mice and elephants. However, we observed no significant signal of amino acid convergence between aye-ayes and echolocating bats and dolphins, suggesting that aye-aye tap-foraging auditory adaptations represent distinct evolutionary innovations. These results are also consistent with a developing consensus that convergent behavioral ecology does not reliably predict convergent molecular evolution. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  5. To females of a noctuid moth, male courtship songs are nothing more than bat echolocation calls

    DEFF Research Database (Denmark)

    Nakano, Ryo; Takanashi, Takuma; Skals, Niels

    2010-01-01

    It has been proposed that intraspecific ultrasonic communication observed in some moths evolved, through sexual selection, subsequent to the development of ears sensitive to echolocation calls of insectivorous bats. Given this scenario, the receiver bias model of signal evolution argues that acou......It has been proposed that intraspecific ultrasonic communication observed in some moths evolved, through sexual selection, subsequent to the development of ears sensitive to echolocation calls of insectivorous bats. Given this scenario, the receiver bias model of signal evolution argues...... production in the male moth, and subsequently the role of the sound with reference to the female's ability to discriminate male courtship songs from bat calls. We found that males have sex-specific tymbals for ultrasound emission, and that the broadcast of either male songs or simulated bat calls equally...

  6. Frequency alternation and an offbeat rhythm indicate foraging behavior in the echolocating bat, Saccopteryx bilineata

    DEFF Research Database (Denmark)

    Ratcliffe, John M; Jakobsen, Lasse; Kalko, Elisabeth K V

    2011-01-01

    The greater sac-winged bat, Saccopteryx bilineata (Emballonuridae), uses two distinct echolocation call sequences: a 'monotonous' sequence, where bats emit ~48 kHz calls at a relatively stable rate, and a frequency-alternating sequence, where bats emit calls at ~45 kHz (low-note call) and ~48 k......Hz (high-note call). The frequencies of these low-high-note pairs remain stable within sequences. In Panama, we recorded echolocation calls from S. bilineata with a multi-microphone array at two sites: one a known roosting site, the other a known foraging site. Our results indicate that this species (1......) only produces monotonous sequences in non-foraging contexts and, at times, directly after emitting a feeding buzz and (2) produces frequency-alternating sequences when actively foraging. These latter sequences are also characterized by an unusual, offbeat emission rhythm. We found significant positive...

  7. Effect of Broadband Nature of Marine Mammal Echolocation Clicks on Click-Based Population Density Estimates

    Science.gov (United States)

    2014-09-30

    No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing...will be applied also to other species such as sperm whale (Physeter macrocephalus) (whose high source level assures long range detection and amplifies...improve the accuracy of marine mammal density estimation based on counting echolocation clicks, and will be applicable to density estimates obtained

  8. Echolocation signals of the greater horseshoe bat (Rhinolophus ferrumequinum) in transfer flight and during landing.

    Science.gov (United States)

    Tian, B; Schnitzler, H U

    1997-04-01

    Echolocation signals of horseshoe bats (Rhinolophidae) consist of a relatively long component of constant frequency (CF) which is preceded by an initial frequency-modulated (iFM) component and followed by a terminal frequency-modulated (tFM) component. To examine the role of these components in echolocation, four bats were trained to fly from a perch to a landing bar. A dual camera system allowed reconstruction of the flight paths in three dimensions. Echolocation signals were recorded, analyzed, and correlated with the flight behavior of the bats. It was confirmed that during flight the bats compensate the Doppler shifts which are produced by their own flight movement. In free flight they emit per wing beat one single signal of long duration, with little variation in the three signal components. In approach flight the bats reduce pulse duration and interval with decreasing target range. The iFM is not varied with respect to target range, suggesting that this component plays little role in the processing of echolocating a target of interest. The bandwidth of the tFM component is increased while its duration is shortened in proportion to decreasing target range, so that the signal-echo overlap of the FM component is avoided down to a target distance of 15 cm. These concurrent changes suggest that the tFM component is used for ranging. During the last 60 cm of the approach the bats compensated for the increase of echo SPL by lowering the emission level of the CF component by 6-9 dB and that of the tFM component by 9-11 dB per halving of range. The specific signal structure of horseshoe bats is discussed as an adaptation for the hunting of fluttering insects in highly cluttered environments.

  9. Echolocation call intensity and directionality in flying short-tailed fruit bats, Carollia perspicillata (Phyllostomidae)

    DEFF Research Database (Denmark)

    Brinkløv, Signe; Jakobsen, Lasse; Ratcliffe, John M

    2011-01-01

    The directionality of bat echolocation calls defines the width of bats' sonar "view," while call intensity directly influences detection range since adequate sound energy must impinge upon objects to return audible echoes. Both are thus crucial parameters for understanding biosonar signal design....... a longer and narrower sonar range than previously thought. C. perspicillata orient and forage in the forest interior and the narrow beam might be adaptive in clutter, by reducing the number and intensity of off-axis echoes....

  10. Bat guilds, a concept to classify the highly diverse foraging and echolocation behaviors of microchiropteran bats

    Directory of Open Access Journals (Sweden)

    Annette eDenzinger

    2013-07-01

    Full Text Available Throughout evolution the foraging and echolocation behaviors as well as the motor systems of bats have been adapted to the tasks they have to perform while searching and acquiring food. When bats exploit the same class of environmental resources in a similar way, they perform comparable tasks and thus share similar adaptations independent of their phylogeny. Species with similar adaptations are assigned to guilds or functional groups. Habitat type and foraging mode mainly determine the foraging tasks and thus the adaptations of bats. Therefore we use habitat type and foraging mode to define seven guilds. The habitat types open, edge and narrow space are defined according to the bats’ echolocation behavior in relation to the distance between bat and background or food item and background. Bats foraging in the aerial, trawling, flutter detecting, or active gleaning mode use only echolocation to acquire their food. When foraging in the passive gleaning mode bats do not use echolocation but rely on sensory cues from the food item to find it. Bat communities often comprise large numbers of species with a high diversity in foraging areas, foraging modes, and diets. The assignment of species living under similar constraints into guilds identifies pattern of community structure and helps to understand the factors that underlie the organization of highly diverse bat communities. Bat species from different guilds do not compete for food as they differ in their foraging behavior and in the environmental resources they use. However, sympatric living species belonging to the same guild often exploit the same class of resources. To avoid competition they should differ in their niche dimensions. The fine grain structure of bat communities below the rather coarse classification into guilds is determined by mechanisms that result in niche partitioning.

  11. Global warming alters sound transmission: differential impact on the prey detection ability of echolocating bats

    Science.gov (United States)

    Luo, Jinhong; Koselj, Klemen; Zsebők, Sándor; Siemers, Björn M.; Goerlitz, Holger R.

    2014-01-01

    Climate change impacts the biogeography and phenology of plants and animals, yet the underlying mechanisms are little known. Here, we present a functional link between rising temperature and the prey detection ability of echolocating bats. The maximum distance for echo-based prey detection is physically determined by sound attenuation. Attenuation is more pronounced for high-frequency sound, such as echolocation, and is a nonlinear function of both call frequency and ambient temperature. Hence, the prey detection ability, and thus possibly the foraging efficiency, of echolocating bats and susceptible to rising temperatures through climate change. Using present-day climate data and projected temperature rises, we modelled this effect for the entire range of bat call frequencies and climate zones around the globe. We show that depending on call frequency, the prey detection volume of bats will either decrease or increase: species calling above a crossover frequency will lose and species emitting lower frequencies will gain prey detection volume, with crossover frequency and magnitude depending on the local climatic conditions. Within local species assemblages, this may cause a change in community composition. Global warming can thus directly affect the prey detection ability of individual bats and indirectly their interspecific interactions with competitors and prey. PMID:24335559

  12. Global warming alters sound transmission: differential impact on the prey detection ability of echolocating bats.

    Science.gov (United States)

    Luo, Jinhong; Koselj, Klemen; Zsebok, Sándor; Siemers, Björn M; Goerlitz, Holger R

    2014-02-06

    Climate change impacts the biogeography and phenology of plants and animals, yet the underlying mechanisms are little known. Here, we present a functional link between rising temperature and the prey detection ability of echolocating bats. The maximum distance for echo-based prey detection is physically determined by sound attenuation. Attenuation is more pronounced for high-frequency sound, such as echolocation, and is a nonlinear function of both call frequency and ambient temperature. Hence, the prey detection ability, and thus possibly the foraging efficiency, of echolocating bats and susceptible to rising temperatures through climate change. Using present-day climate data and projected temperature rises, we modelled this effect for the entire range of bat call frequencies and climate zones around the globe. We show that depending on call frequency, the prey detection volume of bats will either decrease or increase: species calling above a crossover frequency will lose and species emitting lower frequencies will gain prey detection volume, with crossover frequency and magnitude depending on the local climatic conditions. Within local species assemblages, this may cause a change in community composition. Global warming can thus directly affect the prey detection ability of individual bats and indirectly their interspecific interactions with competitors and prey.

  13. Hearing sensation levels of emitted biosonar clicks in an echolocating Atlantic bottlenose dolphin.

    Directory of Open Access Journals (Sweden)

    Songhai Li

    Full Text Available Emitted biosonar clicks and auditory evoked potential (AEP responses triggered by the clicks were synchronously recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus trained to wear suction-cup EEG electrodes and to detect targets by echolocation. Three targets with target strengths of -34, -28, and -22 dB were used at distances of 2 to 6.5 m for each target. The AEP responses were sorted according to the corresponding emitted click source levels in 5-dB bins and averaged within each bin to extract biosonar click-related AEPs from noise. The AEP amplitudes were measured peak-to-peak and plotted as a function of click source levels for each target type, distance, and target-present or target-absent condition. Hearing sensation levels of the biosonar clicks were evaluated by comparing the functions of the biosonar click-related AEP amplitude-versus-click source level to a function of external (in free field click-related AEP amplitude-versus-click sound pressure level. The results indicated that the dolphin's hearing sensation levels to her own biosonar clicks were equal to that of external clicks with sound pressure levels 16 to 36 dB lower than the biosonar click source levels, varying with target type, distance, and condition. These data may be assumed to indicate that the bottlenose dolphin possesses effective protection mechanisms to isolate the self-produced intense biosonar beam from the animal's ears during echolocation.

  14. Intense Ultrasonic clicks from echolocating toothed whales do not elicit anti-predator responses or debilitate the squid Loligo pealeii

    DEFF Research Database (Denmark)

    Wilson, Maria; Hanlon, Roger; Tyack, Peter

    2007-01-01

    an evolutionary selection pressure on cephalopods to develop a mechanism for detecting and evading sound-emitting toothed whale predators. Ultrasonic detection has evolved in some insects to avoid echolocating bats, and it can be hypothesized that cephalopods might have evolved similar ultrasound detection...... as an anti-predation measure. We test this hypothesis in the squid Loligo pealeii in a playback experiment using intense echolocation clicks from two squid-eating toothed whale species. Twelve squid were exposed to clicks at two repetition rates (16 and 125 clicks per second) with received sound pressure...... levels of 199-226dBre1μPa (pp) mimicking the sound exposure from an echolocating toothed whale as it approaches and captures prey. We demonstrate that intense ultrasonic clicks do not elicit any detectable anti-predator behaviour in L. pealeii and that clicks with received levels up to 226dBre1μPa (pp...

  15. Directionality of nose-emitted echolocation calls from bats without a nose-leaf (Plecotus auritus)

    DEFF Research Database (Denmark)

    Jakobsen, Lasse; Hallam, John; Moss, Cynthia F

    2018-01-01

    All echolocating bats and whales measured to date emit a directional bio-sonar beam that affords them a number of advantages over an omni-directional beam, i.e. reduced clutter, increased source level and inherent directional information. In this study we investigated the importance...... of a directional sound emission for navigation through echolocation by measuring the sonar beam of brown long-eared bats, Plecotus auritusP. auritus emits sound through the nostrils but has no external appendages to readily facility a directional sound emission as found in most nose emitters. The study shows...... that P. auritus, despite the lack of an external focusing apparatus, emits a directional echolocation beam (Directivity index=13 dB) and that the beam is more directional vertically (-6 dB angle at 22°) than horizontally (-6dB angle at 35°). Using a simple numerical model we find that the recorded...

  16. Biosonar adjustments to target range of echolocating bottlenose dolphins (Tursiops sp.) in the wild

    DEFF Research Database (Denmark)

    Jensen, Frants Havmand; Bejder, Lars; Wahlberg, Magnus

    2009-01-01

    Toothed whales use echolocation to locate and track prey. Most knowledge of toothed whale echolocation stems from studies on trained animals, and little is known about how toothed whales regulate and use their biosonar systems in the wild. Recent research suggests that an automatic gain control...... array echo. However, for interclick intervals longer than 30–40 ms, source levels were not limited by the repetition rate. Thus, pneumatic constraints in the sound-production apparatus cannot account for source level adjustments to range as a possible automatic gain control mechanism for target ranges...

  17. Following a Foraging Fish-Finder: Diel Habitat Use of Blainville's Beaked Whales Revealed by Echolocation

    Science.gov (United States)

    Arranz, Patricia; de Soto, Natacha Aguilar; Madsen, Peter T.; Brito, Alberto; Bordes, Fernando; Johnson, Mark P.

    2011-01-01

    Simultaneous high resolution sampling of predator behavior and habitat characteristics is often difficult to achieve despite its importance in understanding the foraging decisions and habitat use of predators. Here we tap into the biosonar system of Blainville's beaked whales, Mesoplodon densirostris, using sound and orientation recording tags to uncover prey-finding cues available to echolocating predators in the deep-sea. Echolocation sounds indicate where whales search and encounter prey, as well as the altitude of whales above the sea-floor and the density of organisms around them, providing a link between foraging activity and the bio-physical environment. Tagged whales (n = 9) hunted exclusively at depth, investing most of their search time either in the lower part of the deep scattering layer (DSL) or near the sea-floor with little diel change. At least 43% (420/974) of recorded prey-capture attempts were performed within the benthic boundary layer despite a wide range of dive depths, and many dives included both meso- and bentho-pelagic foraging. Blainville's beaked whales only initiate searching when already deep in the descent and encounter prey suitable for capture within 2 min of the start of echolocation, suggesting that these whales are accessing prey in reliable vertical strata. Moreover, these prey resources are sufficiently dense to feed the animals in what is effectively four hours of hunting per day enabling a strategy in which long dives to exploit numerous deep-prey with low nutritional value require protracted recovery periods (average 1.5 h) between dives. This apparent searching efficiency maybe aided by inhabiting steep undersea slopes with access to both the DSL and the sea-floor over small spatial scales. Aggregations of prey in these biotopes are located using biosonar-derived landmarks and represent stable and abundant resources for Blainville's beaked whales in the otherwise food-limited deep-ocean. PMID:22163295

  18. Following a foraging fish-finder: diel habitat use of Blainville's beaked whales revealed by echolocation.

    Directory of Open Access Journals (Sweden)

    Patricia Arranz

    Full Text Available Simultaneous high resolution sampling of predator behavior and habitat characteristics is often difficult to achieve despite its importance in understanding the foraging decisions and habitat use of predators. Here we tap into the biosonar system of Blainville's beaked whales, Mesoplodon densirostris, using sound and orientation recording tags to uncover prey-finding cues available to echolocating predators in the deep-sea. Echolocation sounds indicate where whales search and encounter prey, as well as the altitude of whales above the sea-floor and the density of organisms around them, providing a link between foraging activity and the bio-physical environment. Tagged whales (n = 9 hunted exclusively at depth, investing most of their search time either in the lower part of the deep scattering layer (DSL or near the sea-floor with little diel change. At least 43% (420/974 of recorded prey-capture attempts were performed within the benthic boundary layer despite a wide range of dive depths, and many dives included both meso- and bentho-pelagic foraging. Blainville's beaked whales only initiate searching when already deep in the descent and encounter prey suitable for capture within 2 min of the start of echolocation, suggesting that these whales are accessing prey in reliable vertical strata. Moreover, these prey resources are sufficiently dense to feed the animals in what is effectively four hours of hunting per day enabling a strategy in which long dives to exploit numerous deep-prey with low nutritional value require protracted recovery periods (average 1.5 h between dives. This apparent searching efficiency maybe aided by inhabiting steep undersea slopes with access to both the DSL and the sea-floor over small spatial scales. Aggregations of prey in these biotopes are located using biosonar-derived landmarks and represent stable and abundant resources for Blainville's beaked whales in the otherwise food-limited deep-ocean.

  19. Sensory trait variation in an echolocating bat suggests roles for both selection and plasticity

    Science.gov (United States)

    2014-01-01

    Background Across heterogeneous environments selection and gene flow interact to influence the rate and extent of adaptive trait evolution. This complex relationship is further influenced by the rarely considered role of phenotypic plasticity in the evolution of adaptive population variation. Plasticity can be adaptive if it promotes colonization and survival in novel environments and in doing so may increase the potential for future population differentiation via selection. Gene flow between selectively divergent environments may favour the evolution of phenotypic plasticity or conversely, plasticity itself may promote gene flow, leading to a pattern of trait differentiation in the presence of gene flow. Variation in sensory traits is particularly informative in testing the role of environment in trait and population differentiation. Here we test the hypothesis of ‘adaptive differentiation with minimal gene flow’ in resting echolocation frequencies (RF) of Cape horseshoe bats (Rhinolophus capensis) across a gradient of increasingly cluttered habitats. Results Our analysis reveals a geographically structured pattern of increasing RF from open to highly cluttered habitats in R. capensis; however genetic drift appears to be a minor player in the processes influencing this pattern. Although Bayesian analysis of population structure uncovered a number of spatially defined mitochondrial groups and coalescent methods revealed regional-scale gene flow, phylogenetic analysis of mitochondrial sequences did not correlate with RF differentiation. Instead, habitat discontinuities between biomes, and not genetic and geographic distances, best explained echolocation variation in this species. We argue that both selection for increased detection distance in relatively less cluttered habitats and adaptive phenotypic plasticity may have influenced the evolution of matched echolocation frequencies and habitats across different populations. Conclusions Our study reveals

  20. Echolocation behavior of big brown bats, Eptesicus fuscus, in the field and the laboratory

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Moss, Cynthia F.

    2000-01-01

    Echolocation signals were recorded from big brown bats, Eptesicus fuscus, flying in the field and the laboratory. In open field areas the interpulse intervals ~IPI! of search signals were either around 134 ms or twice that value, 270 ms. At long IPI’s the signals were of long duration ~14 to 18......–20 ms!, narrow bandwidth, and low frequency, sweeping down to a minimum frequency (Fmin) of 22–25 kHz. At short IPI’s the signals were shorter ~6–13 ms!, of higher frequency, and broader bandwidth. In wooded areas only short ~6–11 ms! relatively broadband search signals were emitted at a higher rate...

  1. Recording animal vocalizations from a UAV: bat echolocation during roost re-entry.

    Science.gov (United States)

    Kloepper, Laura N; Kinniry, Morgan

    2018-05-17

    Unmanned aerial vehicles (UAVs) are rising in popularity for wildlife monitoring, but direct recordings of animal vocalizations have not yet been accomplished, likely due to the noise generated by the UAV. Echolocating bats, especially Tadarida brasiliensis, are good candidates for UAV recording due to their high-speed, high-altitude flight. Here, we use a UAV to record the signals of bats during morning roost re-entry. We designed a UAV to block the noise of the propellers from the receiving microphone, and report on the characteristics of bioacoustic recordings from a UAV. We report the first published characteristics of echolocation signals from bats during group flight and cave re-entry. We found changes in inter-individual time-frequency shape, suggesting that bats may use differences in call design when sensing in complex groups. Furthermore, our first documented successful recordings of animals in their natural habitat demonstrate that UAVs can be important tools for bioacoustic monitoring, and we discuss the ethical considerations for such monitoring.

  2. The echolocation transmission beam of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis).

    Science.gov (United States)

    Fang, Liang; Wu, Yuping; Wang, Kexiong; Pine, Matthew K; Wang, Ding; Li, Songhai

    2017-08-01

    While the transmission beam of odontocetes has been described in a number of studies, the majority of them that have measured the transmission beam in two dimensions were focused on captive animals. Within the current study, a dedicated cross hydrophone array with nine elements was used to investigate the echolocation transmission beam of free-ranging Indo-Pacific humpback dolphins. A total of 265 on-axis clicks were analyzed, from which the apparent peak to peak source levels ranged between 168 to 207 dB (mean 184.5 dB ± 6.6 dB). The 3-dB beam width along the horizontal and vertical plane was 9.6° and 7.4°, respectively. Measured separately, the directivity index of the horizontal and vertical plane was 12.6 and 13.5 dB, respectively, and the overall directivity index (both planes combined) was 29.5 dB. The beam shape was slightly asymmetrical along the horizontal and vertical axis. Compared to other species, the characteristics of the transmitting beam of Indo-Pacific humpback dolphins were relatively close to the bottlenose dolphin (Tursiops truncatus), likely due to the similarity in the peak frequency and waveform of echolocation clicks and comparable body sizes of the two species.

  3. Human listening studies reveal insights into object features extracted by echolocating dolphins

    Science.gov (United States)

    Delong, Caroline M.; Au, Whitlow W. L.; Roitblat, Herbert L.

    2004-05-01

    Echolocating dolphins extract object feature information from the acoustic parameters of object echoes. However, little is known about which object features are salient to dolphins or how they extract those features. To gain insight into how dolphins might be extracting feature information, human listeners were presented with echoes from objects used in a dolphin echoic-visual cross-modal matching task. Human participants performed a task similar to the one the dolphin had performed; however, echoic samples consisting of 23-echo trains were presented via headphones. The participants listened to the echoic sample and then visually selected the correct object from among three alternatives. The participants performed as well as or better than the dolphin (M=88.0% correct), and reported using a combination of acoustic cues to extract object features (e.g., loudness, pitch, timbre). Participants frequently reported using the pattern of aural changes in the echoes across the echo train to identify the shape and structure of the objects (e.g., peaks in loudness or pitch). It is likely that dolphins also attend to the pattern of changes across echoes as objects are echolocated from different angles.

  4. The Acuity of Echolocation: Spatial Resolution in Sighted Persons Compared to the Performance of an Expert Who Is Blind

    Science.gov (United States)

    Teng, Santani; Whitney, David

    2011-01-01

    Echolocation is a specialized application of spatial hearing that uses reflected auditory information to localize objects and represent the external environment. Although it has been documented extensively in nonhuman species, such as bats and dolphins, its use by some persons who are blind as a navigation and object-identification aid has…

  5. Bats (Mammalia: Chiroptera) of the Eastern Mediterranean and Middle East. Part 8. Bats of Jordan: fauna, ecology, echolocation, ectoparasites

    Czech Academy of Sciences Publication Activity Database

    Benda, P.; Lučan, R. K.; Obuch, J.; Reiter, A.; Andreas, M.; Bačkor, P.; Bohnenstengel, T.; Eid, E. K.; Ševčík, M.; Vallo, Peter; Amr, Z. S.

    2010-01-01

    Roč. 74, 3-4 (2010), s. 185-353 ISSN 1211-376X Institutional research plan: CEZ:AV0Z60930519 Keywords : bats * distribution * ecology * echolocation * ectoparasites * Middle East * Jordan * Arabia * Palaearctic Region Subject RIV: EG - Zoology

  6. Acoustic scanning of natural scenes by echolocation in the big brown bat, Eptesicus fuscus

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Ghose, Kaushik; Moss, Cynthia F

    2009-01-01

    Echolocation allows bats to orient and localize prey in complete darkness. The sonar beam of the big brown bat, Eptesicus fuscus, is directional but broad enough to provide audible echo information from within a 60-90 deg. cone. This suggests that the big brown bat could interrogate a natural scene...

  7. Prey-capture success revealed by echolocation signals in pipistrelle bats (Pipistrellus pygmaeus)

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Futtrup, Vibeke; Tougaard, Jakob

    2003-01-01

    Three Pipistrellus pygmaeus bats were trained to capture prey on the wing while flying in the laboratory. The bats' capture behaviour and capture success were determined and correlated with acoustic analyses of post-buzz echolocation signals. Three acoustic parameters revealed capture success: in...

  8. Enhanced echolocation via robust statistics and super-resolution of sonar images

    Science.gov (United States)

    Kim, Kio

    Echolocation is a process in which an animal uses acoustic signals to exchange information with environments. In a recent study, Neretti et al. have shown that the use of robust statistics can significantly improve the resiliency of echolocation against noise and enhance its accuracy by suppressing the development of sidelobes in the processing of an echo signal. In this research, the use of robust statistics is extended to problems in underwater explorations. The dissertation consists of two parts. Part I describes how robust statistics can enhance the identification of target objects, which in this case are cylindrical containers filled with four different liquids. Particularly, this work employs a variation of an existing robust estimator called an L-estimator, which was first suggested by Koenker and Bassett. As pointed out by Au et al.; a 'highlight interval' is an important feature, and it is closely related with many other important features that are known to be crucial for dolphin echolocation. A varied L-estimator described in this text is used to enhance the detection of highlight intervals, which eventually leads to a successful classification of echo signals. Part II extends the problem into 2 dimensions. Thanks to the advances in material and computer technology, various sonar imaging modalities are available on the market. By registering acoustic images from such video sequences, one can extract more information on the region of interest. Computer vision and image processing allowed application of robust statistics to the acoustic images produced by forward looking sonar systems, such as Dual-frequency Identification Sonar and ProViewer. The first use of robust statistics for sonar image enhancement in this text is in image registration. Random Sampling Consensus (RANSAC) is widely used for image registration. The registration algorithm using RANSAC is optimized for sonar image registration, and the performance is studied. The second use of robust

  9. Analog VLSI Models of Range-Tuned Neurons in the Bat Echolocation System

    Directory of Open Access Journals (Sweden)

    Horiuchi Timothy

    2003-01-01

    Full Text Available Bat echolocation is a fascinating topic of research for both neuroscientists and engineers, due to the complex and extremely time-constrained nature of the problem and its potential for application to engineered systems. In the bat's brainstem and midbrain exist neural circuits that are sensitive to the specific difference in time between the outgoing sonar vocalization and the returning echo. While some of the details of the neural mechanisms are known to be species-specific, a basic model of reafference-triggered, postinhibitory rebound timing is reasonably well supported by available data. We have designed low-power, analog VLSI circuits to mimic this mechanism and have demonstrated range-dependent outputs for use in a real-time sonar system. These circuits are being used to implement range-dependent vocalization amplitude, vocalization rate, and closest target isolation.

  10. Divergent evolutionary rates in vertebrate and mammalian specific conserved non-coding elements (CNEs) in echolocating mammals.

    Science.gov (United States)

    Davies, Kalina T J; Tsagkogeorga, Georgia; Rossiter, Stephen J

    2014-12-19

    The majority of DNA contained within vertebrate genomes is non-coding, with a certain proportion of this thought to play regulatory roles during development. Conserved Non-coding Elements (CNEs) are an abundant group of putative regulatory sequences that are highly conserved across divergent groups and thus assumed to be under strong selective constraint. Many CNEs may contain regulatory factor binding sites, and their frequent spatial association with key developmental genes - such as those regulating sensory system development - suggests crucial roles in regulating gene expression and cellular patterning. Yet surprisingly little is known about the molecular evolution of CNEs across diverse mammalian taxa or their role in specific phenotypic adaptations. We examined 3,110 vertebrate-specific and ~82,000 mammalian-specific CNEs across 19 and 9 mammalian orders respectively, and tested for changes in the rate of evolution of CNEs located in the proximity of genes underlying the development or functioning of auditory systems. As we focused on CNEs putatively associated with genes underlying the development/functioning of auditory systems, we incorporated echolocating taxa in our dataset because of their highly specialised and derived auditory systems. Phylogenetic reconstructions of concatenated CNEs broadly recovered accepted mammal relationships despite high levels of sequence conservation. We found that CNE substitution rates were highest in rodents and lowest in primates, consistent with previous findings. Comparisons of CNE substitution rates from several genomic regions containing genes linked to auditory system development and hearing revealed differences between echolocating and non-echolocating taxa. Wider taxonomic sampling of four CNEs associated with the homeobox genes Hmx2 and Hmx3 - which are required for inner ear development - revealed family-wise variation across diverse bat species. Specifically within one family of echolocating bats that utilise

  11. Tongue-driven sonar beam steering by a lingual-echolocating fruit bat.

    Directory of Open Access Journals (Sweden)

    Wu-Jung Lee

    2017-12-01

    Full Text Available Animals enhance sensory acquisition from a specific direction by movements of head, ears, or eyes. As active sensing animals, echolocating bats also aim their directional sonar beam to selectively "illuminate" a confined volume of space, facilitating efficient information processing by reducing echo interference and clutter. Such sonar beam control is generally achieved by head movements or shape changes of the sound-emitting mouth or nose. However, lingual-echolocating Egyptian fruit bats, Rousettus aegyptiacus, which produce sound by clicking their tongue, can dramatically change beam direction at very short temporal intervals without visible morphological changes. The mechanism supporting this capability has remained a mystery. Here, we measured signals from free-flying Egyptian fruit bats and discovered a systematic angular sweep of beam focus across increasing frequency. This unusual signal structure has not been observed in other animals and cannot be explained by the conventional and widely-used "piston model" that describes the emission pattern of other bat species. Through modeling, we show that the observed beam features can be captured by an array of tongue-driven sound sources located along the side of the mouth, and that the sonar beam direction can be steered parsimoniously by inducing changes to the pattern of phase differences through moving tongue location. The effects are broadly similar to those found in a phased array-an engineering design widely found in human-made sonar systems that enables beam direction changes without changes in the physical transducer assembly. Our study reveals an intriguing parallel between biology and human engineering in solving problems in fundamentally similar ways.

  12. [Dietary composition, echolocation pulses and morphological measurements of the long-fingered bat Miniopterus fuliginosus (Chiroptera: Vespertilioninae)].

    Science.gov (United States)

    Hu, Kai-Liang; Wei, Li; Zhu, Teng-Teng; Wang, Xu-Zhong; Zhang, Li-Biao

    2011-04-01

    We investigated food (insect) availability in foraging areas utilized by the long-fingered bat Miniopterus fuliginosus using light traps, fish netting and fecal analysis. The dominant preys of M. fuliginosus were Lepidoptera (55%, by volume percent) and Coleoptera (38%) of a relatively large body size. M. fuliginosus has relatively long, narrow wings and a wing span of 6.58+/-0.12 and high wing loading of 9.85+/-0.83 N/m2. The echolocation calls of free flying M. fuliginosus were FM signals, with a pulse duration of 1.45+/-0.06 ms, interpulse interval of 63.08+/-21.55 ms, and low dominant frequency of 44.50+/-2.26 kHz. This study shows that the morphological characteristics and echolocation calls of long-fingered bats are closely linked to their predatory behavior.

  13. Variability in echolocation call intensity in a community of horseshoe bats: a role for resource partitioning or communication?

    Science.gov (United States)

    Schuchmann, Maike; Siemers, Björn M

    2010-09-17

    Only recently data on bat echolocation call intensities is starting to accumulate. Yet, intensity is an ecologically crucial parameter, as it determines the extent of the bats' perceptual space and, specifically, prey detection distance. Interspecifically, we thus asked whether sympatric, congeneric bat species differ in call intensities and whether differences play a role for niche differentiation. Specifically, we investigated whether R. mehelyi that calls at a frequency clearly above what is predicted by allometry, compensates for frequency-dependent loss in detection distance by using elevated call intensity. Maximum echolocation call intensities might depend on body size or condition and thus be used as an honest signal of quality for intraspecific communication. We for the first time investigated whether a size-intensity relation is present in echolocating bats. We measured maximum call intensities and frequencies for all five European horseshoe bat species. Maximum intensity differed among species largely due to R. euryale. Furthermore, we found no compensation for frequency-dependent loss in detection distance in R. mehelyi. Intraspecifically, there is a negative correlation between forearm lengths and intensity in R. euryale and a trend for a negative correlation between body condition index and intensity in R. ferrumequinum. In R. hipposideros, females had 8 dB higher intensities than males. There were no correlations with body size or sex differences and intensity for the other species. Based on call intensity and frequency measurements, we estimated echolocation ranges for our study community. These suggest that intensity differences result in different prey detection distances and thus likely play some role for resource access. It is interesting and at first glance counter-intuitive that, where a correlation was found, smaller bats called louder than large individuals. Such negative relationship between size or condition and vocal amplitude may

  14. Echolocating bats use a nearly time-optimal strategy to intercept prey.

    Directory of Open Access Journals (Sweden)

    Kaushik Ghose

    2006-05-01

    Full Text Available Acquisition of food in many animal species depends on the pursuit and capture of moving prey. Among modern humans, the pursuit and interception of moving targets plays a central role in a variety of sports, such as tennis, football, Frisbee, and baseball. Studies of target pursuit in animals, ranging from dragonflies to fish and dogs to humans, have suggested that they all use a constant bearing (CB strategy to pursue prey or other moving targets. CB is best known as the interception strategy employed by baseball outfielders to catch ballistic fly balls. CB is a time-optimal solution to catch targets moving along a straight line, or in a predictable fashion--such as a ballistic baseball, or a piece of food sinking in water. Many animals, however, have to capture prey that may make evasive and unpredictable maneuvers. Is CB an optimum solution to pursuing erratically moving targets? Do animals faced with such erratic prey also use CB? In this paper, we address these questions by studying prey capture in an insectivorous echolocating bat. Echolocating bats rely on sonar to pursue and capture flying insects. The bat's prey may emerge from foliage for a brief time, fly in erratic three-dimensional paths before returning to cover. Bats typically take less than one second to detect, localize and capture such insects. We used high speed stereo infra-red videography to study the three dimensional flight paths of the big brown bat, Eptesicus fuscus, as it chased erratically moving insects in a dark laboratory flight room. We quantified the bat's complex pursuit trajectories using a simple delay differential equation. Our analysis of the pursuit trajectories suggests that bats use a constant absolute target direction strategy during pursuit. We show mathematically that, unlike CB, this approach minimizes the time it takes for a pursuer to intercept an unpredictably moving target. Interestingly, the bat's behavior is similar to the interception strategy

  15. Echolocating bats use a nearly time-optimal strategy to intercept prey.

    Science.gov (United States)

    Ghose, Kaushik; Horiuchi, Timothy K; Krishnaprasad, P S; Moss, Cynthia F

    2006-05-01

    Acquisition of food in many animal species depends on the pursuit and capture of moving prey. Among modern humans, the pursuit and interception of moving targets plays a central role in a variety of sports, such as tennis, football, Frisbee, and baseball. Studies of target pursuit in animals, ranging from dragonflies to fish and dogs to humans, have suggested that they all use a constant bearing (CB) strategy to pursue prey or other moving targets. CB is best known as the interception strategy employed by baseball outfielders to catch ballistic fly balls. CB is a time-optimal solution to catch targets moving along a straight line, or in a predictable fashion--such as a ballistic baseball, or a piece of food sinking in water. Many animals, however, have to capture prey that may make evasive and unpredictable maneuvers. Is CB an optimum solution to pursuing erratically moving targets? Do animals faced with such erratic prey also use CB? In this paper, we address these questions by studying prey capture in an insectivorous echolocating bat. Echolocating bats rely on sonar to pursue and capture flying insects. The bat's prey may emerge from foliage for a brief time, fly in erratic three-dimensional paths before returning to cover. Bats typically take less than one second to detect, localize and capture such insects. We used high speed stereo infra-red videography to study the three dimensional flight paths of the big brown bat, Eptesicus fuscus, as it chased erratically moving insects in a dark laboratory flight room. We quantified the bat's complex pursuit trajectories using a simple delay differential equation. Our analysis of the pursuit trajectories suggests that bats use a constant absolute target direction strategy during pursuit. We show mathematically that, unlike CB, this approach minimizes the time it takes for a pursuer to intercept an unpredictably moving target. Interestingly, the bat's behavior is similar to the interception strategy implemented in some

  16. The Impact of Financial Crisis on the Transactions in Off-Shore Zones

    OpenAIRE

    Ispas Roxana

    2013-01-01

    In the following paper we have started from the premises that in the “money-wash” phenomenon analysis, the resulted money circulate in the entire world, through some geographic and institutional channels. Starting from the fiscal paradise characteristics we have accomplished a parallel between that and the financial paradise characteristics. In the second part of the paper, we have analyzed the offshore zones, showing also the methods of income placement in the respective countries with some ...

  17. Reliable, Lightweight Transmissions For Off-Shore, Utility Scale Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Jean-Claude Ossyra

    2012-10-25

    The objective of this project was to reduce the technical risk for a hydrostatic transmission based drivetrain for high-power utility-size wind turbines. A theoretical study has been performed to validate the reduction of cost of energy (CoE) for the wind turbine, identify risk mitigation strategies for the drive system and critical components, namely the pump, shaft connection and hydrostatic transmission (HST) controls and address additional benefits such as reduced deployment costs, improved torque density and improved mean time between repairs (MTBR).

  18. Mastering Electro-Mechanical Dynamics of Large Off-Shore Direct-Drive Wind Turbine Generators

    OpenAIRE

    Kirschneck, M.

    2016-01-01

    The ever growing population of human beings on earth introduces the challenge of providing affordable, sustainable energy for everyone. Emerging markets, such as China, India or Brazil, quench their thirst for cheap energy by fossil fuels and nuclear power. At the same time researchers from all over the globe warn the public of the advent of a new, civilisation threatening disaster: climate change. Over the last two centuries mankind has gotten used to cheap but polluting energy provided by b...

  19. Evaluating potentials for future generation off-shore wind-power outside Norway

    Science.gov (United States)

    Benestad, R. E.; Haugen, J.; Haakenstad, H.

    2012-12-01

    With todays critical need of renewable energy sources, it is naturally to look towards wind power. With the long coast of Norway, there is a large potential for wind farms offshore Norway. Although there are more challenges with offshore wind energy installations compared to wind farms on land, the offshore wind is generally higher, and there is also higher persistence of wind speed values in the power generating classes. I planning offshore wind farms, there is a need of evaluation of the wind resources, the wind climatology and possible future changes. In this aspect, we use data from regional climate model runs performed in the European ENSEMBLE-project (van der Linden and J.F.B. Mitchell, 2009). In spite of increased reliability in RCMs in the recent years, the simulations still suffer from systematic model errors, therefore the data has to be corrected before using them in wind resource analyses. In correcting the wind speeds from the RCMs, we will use wind speeds from a Norwegian high resolution wind- and wave- archive, NORA10 (Reistad et al 2010), to do quantile mapping (Themeβl et. al. 2012). The quantile mapping is performed individually for each regional simulation driven by ERA40-reanalysis from the ENSEMBLE-project corrected against NORA10. The same calibration is then used to the belonging regional climate scenario. The calibration is done for each grid cell in the domain and for each day of the year centered in a +/-15 day window to make an empirical cumulative density function for each day of the year. The quantile mapping of the scenarios provide us with a new wind speed data set for the future, more correct compared to the raw ENSEMBLE scenarios. References: Reistad M., Ø. Breivik, H. Haakenstad, O. J. Aarnes, B. R. Furevik and J-R Bidlo, 2010, A high-resolution hindcast of wind and waves for The North Sea, The Norwegian Sea and The Barents Sea. J. Geophys. Res., 116. doi:10.1029/2010JC006402. Themessl M. J., A. Gobiet and A. Leuprecht, 2012, Empirical-statistical downscaling and error correction of regional climate models and its imipact on the climate change signal. Climatic Change 112: 449-468, DOI 10.1007/s10584-011-0224-4. Van der Linden P. and J.F.B. Mitchell, 2009, ENSEMBLES: Climate Change and its Impacts_ Summary and results from the ENSEMBLES project. Met Office Hadley Centre, FitzRoy Road, Exeter EX1 3PB, UK.

  20. Hearing protector fit testing with off-shore oil-rig inspectors in Louisiana and Texas.

    Science.gov (United States)

    Murphy, William J; Themann, Christa L; Murata, Taichi K

    2016-11-01

    This field study aimed to assess the noise reduction of hearing protection for individual workers, demonstrate the effectiveness of training on the level of protection achieved, and measure the time required to implement hearing protector fit testing in the workplace. The National Institute for Occupational Safety and Health (NIOSH) conducted field studies in Louisiana and Texas to test the performance of HPD Well-Fit. Fit tests were performed on 126 inspectors and engineers working in the offshore oil industry. Workers were fit tested with the goal of achieving a 25-dB PAR. Less than half of the workers were achieving sufficient protection from their hearing protectors prior to NIOSH intervention and training; following re-fitting and re-training, over 85% of the workers achieved sufficient protection. Typical test times were 6-12 minutes. Fit testing of the workers' earplugs identified those workers who were and were not achieving the desired level of protection. Recommendations for other hearing protection solutions were made for workers who could not achieve the target PAR. The study demonstrates the need for individual hearing protector fit testing and addresses some of the barriers to implementation.

  1. The determinants of outsourcing and off-shoring strategies in industrial districts: evidence from Italy

    NARCIS (Netherlands)

    Capasso, M.; Cusmano, L.; Morrison, A.

    2013-01-01

    The determinants of outsourcing and offshoring strategies in industrial districts: evidence from Italy, Regional Studies. Outsourcing has increasingly become a distinguished feature of the recent evolution of industrial districts and it constitutes the object of this study. The study focuses on

  2. Outsourcing Maintenance Operations to Off-Shore Vendors: Some Lessons from the Field

    OpenAIRE

    Sam Ramanujan; Hal Lou

    1997-01-01

    Ever since Eastman Kodak announced that it was outsourcing its information systems (IS) function in 1988 to IBM, DEC and Businessland, large companies have found it acceptable to transfer their IS assets, leases and staff to third party vendors. In the recent past, there is a trend towards selective sourcing in which organizations opt to use third party vendors for certain IS functions which represent 20-60% of the IS budget while still retaining a substantial internal IS department. This pap...

  3. Development of natural seabed forms and their interaction with off shore wind farms

    DEFF Research Database (Denmark)

    Margalit, Jonatan

    and stone for use in construction. Elevated bedforms and reefs are also attractive in the construction of offshore wind farms. The formation of large, sandy bedforms on the sea floor has been studied in the past using linear stability analyses. These analyses are commonly conducted analytically...... and therefore require simplifications in the governing equations. This thesis presents a two-dimensional horizontal Matlab model that can simulate the morphodynamics of large-scale bedforms. The model was used to conduct a numerical linear stability analysis, intended to identify the likely emergence...... of dominant finite sized bedforms, as a function of governing parameters. The model includes separate formulations for bed load, featuring bed load correction due to a sloping bed and modeled helical flow effects as well as suspended load in a pseudo-3D description. Horizontal gradients are computed...

  4. Mastering Electro-Mechanical Dynamics of Large Off-Shore Direct-Drive Wind Turbine Generators

    NARCIS (Netherlands)

    Kirschneck, M.

    2016-01-01

    The ever growing population of human beings on earth introduces the challenge of providing affordable, sustainable energy for everyone. Emerging markets, such as China, India or Brazil, quench their thirst for cheap energy by fossil fuels and nuclear power. At the same time researchers from all over

  5. Setting the frame for up-scaled off-shore wind turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Chaviaropoulos, T.; Jamieson, P.

    2009-01-01

    are described in the paper. In the crude, deterministic formulation generic models for the costs are formulated as function of the design parameters and using basic up-scaling laws adjusted for technology improvement effects. The optimal design is obtained as the design which minimises the total expected costs...

  6. Using Learning Sets to Support UK Delivery of Off-Shore Learning in Africa

    Science.gov (United States)

    Blackburn, Michelle

    2014-01-01

    This account of practice focuses on the delivery of Action Learning Sets in Swaziland and Malawi as part of a UK university's remote Master's degree teaching programme. It draws upon the experience of an Academic delivering the programme and the efforts made to refine the approach to action learning given time, understanding and resource…

  7. The need for integrated off-shore, real-time information and management systems

    Energy Technology Data Exchange (ETDEWEB)

    Morley, L W

    1981-07-01

    Integrated planning, in which data from ships, aircraft, data buoys, and shore or satellite-borne radar are used for ocean surveillance is urged. The Atlantic coast of Canada is used as an example of the inefficiency of current management methods. Traffic control, search and rescue missions, pollution control, weather forecasting, and fisheries management are directed by separate government agencies, each with its own information system. A coordinated approach would reduce waste and allow full advantage to be taken of technological developments, e.g., satellites, unknown when the agencies were created.

  8. Off Shore wind energy – Case study of cooperation mechanisms design

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik; Hansen, Lise-Lotte Pade; Jansen, Jaap

    2012-01-01

    This document reports activities and results of Task 3.3 of the Intelligent Energy Europe supported project RES4Less. This work is the initial analyses and survey of barriers for implementing cooperation mechanisms in the EU countries. This work builds on earlier Intelligent Energy Europe projects...... also shared and enriched by comments from other members of the RES4Less Team during internal meetings of the project....

  9. Off-shore wind power plant modelling precision and efficiency in electromagnetic transient simulation programs

    Energy Technology Data Exchange (ETDEWEB)

    Karaagac, U.; Saad, H.; Mahseredjian, J. [Ecole Polytechnique de Montreal, Montreal, QC (Canada); Jensen, S.; Cai, L. [REpower Systems AG, Hamburg (Germany)

    2012-07-01

    The large number of switching elements in the modular multilevel converter (MMC) is a challenging problem for modeling the MMC-HVDC systems in electromagnetic transient type (EMT-type) programs. The modeling complexity increases even further when MMC-HVDC systems are used to integrate offshore wind farms (OWFs) with power electronics based wind energy converters, such as doubly-fed induction generators (DFIGs). This paper compares the computational performances of various combinations of MMC-HVDC and OWF models. Practical onshore ac fault scenarios are simulated for an OWF composed of DFIG type wind turbines and connected to a practical ac grid through a point-to-point MMC-HVDC system. (orig.)

  10. Dynamic scour protection for off-shore wind turbine foundations. Edge scour tests and results

    Energy Technology Data Exchange (ETDEWEB)

    Kularatne, K.A.S.R.; Sumer, B.M.; Fredsoee, J.

    2002-07-01

    Sufficient protection cover for the foundation of offshore wind turbines is an essential part in maintaining the stability of the structure. In addition to the danger caused by the flow conditions existing in the sea, a sudden change in the bed topography would definitely cause a greater risk on the stability of a structure. A movement of a sand bank close to the structure could be one of the common examples of that kind. Therefore, the main objective of the present study is to investigate the scour process at the tip of a scour protection for an offshore wind turbine foundation under a steady uniform flow parallel to the structure, while a sand bank is moving close by. The physical model of a scour protection for an offshore wind turbine foundation, which forms basis for this report, was constructed in the 23m long, 2m wide and 0.5m deep steady flow fume of ISVA, Technical University of Denmark. The processes of scouring and settlement of stones mainly close to the tip of the protection layer were monitored under number of different flow and bottom conditions such as flow velocity (Shields parameter), slope of the sand bank, number of scour protection layers and different lateral slopes of the sand bank. All the tests were conducted under live-bed conditions. After 10 different tests, the following conclusions were reached: 1. Formation of horseshoe vortex in front of the scour protection layer and the contraction of streamlines due to the obstruction caused by the scour protection were identified as the major mechanisms of scour causing instability of stones, 2. When a lateral slope was present, on top of the two major mechanisms the scouring originated from the toe of the lateral slope too apparently propagated towards the joint between the sand bed and the scour protection, 3. The maximum scour depth normalized by the stone size (S/D) found increase with the Shields parameter but for higher values of Shields parameter it becomes pronounced, 4. The slope of the sand bank too shows a significant influence on the maximum settlement of stones and the increase of steepness of the slope considerably increases the maximum scour depth. The starvation of sand caused by the increase in steepness is identified as the most possible reason for the increase in settlements, 5. The maximum settlement of stones shows a comparatively milder variation with the number of scour protection layers, 6. The maximum settlement of stones normalized by the stone size is again found to be rather responsive to a lateral slope of the sand bank. More pronounced scouring instigated from the toe of the scour protection was apparent with the increase of the steepness of the lateral slope. (BA)

  11. Dynamics and control of multi-terminal HVDC systems for off-shore wind farm integration

    Energy Technology Data Exchange (ETDEWEB)

    Ciapessoni, E.; Cirio, D.; Gatti, A.; Pitto, A. [Ricerca sul Sistema Energetico SpA (RSE), Milan (Italy)

    2011-07-01

    This paper addresses dynamic modelling aspects concerning the operation of VSC-based MTDC networks connecting large offshore wind farms to mainland AC system. In particular, stability issues of the AC-DC system under severe contingencies such as AC fault on mainland side, DC cable faults, and loss of offshore VSC terminal are analysed, and possible stabilising controls are identified. The propose model includes the basic and control strategies for converters on mainland and offshore side, and an additional global control which simulates the action of SPS-Special Protection System. Simulations are performed on a test system implemented in DIgSILENT Power Factory platform, including the proposed control systems and detailed models of wind turbine DFIGs. The work has been carried out within the FP7 European research project ''TWENTIES''. (orig.)

  12. Exploration potential of the Eocene deposits in central Romanian block sea off shore

    International Nuclear Information System (INIS)

    Tambrea, D; Raileanu, A; Barbuliceanu, N; Borosi, V.

    2002-01-01

    Full text:The study area comprises the Eocene Istria Depression bounded by Peceneaga- Camena and Heracleea faults, in front of North Dobrogea Orogene and Central Dobrogea, in the Romanian Black Sea offshore. The analysis of 100 two- dimensional (2D) seismic lines and two- three dimensional (3D) seismic surveys and well data has permitted to outline that the geo dynamic evolution of Eocene basins has led to the deposition of carbonate- sliciclastic turbidity, porous carbonate shelf margin reservoir deposits, and muddy carbonate turbiditic source rocks that present new Eocene petroleum targets. The main Eocene sub basin located in Iris-Venus area is deep, rhombic shaped, del imitated by normal faults, and may be connected with the strike-slip deformation component of Peceneaga- Camena fault. The next sub basin, located on West Lebeda area may be considered a cross- fault extensional zone. In the following sub basin East Lebada- Minerva area, normal faults generated a tectonic corridor characterized by high subsidence rate and local submarine/sub aerial intra slope topographic high. The last sub basin localized in Histria is a ponded one and captured highly organic matter rich muddly carbonate turgidities. In all sub basins, there is a progression from structure control to sediment control deposition

  13. Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

    Science.gov (United States)

    André, M.; Caballé, A.; van der Schaar, M.; Solsona, A.; Houégnigan, L.; Zaugg, S.; Sánchez, A. M.; Castell, J. V.; Solé, M.; Vila, F.; Djokic, D.; Adrián-Martínez, S.; Albert, A.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; De Bonis, G.; Distefano, C.; Di Palma, I.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernandez-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Păvălaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zuñiga, J.

    2017-01-01

    Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to-shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystems. PMID:28401960

  14. Comparison of echolocation clicks from geographically sympatric killer whales and long-finned pilot whales

    DEFF Research Database (Denmark)

    Eskesen, Ida; Wahlberg, Magnus; Simon, Malene

    2010-01-01

    The source characteristics of biosonar signals from sympatric killer whales and long-finned pilot whales in a Norwegian fjord were compared. A total of 137 pilot whale and more than 2000 killer whale echolocation clicks were recorded using a linear four-hydrophone array. Of these, 20 pilot whale...... clicks and 28 killer whale clicks were categorized as being recorded on-axis. The clicks of pilot whales had a mean apparent source level of 196 dB re 1 lPa pp and those of killer whales 203 dB re 1 lPa pp. The duration of pilot whale clicks was significantly shorter (23 ls, S.E.¼1.3) and the centroid...... frequency significantly higher (55 kHz, S.E.¼2.1) than killer whale clicks (duration: 41 ls, S.E.¼2.6; centroid frequency: 32 kHz, S.E.¼1.5). The rate of increase in the accumulated energy as a function of time also differed between clicks from the two species. The differences in duration, frequency...

  15. Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

    Science.gov (United States)

    André, M.; Caballé, A.; van der Schaar, M.; Solsona, A.; Houégnigan, L.; Zaugg, S.; Sánchez, A. M.; Castell, J. V.; Solé, M.; Vila, F.; Djokic, D.; Adrián-Martínez, S.; Albert, A.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M. C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; de Bonis, G.; Distefano, C.; di Palma, I.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L. A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernandez-Rey, J. J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C. W.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J. A.; Mathieu, A.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Păvălaş, G. E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, Th.; Sánchez-Losa, A.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; van Elewyck, V.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J. D.; Zuñiga, J.

    2017-04-01

    Despite dedicated research has been carried out to adequately map the distribution of the sperm whale in the Mediterranean Sea, unlike other regions of the world, the species population status is still presently uncertain. The analysis of two years of continuous acoustic data provided by the ANTARES neutrino telescope revealed the year-round presence of sperm whales in the Ligurian Sea, probably associated with the availability of cephalopods in the region. The presence of the Ligurian Sea sperm whales was demonstrated through the real-time analysis of audio data streamed from a cabled-to-shore deep-sea observatory that allowed the hourly tracking of their long-range echolocation behaviour on the Internet. Interestingly, the same acoustic analysis indicated that the occurrence of surface shipping noise would apparently not condition the foraging behaviour of the sperm whale in the area, since shipping noise was almost always present when sperm whales were acoustically detected. The continuous presence of the sperm whale in the region confirms the ecological value of the Ligurian sea and the importance of ANTARES to help monitoring its ecosystems.

  16. Clicking in shallow rivers: short-range echolocation of Irrawaddy and Ganges River dolphins in a shallow, acoustically complex habitat.

    Directory of Open Access Journals (Sweden)

    Frants H Jensen

    Full Text Available Toothed whales (Cetacea, odontoceti use biosonar to navigate their environment and to find and catch prey. All studied toothed whale species have evolved highly directional, high-amplitude ultrasonic clicks suited for long-range echolocation of prey in open water. Little is known about the biosonar signals of toothed whale species inhabiting freshwater habitats such as endangered river dolphins. To address the evolutionary pressures shaping the echolocation signal parameters of non-marine toothed whales, we investigated the biosonar source parameters of Ganges river dolphins (Platanista gangetica gangetica and Irrawaddy dolphins (Orcaella brevirostris within the river systems of the Sundarban mangrove forest. Both Ganges and Irrawaddy dolphins produced echolocation clicks with a high repetition rate and low source level compared to marine species. Irrawaddy dolphins, inhabiting coastal and riverine habitats, produced a mean source level of 195 dB (max 203 dB re 1 µPapp whereas Ganges river dolphins, living exclusively upriver, produced a mean source level of 184 dB (max 191 re 1 µPapp. These source levels are 1-2 orders of magnitude lower than those of similar sized marine delphinids and may reflect an adaptation to a shallow, acoustically complex freshwater habitat with high reverberation and acoustic clutter. The centroid frequency of Ganges river dolphin clicks are an octave lower than predicted from scaling, but with an estimated beamwidth comparable to that of porpoises. The unique bony maxillary crests found in the Platanista forehead may help achieve a higher directionality than expected using clicks nearly an octave lower than similar sized odontocetes.

  17. Light-emitting diode street lights reduce last-ditch evasive manoeuvres by moths to bat echolocation calls

    Science.gov (United States)

    Wakefield, Andrew; Stone, Emma L.; Jones, Gareth; Harris, Stephen

    2015-01-01

    The light-emitting diode (LED) street light market is expanding globally, and it is important to understand how LED lights affect wildlife populations. We compared evasive flight responses of moths to bat echolocation calls experimentally under LED-lit and -unlit conditions. Significantly, fewer moths performed ‘powerdive’ flight manoeuvres in response to bat calls (feeding buzz sequences from Nyctalus spp.) under an LED street light than in the dark. LED street lights reduce the anti-predator behaviour of moths, shifting the balance in favour of their predators, aerial hawking bats. PMID:26361558

  18. Stimulation of the basal and central amygdala in the mustached bat triggers echolocation and agonistic vocalizations within multimodal output.

    Science.gov (United States)

    Ma, Jie; Kanwal, Jagmeet S

    2014-01-01

    The neural substrate for the perception of vocalizations is relatively well described, but how their timing and specificity are tightly coupled with accompanying physiological changes and context-appropriate behaviors remains unresolved. We hypothesized that temporally integrated vocal and emotive responses, especially the expression of fear, vigilance and aggression, originate within the amygdala. To test this hypothesis, we performed electrical microstimulation at 461 highly restricted loci within the basal and central amygdala in awake mustached bats. At a subset of these sites, high frequency stimulation with weak constant current pulses presented at near-threshold levels triggered vocalization of either echolocation pulses or social calls. At the vast majority of locations, microstimulation produced a constellation of changes in autonomic and somatomotor outputs. These changes included widespread co-activation of significant tachycardia and hyperventilation and/or rhythmic ear pinna movements (PMs). In a few locations, responses were constrained to vocalization and/or PMs despite increases in the intensity of stimulation. The probability of eliciting echolocation pulses vs. social calls decreased in a medial-posterior to anterolateral direction within the centrobasal amygdala. Microinjections of kainic acid (KA) at stimulation sites confirmed the contribution of cellular activity rather than fibers-of-passage in the control of multimodal outputs. The results suggest that localized clusters of neurons may simultaneously modulate the activity of multiple central pattern generators (CPGs) present within the brainstem.

  19. Stimulation of the Basal and Central Amygdala in the Mustached Bat Triggers Echolocation and Agonistic Vocalizations within Multimodal Output

    Directory of Open Access Journals (Sweden)

    Jie eMa

    2014-03-01

    Full Text Available The neural substrate for the perception of vocalization is relatively well described, but we know much less about how the timing and specificity of vocalizations is tightly coupled with audiovocal communication behavior. In many vocal species, well-timed vocalizations accompany fear, vigilance and aggression. These emotive responses likely originate within the amygdala and other limbic structures, but the organization of motor outputs for triggering species-appropriate behaviors remains unclear. We performed electrical microstimulation at 461 highly restricted loci within the basal and central amygdala in awake mustached bats. At a subset of these sites, high frequency stimulation with weak constant current pulses presented at near-threshold levels triggered vocalization of either echolocation pulses or social calls. At the vast majority of locations, microstimulation produced a constellation of changes in autonomic and somatomotor outputs. These changes included widespread co-activation of significant tachycardia and hyperventilation and/or rhythmic ear pinna movements. In a few locations, responses were constrained to vocalization and/or pinna movements despite increases in the intensity of stimulation. The probability of eliciting echolocation pulses versus social calls decreased in a medial-posterior to anterolateral direction within the centrobasal amygdala. Microinjections of kainic acid at stimulation sites confirmed the contribution of cellular activity rather than fibers-of-passage in the control of multimodal outputs. The results suggest that multimodal clusters of neurons may simultaneously modulate the activity of multiple central pattern generators present within the brainstem.

  20. Echolocation signals of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis) in Sanniang Bay, China.

    Science.gov (United States)

    Fang, Liang; Li, Songhai; Wang, Kexiong; Wang, Zhitao; Shi, Wenjing; Wang, Ding

    2015-09-01

    While the low-frequency communication sounds of Indo-Pacific humpback dolphins (Sousa chinensis) have been reported in a number of papers, the high-frequency echolocation signals of Sousa chinensis, especially those living in the wild, have been less studied. In the current study, echolocation signals of humpback dolphins were recorded in Sanniang Bay, Guangxi Province, China, using a cross-type hydrophone array with five elements. In total, 77 candidate on-axis clicks from 77 scans were selected for analysis. The results showed that the varied peak-to-peak source levels ranged from 177.1 to 207.3 dB, with an average of 187.7 dB re: 1 μPa. The mean peak frequency was 109.0 kHz with a -3-dB bandwidth of 50.3 kHz and 95% energy duration of 22 μs. The -3-dB bandwidth was much broader than the root mean square bandwidth and exhibited a bimodal distribution. The center frequency exhibited a positive relationship with the peak-to-peak source level. The clicks of the wild Indo-Pacific humpback dolphins were short-duration, broadband, ultrasonic pulses, similar to those produced by other whistling dolphins of similar body size. However, the click source levels of the Indo-Pacific humpback dolphin appear to be lower than those of other whistling dolphins.

  1. Ship noise extends to frequencies used for echolocation by endangered killer whales

    Directory of Open Access Journals (Sweden)

    Scott Veirs

    2016-02-01

    standard deviations. This is the first study to present source spectra for populations of different ship classes operating in coastal habitats, including at higher frequencies used by killer whales for both communication and echolocation.

  2. Dynamic representation of 3D auditory space in the midbrain of the free-flying echolocating bat

    Science.gov (United States)

    2018-01-01

    Essential to spatial orientation in the natural environment is a dynamic representation of direction and distance to objects. Despite the importance of 3D spatial localization to parse objects in the environment and to guide movement, most neurophysiological investigations of sensory mapping have been limited to studies of restrained subjects, tested with 2D, artificial stimuli. Here, we show for the first time that sensory neurons in the midbrain superior colliculus (SC) of the free-flying echolocating bat encode 3D egocentric space, and that the bat’s inspection of objects in the physical environment sharpens tuning of single neurons, and shifts peak responses to represent closer distances. These findings emerged from wireless neural recordings in free-flying bats, in combination with an echo model that computes the animal’s instantaneous stimulus space. Our research reveals dynamic 3D space coding in a freely moving mammal engaged in a real-world navigation task. PMID:29633711

  3. Testing the Sensory Drive Hypothesis: Geographic variation in echolocation frequencies of Geoffroy's horseshoe bat (Rhinolophidae: Rhinolophus clivosus).

    Science.gov (United States)

    Jacobs, David S; Catto, Sarah; Mutumi, Gregory L; Finger, Nikita; Webala, Paul W

    2017-01-01

    Geographic variation in sensory traits is usually influenced by adaptive processes because these traits are involved in crucial life-history aspects including orientation, communication, lineage recognition and mate choice. Studying this variation can therefore provide insights into lineage diversification. According to the Sensory Drive Hypothesis, lineage diversification may be driven by adaptation of sensory systems to local environments. It predicts that acoustic signals vary in association with local climatic conditions so that atmospheric attenuation is minimized and transmission of the signals maximized. To test this prediction, we investigated the influence of climatic factors (specifically relative humidity and temperature) on geographic variation in the resting frequencies of the echolocation pulses of Geoffroy's horseshoe bat, Rhinolophus clivosus. If the evolution of phenotypic variation in this lineage tracks climate variation, human induced climate change may lead to decreases in detection volumes and a reduction in foraging efficiency. A complex non-linear interaction between relative humidity and temperature affects atmospheric attenuation of sound and principal components composed of these correlated variables were, therefore, used in a linear mixed effects model to assess their contribution to observed variation in resting frequencies. A principal component composed predominantly of mean annual temperature (factor loading of -0.8455) significantly explained a proportion of the variation in resting frequency across sites (P < 0.05). Specifically, at higher relative humidity (around 60%) prevalent across the distribution of R. clivosus, increasing temperature had a strong negative effect on resting frequency. Climatic factors thus strongly influence acoustic signal divergence in this lineage, supporting the prediction of the Sensory Drive Hypothesis. The predicted future increase in temperature due to climate change is likely to decrease the

  4. Testing the Sensory Drive Hypothesis: Geographic variation in echolocation frequencies of Geoffroy's horseshoe bat (Rhinolophidae: Rhinolophus clivosus.

    Directory of Open Access Journals (Sweden)

    David S Jacobs

    Full Text Available Geographic variation in sensory traits is usually influenced by adaptive processes because these traits are involved in crucial life-history aspects including orientation, communication, lineage recognition and mate choice. Studying this variation can therefore provide insights into lineage diversification. According to the Sensory Drive Hypothesis, lineage diversification may be driven by adaptation of sensory systems to local environments. It predicts that acoustic signals vary in association with local climatic conditions so that atmospheric attenuation is minimized and transmission of the signals maximized. To test this prediction, we investigated the influence of climatic factors (specifically relative humidity and temperature on geographic variation in the resting frequencies of the echolocation pulses of Geoffroy's horseshoe bat, Rhinolophus clivosus. If the evolution of phenotypic variation in this lineage tracks climate variation, human induced climate change may lead to decreases in detection volumes and a reduction in foraging efficiency. A complex non-linear interaction between relative humidity and temperature affects atmospheric attenuation of sound and principal components composed of these correlated variables were, therefore, used in a linear mixed effects model to assess their contribution to observed variation in resting frequencies. A principal component composed predominantly of mean annual temperature (factor loading of -0.8455 significantly explained a proportion of the variation in resting frequency across sites (P < 0.05. Specifically, at higher relative humidity (around 60% prevalent across the distribution of R. clivosus, increasing temperature had a strong negative effect on resting frequency. Climatic factors thus strongly influence acoustic signal divergence in this lineage, supporting the prediction of the Sensory Drive Hypothesis. The predicted future increase in temperature due to climate change is likely to

  5. Echolocation in the bat, Rhinolophus capensis: the influence of clutter, conspecifics and prey on call design and intensity

    Directory of Open Access Journals (Sweden)

    Kayleigh Fawcett

    2015-07-01

    Full Text Available Echolocating bats are exposed not only to the echoes of their own calls, but often the signals of conspecifics and other bats. For species emitting short, frequency modulated signals e.g. vespertilionoids, adjustments in both the frequency and time domain have been observed in such situations. However, bats using long duration, constant frequency calls may confront special challenges, since these bats should be less able to avoid temporal and frequency overlap. Here we investigated echolocation call design in the highduty cycle bat, Rhinolophus capensis, as bats flew with either a conspecific or heterospecific in a large outdoor flight-room. We compared these recordings to those made of bats flying alone in the same flight-room, and in a smaller flight room, alone, and hunting tethered moths. We found no differences in duty cycle or peak frequency of the calls of R. capensis across conditions. However, in the presence of a conspecific or the vespertilionoid, Miniopterus natalensis, R. capensis produced longer frequency-modulated downward sweeps at the terminus of their calls with lower minimum frequencies than when flying alone. In the presence of the larger high-duty cycle bat, R. clivosus, R. capensis produced shorter calls than when flying alone or with a conspecific. These changes are similar to those of vespertilionoids when flying from open to more cluttered environments. They are not similar to those differences observed in vespertilionoids when flying with other bats. Also unlike vespertilinoids, R. capensis used calls 15 dB less intense in conspecific pairs than when alone.

  6. Possible age-related hearing loss (presbycusis) and corresponding change in echolocation parameters in a stranded Indo-Pacific humpback dolphin.

    Science.gov (United States)

    Li, Songhai; Wang, Ding; Wang, Kexiong; Hoffmann-Kuhnt, Matthias; Fernando, Nimal; Taylor, Elizabeth A; Lin, Wenzhi; Chen, Jialin; Ng, Timothy

    2013-11-15

    The hearing and echolocation clicks of a stranded Indo-Pacific humpback dolphin (Sousa chinensis) in Zhuhai, China, were studied. This animal had been repeatedly observed in the wild before it was stranded and its age was estimated to be ~40 years. The animal's hearing was measured using a non-invasive auditory evoked potential (AEP) method. Echolocation clicks produced by the dolphin were recorded when the animal was freely swimming in a 7.5 m (width)×22 m (length)×4.8 m (structural depth) pool with a water depth of ~2.5 m. The hearing and echolocation clicks of the studied dolphin were compared with those of a conspecific younger individual, ~13 years of age. The results suggested that the cut-off frequency of the high-frequency hearing of the studied dolphin was ~30-40 kHz lower than that of the younger individual. The peak and centre frequencies of the clicks produced by the older dolphin were ~16 kHz lower than those of the clicks produced by the younger animal. Considering that the older dolphin was ~40 years old, its lower high-frequency hearing range with lower click peak and centre frequencies could probably be explained by age-related hearing loss (presbycusis).

  7. Sea pollution and civil responsibility at the off-shore activities in the petroleum industry; Poluicao marinha e responsabilidade civil nas atividades off-shore da industria do petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Holder, Julianne; Camara, Camila Gomes

    2011-01-15

    This work analyses the aspects which involve the responsibility of the polluter by spilling of hydrocarbon in sea environment, not only due to petroleum disasters occurred in the oceans, but also provenient of constant spillings coming from supplying, load ad discharge, routine operations at terminals and ports.

  8. Pre feasibility assesment of smart off shore NPP (ONPP) of gravity based-structure type for Indonesia

    International Nuclear Information System (INIS)

    Sahala M Lumbanraja; Dharu Dewi

    2017-01-01

    The SMART ONPP GBS-type is a small power (100 MWe) pressurized water reactor, and located at offshore site. This technology was developed based on existing SMART nuclear technology & offshore drilling technology with a gravity-based type of structure. This is a response to the post-Fukushima accident, Japan (2011), to improve the safety system, overcome the land limitations, and minimize the public resistance to NPP cases in the inland. The purpose of this paper is to assess the pre-feasibility of the implementation of GBS NPP in Indonesia both in terms of technological feasibility and regulation. The method used is literature review and continued with descriptive analysis. The result shows that SMART ONPP are worth considering because they offer improved aspects of safety, offshore tread availability, and better public acceptance. So far, this NPP can not be implemented in Indonesia because it is hampered by Government Regulation No. 2 year 2014 regarding Licensing of Nuclear Installation Safety and Security which stipulates that site is an inland location and NPP built in Indonesia should be proven. (author)

  9. Next generation self-shielded flux cored electrode with improved toughness for off shore oil well platform structures

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Daya; Soltis, Patrick; Narayanan, Badri; Quintana, Marie; Fox, Jeff [The Lincoln Electric Company (United States)

    2005-07-01

    Self-shielded flux cored arc welding electrodes (FCAW-S) are ideal for outdoor applications, particularly open fabrication yards where high winds are a possibility. Development work was carried out on a FCAW-S electrode for welding 70 and 80 ksi yield strength base materials with a required minimum average Charpy V-Notch (CVN) absorbed energy value of 35 ft-lb at -40 deg F in the weld metal. The effect of Al, Mg, Ti, and Zr on CVN toughness was evaluated by running a Design of Experiments approach to systematically vary the levels of these components in the electrode fill and, in turn, the weld metal. These electrodes were used to weld simulated pipe joints. Over the range of compositions tested, 0.05% Ti in the weld metal was found to be optimum for CVN toughness. Ti also had a beneficial effect on the usable voltage range. Simulated offshore joints were welded to evaluate the effect of base metal dilution, heat input, and welding procedure on the toughness of weld metal. CVN toughness was again measured at -40 deg F on samples taken from the root and the cap pass regions. The root pass impact toughness showed strong dependence on the base metal dilution and the heat input used to weld the root and fill passes. (author)

  10. Study of ecological consequence of the bloom (Noctiluca miliaris) in off shore waters of the Northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Dwivedi, R.M.; Chauhan, R.; Solanki, H.U.; Raman, M.; Matondkar, S.G.P.; Madhu, V.R.; Meenakumari, B.

    , NO. 4, AUGUST 2012 306 Schools of flying fishes and large size squids were observed during night at one bloom station in March 2007 (FORV-253). Also, on one occasion baby sharks were found swimming inside the bloom patch. These observations...

  11. Analysis of the coral associated bacterial community structures in healthy and diseased corals from off-shore of southern Taiwan.

    Science.gov (United States)

    Chiou, Shu-Fen; Kuo, Jimmy; Wong, Tit-Yee; Fan, Tung-Yung; Tew, Kwee Siong; Liu, Jong-Kang

    2010-07-01

    The methods of denaturing gradient gel electrophoresis (DGGE) and DNA sequencing were used to analyze the ribotypes of microbial communities associated with corals. Both healthy and diseased coral of different species were collected at three locations off the southern coast of Taiwan. Ribotyping results suggested that the microbial communities were diverse. The microbial community profiles, even among the same species of corals from different geographical locations, differ significantly. The coral-associated bacterial communities contain many bacteria common to the habitants of various invertebrates. However, some bacteria were unexpected. The presence of some unusual species, such as Staphylococcus, Clostridium and Legionella, associated with corals that were likely the results of human activities. Human activities, such as thermal pollution from the nearby nuclear plant, active fishing and tourism industries in the region might have all contributed to the change in bacterial communities and the death of coral colonies around the region.

  12. Volatility Transmission between Renminbi and Asia-Pacific on-shore and off-shore U.S. dollar futures

    OpenAIRE

    Michael Funke; Roberta Colavecchio

    2008-01-01

    This paper uses multivariate GARCH techniques to study volatility spillovers between the Chinese non-deliverable forward market and seven of its Asia-Pacific counterparts over the period January 1998 to March 2005. To account for the time-variability of conditional correlation, a dynamic correlation structure is included in the volatility model specification. The empirical results demonstrate that the renminbi non-deliverable forward (NDF) has been a driver of various Asian currency markets b...

  13. A comparative analysis of the environmental impacts of a Pelamis Wave Energy device with existing off shore developments and installations.

    OpenAIRE

    Quinn, Eoghan

    2011-01-01

    Scotland is currently at the forefront of development and expansion of wave energy, especially with recent renewable energy targets. Research and development has increased greatly off the Scottish coastline. Various adjectives can be used to describe wave energy’s creative potential in helping to achieve Scotland’s energy goals. Put simply however the production of wave energy appears to have all the ingredients for success; it is benign, the visual impacts minimal and its energy is reliable,...

  14. Off-shore enhanced oil recovery in the North Sea : The impact of price uncertainty on the investment decisions

    NARCIS (Netherlands)

    Compernolle, T.; K, Welkenhuysen,; Huisman, Kuno; K, Piessens,; Kort, Peter

    2017-01-01

    Although CO2 Capture and Storage (CCS) is considered a key solution for CO2 emission mitigation, it is currently not economically feasible. CO2 enhanced oil recovery can play a significant role in stimulating CCS deployment because CO2 is used to extract additional quantities of oil. This study

  15. Off-shore enhanced oil recovery in the North Sea: The impact of price uncertainty on the investment decisions

    International Nuclear Information System (INIS)

    Compernolle, T.; Welkenhuysen, K.; Huisman, K.; Piessens, K.; Kort, P.

    2017-01-01

    Although CO_2 Capture and Storage (CCS) is considered a key solution for CO_2 emission mitigation, it is currently not economically feasible. CO_2 enhanced oil recovery can play a significant role in stimulating CCS deployment because CO_2 is used to extract additional quantities of oil. This study analyzes the investment decision of both a carbon emitting source and an oil company separately by adopting a real options approach. It is shown that when uncertainty is integrated in the economic analysis, CO_2 and oil price threshold levels at which investments in CO_2 capture and enhanced oil recovery will take place, are higher than when a net present value approach is adopted. We also demonstrate that a tax on CO_2 instead of an emission trading system results in a lower investment threshold level for the investment in the CO_2 capture unit. Furthermore, we determine a minimum CO_2 selling price between the two firms and show that CO_2-EOR has the potential to pull CCS into the market by providing an additional revenue on the capture plant. However, when CO_2 permit prices are above an identifiable level, the EU ETS does not necessarily result in the adoption of CCS and stimulates oil production. - Highlights: • Real options theory is applied to study how uncertainty affects CO2EOR investments. • Compared to an NPV approach, investment threshold levels are higher. • A tax on CO2 would result in lower investment threshold levels compared to EUETS. • A minimum CO2 selling price is determined • The CO2 needed for enhanced oil recovery is not necessarily a cost.

  16. Off-shore contamination by I-131 and Cs-137 from the Fukushima Daiichi nuclear power station accident

    International Nuclear Information System (INIS)

    Pereira, Wagner de Souza; Kelecom, Patrick Vicent; Miyashita, Erika; Universidade Federal Fluminense; Kelecom, Alphonse

    2011-01-01

    On March 11, 2011 the biggest earthquake ever registered in Japan severed off-site power supply to the Fukushima Daiichi Nuclear Power Station. Backup diesel generators began providing electricity to pumps circulating coolant to the reactors, but were knocked out by a large tsunami and the nuclear site lost the ability to maintain proper reactor cooling. This was the beginning of a huge nuclear accident that was assigned an INES maximum rating of 7. On March 21, Japanese authorities reported that the Tokyo Electric Power Company (TEPCO) had detected radioactive materials in seawater. Radioactivity started to be measured by the Japan Atomic Energy Agency every two days in sea water from eight locations, 30km from the coastline. I-131 and Cs-137 were analyzed among other radionuclides. It is the aim of this paper to gather all this information and to discuss the evolution of the radioactive marine contamination during the first month of the accident. Results indicate for surface seawater concentrations ranging from 24.9 to 161.0 Bq/L for I-131 and 11.2 to 186.0 Bq/L for Cs-137, and for deep waters of 1.59-15.0 Bq/L (I-131) and 0.0-11.4 Bq/L (Cs-137). The I-131 concentrations in superficial waters were at or above Japanese regulatory limits in the first days, then lowered during one week to increase again above limits when TEPCO released contaminated water into the ocean, to finally reach not detectable values the last week of April. With the exception of point 4, on April 15, the Cs-137 levels were always well below regulatory limits. (author)

  17. Notes on the incorporation of third world women into wage-labor through immigration and off-shore production.

    Science.gov (United States)

    Sassen-koob, S

    1984-01-01

    The different forms and geographic locations in which the expanded incorporation of Third World women into wage labor occur may be closely interrelated. 2 such instances examined in this article are: 1) the recruitment of young women, without previous labor force experience, into the new manufacturing and service jobs generated by export-led manufacturing in several Caribbean and Asian countries; and 2) the employment of immigrant women in large cities of highly industrialized countries which have undergone basic economic restructuring. While many of these women may have become domestic or international migrants as a function of their husbands' or family's migration, the more fundamental processes of this restructuring are the ones promoting the formation of a supply of women migrants and a demand for this type of labor. Examples are the shift of plants and offices to Third World countries, and the demand for immigrant women labor in large cities within the US. The latter is a manifestation of the general shift to a service economy, the downgrading of manufacturing, partly to keep it competitive with overseas plants, and the direct and indirect demand for low-wage labor generated by the expansion of management and control functions centered in these large cities, and necessary for the regulation of the global economy. The feminization of job supply and the need to secure a politically adequate labor supply, which combine to create a demand for the type of labor represented by migrant women, suggest that gender has to be considered in conjunction with the structural arrangements and that gender by itself cannot adequately describe the nature of migrant labor.

  18. Off-shore enhanced oil recovery in the north sea: matching CO_2 demand and supply given uncertain market conditions

    Science.gov (United States)

    Compernolle, Tine; Welkenhuysen, Kris; Huisman, Kuno; Piessens, Kris; Kort, Peter

    2015-04-01

    Introduction CO2 enhanced oil recovery (CO2-EOR) entails the injection of CO2 in mature oil fields in order to mobilize the oil. In particular, the injected CO2 reduces the oil's viscosity and acts as a propellant, resulting in an increased oil extraction rate (Leach et al., 2011). Given uncertainty in both oil price and CO2 price under the EU ETS system, aim of this study is to analyze under which economic conditions a CO2 exchange can be established between a CO2 supplier (an electricity producer for whom CO2 is a by-product) and a CO2 user (an offshore oil company that exploits oil fields in the North Sea and needs CO2 for enhanced oil recovery). Methodology A techno-economic simulation tool, PSS IV, was developed to provide investment decision support on integrated CO2-EOR projects (Welkenhuysen et al., 2014). Until now, a fixed onshore supply of CO2 was presumed. An economic optimization model is now developed for both the CO2 producer and the CO2 user. Because net present value and discounted cash flow methods are inadequate to deal with issues like uncertainty and the irreversibility of an investment decision, the real options theory is applied (Dixit and Pindyck, 1994). The way in which cooperation between the companies can take place, will be studied using game theoretical concepts (Lukas and Welling, 2014). Economic and technical data on CO2 capture are available from the PSS database (Piessens et al., 2012). Data on EOR performance, CO2 requirements and various costs are taken from literature (BERR, 2007; Klokk et al., 2010; Pershad et al., 2012). Results/Findings It will be shown what the impact of price uncertainty is on the investment decision of the electricity producer to capture and sell CO2, and on the decision of the oil producer to make the necessary investments to inject CO2 for enhanced oil recovery. Based on these results, it will be determined under which economic conditions a CO2 exchange and transport can take place. Furthermore, also the role of the ETS system will be discussed. In an initial stage, only the CO2-price and oil price market uncertainties are considered. In a further stage, uncertainties from the supply side (technology) and EOR (geological) will be added. References BERR. 2007. Development of a CO2 transport and storage network in the North Sea: report to the North Sea Basin Task Force. Dixit A, Pindyck R (1994). Investment under Uncertainty. In, Princeton University Press. Klokk Ø, Schreiner PF, Pagès-Bernaus A, Tomasgard A (2010). Optimizing a CO2 value chain for the Norwegian Continental Shelf. Energy Policy 38(11): 6604-6614 Leach A, Mason CF, Veld Kvt (2011). Co-optimization of enhanced oil recovery and carbon sequestration. Resource Energy Econ 33(4): 893-912 Lukas E, Welling A (2014). Timing and eco(nomic) efficiency of climate-friendly investments in supply chains. Eur J Oper Res 233(2): 448-457 Pershad, H., Durusut, E., Crerar, A., Black, D., Mackay, E. & Oldern, P., 2012. Economic Impacts of CO2-enhanced oil recovery for Scotland, Final report for Scottish Enterprise. Element energy, London. Piessens, K., Welkenhuysen K., Laenen, B., Ferket, H., Nijs, W., Duerinck, J., Cochez, E., Mathieu, Ph., Valentiny, D., Baele, J.-M., Dupont, N. & Hendriks, Ch., 2012. Policy Support System for Carbon Capture and Storage and Collaboration between Belgium-the Netherlands "PSS-CCS", Final report. Belgian Science Policy Office, Research Programme Science for a Sustainable Development contracts SD/CP/04a,b & SD/CP/803, 335p. Welkenhuysen, K., Compernolle, T., Piessens, K., Ramírez, A., Rupert, J. & Swennen, R., 2014. Geological uncertainty and investment risk in CO2-enhanced oil recovery. 12th International Conference on Greenhouse Gas Control Technologies (GHGT-12), Austin, Texas, 05-09/10/2014.

  19. Effect of echolocation behavior-related constant frequency-frequency modulation sound on the frequency tuning of inferior collicular neurons in Hipposideros armiger.

    Science.gov (United States)

    Tang, Jia; Fu, Zi-Ying; Wei, Chen-Xue; Chen, Qi-Cai

    2015-08-01

    In constant frequency-frequency modulation (CF-FM) bats, the CF-FM echolocation signals include both CF and FM components, yet the role of such complex acoustic signals in frequency resolution by bats remains unknown. Using CF and CF-FM echolocation signals as acoustic stimuli, the responses of inferior collicular (IC) neurons of Hipposideros armiger were obtained by extracellular recordings. We tested the effect of preceding CF or CF-FM sounds on the shape of the frequency tuning curves (FTCs) of IC neurons. Results showed that both CF-FM and CF sounds reduced the number of FTCs with tailed lower-frequency-side of IC neurons. However, more IC neurons experienced such conversion after adding CF-FM sound compared with CF sound. We also found that the Q 20 value of the FTC of IC neurons experienced the largest increase with the addition of CF-FM sound. Moreover, only CF-FM sound could cause an increase in the slope of the neurons' FTCs, and such increase occurred mainly in the lower-frequency edge. These results suggested that CF-FM sound could increase the accuracy of frequency analysis of echo and cut-off low-frequency elements from the habitat of bats more than CF sound.

  20. Geographical variation in echolocation call and body size of the Okinawan least horseshoe bat, Rhinolophus pumilus (Mammalia: Rhinolophidae), on Okinawa-jima Island, Ryukyu Archipelago, Japan.

    Science.gov (United States)

    Yoshino, Hajime; Matsumura, Sumiko; Kinjo, Kazumitsu; Tamura, Hisao; Ota, Hidetoshi; Izawa, Masako

    2006-08-01

    The Okinawan least horseshoe bat, Rhinolophus pumilus, is a cave-dwelling species endemic to the central and southern Ryukyus, Japan. We analyzed variation in the constant frequency (CF) of the echolocation call and in forearm length (FAL) of this species on Okinawa-jima Island on the basis of data for 479 individuals from 11 caves scattered over the island. CF values in samples from six caves, all located in the southwestern half of Okinawa-jima, were significantly higher than those in samples from five caves in the northeastern half of the island. Also, FAL was significantly greater in the latter group than in the former group, although the ranges of variation in this character substantially overlapped between the two groups. These results suggest substantial differentiation between R. pumilus populations on Okinawa-jima. The implications of our findings for the conservation of this endangered bat species are briefly discussed.

  1. EXPERIMENTAL MEASUREMENTS OF TAILING UNDERWATER SEDIMENTS AND LIQUID INDUSTRIAL WASTES IN STORAGE TANK ON THE BASIS OF ECHOLOCATION AND GPS-SYSTEMS AT JSC “BELARUSKALI”

    Directory of Open Access Journals (Sweden)

    V. I. Mikhailov

    2016-01-01

    Full Text Available The paper presents a new approach to calculate volume of tailing underwater sediments and liquid industrial wastes on the basis of innovative technologies. Two theodolites which are set at various points and a boat with a load for measuring water depth have been traditionally used for topographic survey of slime storage bottom. Horizontal directions have been simultaneously measured on the boat marker while using theodolites. Water depth has been determined while using  a 2-kg circular load which was descended into brine solution with the help of rope. In addition to rather large time and labour costs such technology has required synchronization in actions on three participants involved in the work: operators of two theodolites and boat team in every depth measuring point. Methodology has been proposed for more efficient solution of the problem. It presupposes the use of echolocation together with space localization systems (GPS-systems which can be set on a boat with the purpose to measure depth of a storage tank bed. An echolocation transducer has been installed under the boat bottom at the depth of 10 cm from the brine solution level in the slime storage.  An aerial of GPS-receiver has been fixed over the echo-sounder transducer. Horizontal positioning of bottom depth measuring points have been carried out in the local coordinate system. Formation of digital model for slime storage bottom has been executed after data input of the coordinate positioning that corresponded to corrected depths in the software package LISCAD Plus SEE. The formation has been made on the basis of a strict triangulation method.  Creation of the digital model makes it rather easy to calculate a volume between a storage bottom and a selected level (height of filling material. In this context it is possible to determine a volume and an area not only above but also lower of the datum surface. For this purpose it is recommended to use digital models which are developed

  2. Active Listening in a Bat Cocktail Party: Adaptive Echolocation and Flight Behaviors of Big Brown Bats, Eptesicus fuscus, Foraging in a Cluttered Acoustic Environment.

    Science.gov (United States)

    Warnecke, Michaela; Chiu, Chen; Engelberg, Jonathan; Moss, Cynthia F

    2015-09-01

    In their natural environment, big brown bats forage for small insects in open spaces, as well as in vegetation and in the presence of acoustic clutter. While searching and hunting for prey, bats experience sonar interference, not only from densely cluttered environments, but also from calls of conspecifics foraging in close proximity. Previous work has shown that when two bats compete for a single prey item in a relatively open environment, one of the bats may go silent for extended periods of time, which can serve to minimize sonar interference between conspecifics. Additionally, pairs of big brown bats have been shown to adjust frequency characteristics of their vocalizations to avoid acoustic interference in echo processing. In this study, we extended previous work by examining how the presence of conspecifics and environmental clutter influence the bat's echolocation behavior. By recording multichannel audio and video data of bats engaged in insect capture in open and cluttered spaces, we quantified the bats' vocal and flight behaviors. Big brown bats flew individually and in pairs in an open and cluttered room, and the results of this study shed light on the different strategies that this species employs to negotiate a complex and dynamic environment. © 2015 S. Karger AG, Basel.

  3. The Relationship Between Protein Fractions of Wheat Gluten and the Quality of Ring-Shaped Rolls Evaluated by the Echolocation Method

    Directory of Open Access Journals (Sweden)

    Grazina Juodeikiene

    2005-01-01

    Full Text Available This paper presents the results of the relationship between separate protein fractions and the quality of baked ring-shaped rolls. The qualitative and quantitative protein composition of flour derived from some wheat varieties grown in Lithuania has been determined. The protein properties are evaluated by SDS-PAGE. A new method of the analysis of swelling, based on the principle of echolocation, has been used to determine the quality of this specific kind of baked goods. For the application of this method the wheat flour, which is most suitable for the production of ring-shaped rolls, made from the wheat variety Portal (Pasvalys PVRS, has been selected. This flour has the following quality parameters: proteins 10.5 %, gluten 22.0 %, gluten index 47 r.u. Correlation between the flour quality parameters and the quality of the final bread product shows that γ-gliadins (r=–0.63, LMM glutenins (r=0.55, HMM glutenins (r=0.63 and the content of gluten (r=0.87 have the greatest influence on the quality of the ring-shaped rolls.

  4. Geographical Variation in Echolocation Call and Body Size of the Okinawan Least Horseshoe Bat, Rhinolophus pumilus(Mammalia: Rhinolophidae), on Okinawa-jima Island, Ryukyu Archipelago, Japan(Animal Diversity and Evolution)

    OpenAIRE

    Hajime, Yoshino; Sumiko, Matsumura; Kazumitsu, Kinjo; Hisao, Tamura; Hidetoshi, Ota; Masako, Izawa; Laboratory of Evolution and Ecology, Faculty of Science, University of the Ryukyus; Faculty of Science, Yamaguchi University; Department of Law, Okinawa International University; Asian Bat Research Institute; Tropical Biosphere Research Center, University of the Ryukyus; Laboratory of Evolution and Ecology, Faculty of Science, University of the Ryukyus

    2006-01-01

    The Okinawan least horseshoe bat, Rhinolophus pumilus, is a cave-dwelling species endemic to the central and southern Ryukyus, Japan. We analyzed variation in the constant frequency (CF) of the echolocation call and in forearm length (FAL) of this species on Okinawa-jima Island on the basis of data for 479 individuals from 11 caves scattered over the island. CF values in samples from six caves, all located in the southwestern half of Okinawa-jima, were significantly higher than those in sampl...

  5. A GESTÃO DO CONHECIMENTO E OS PROCESSOS DE INFORMAÇÕES NAS ORGANIZAÇÕES: ESTUDO DE CASO EM UMA EMPRESA OFF SHORE

    Directory of Open Access Journals (Sweden)

    Carlos Navarro Fontanillas

    2012-08-01

    Full Text Available The increasing competitiveness and increasingly rapid changes taking place from the latetwentieth century have led companies to adopt new models of management and organizationto suit the modern business world and capitalist. Thus, knowledge and intellectual capital arebecoming increasingly important and essential to companies that achieve competitiveadvantage and to sustain in the market, must be prepared to change and to manage their assets,especially intangible. As a result of these dynamics, one can observe that one of thedifficulties faced by companies today is the frequent turnover of employees. In Brazil,according to the IBGE, in 2006, this appointment came to the range of 13%, while in 1999represented only 6% (IBGE 2009. This factor coupled to little standardization of processesand together with the lack of information sharing, resulting in loss of knowledge andconsequent costs for the company. Nevertheless, knowledge management becomes a majorchallenge for organizations today, for creating, managing and sharing knowledge within acompany are tasks that involve, among other things, the practices and beliefs aboutmanagement processes, people and systemic vision of the organization. And although thesefactors need to be well aligned with organizational strategies often do not present themselvesthat way.

  6. Estimating slip deficit of the North Anatolian Fault beneath the Sea of Marmara, Turkey, using on- and off-shore geodetic data

    Science.gov (United States)

    Yamamoto, R.; Kido, M.; Ohta, Y.; Takahashi, N.; Yamamoto, Y.; Kalafat, D.; Pinar, A.; Ozener, H.; Ozeren, M. S.; Yoshiyuki, K.

    2016-12-01

    The North Anatolian Fault (NAF) in the northern Turkey regionally has right-lateral strike-slip motion. In the last decade, seismic activities have been migrating from east to west along the fault. In 1999, Izmit and Duzce Earthquakes were respectively occurred at 100 km and 200 km east of Istanbul, while it remains un-ruptured in the vicinity of Istanbul beneath the Sea of Marmara. In this region, onshore geodetic tools cannot be used and we instead used "seafloor acoustic extensometers" to detect slip deficit rate across the western part of the NAF (around 27.7 °E). A pair of extensometers can periodically measure precise range (about 3-4 mm precision per 1 km baseline) by observing round-trip time of acoustic signal between the two. We installed four instruments in September 2014 and an additional one in March 2015 across the NAF. We have recovered data for about 600-days through acoustic modem. By correcting travel-times for sound velocity using concurrently measured temperature, pressure and tilt change of instruments, we obtained 8-10 ±1 mm/yr of right-lateral movement at the site. Combing the result with on-shore GNSS data across the Sea of Marmara, we constructed a possible fault model. According to the model in Kaneko et al. (2013), we simply assume a bimodal slip condition on the fault plane that infinitely continues to the E-W direction; full-creep (25 mm/yr as is given at infinite distant from the fault plane) deeper than 15 km and applied an overriding partially locked layer (17 mm/yr slip deficit as is obtained by extensometers). We calculated 2-D displacement field in a homogeneous elastic half-space medium. With this model, N-S variation of on-shore GNSS data across the Sea of Marmara can be reasonably explained. However, due to the lack of GNSS site near the fault plane, constraint on the depth of the partially locked layer is not sufficient. We have newly installed GNSS sites, one of which is closer to the fault plane ( 10 km) than before and will be expected to provide much information on the fault condition. Acknowledgement: This observation is carried out in the MarDiM (Marmara Disaster Mitigation) project, SATREPS promoted by JICA/JST and Ministry of Development of Turkey.

  7. The atmospheric boundary layer over land and sea: Focus on the off-shore Southern Baltic and Southern North Sea region

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling

    Lecture notes for a short course on the ideal atmospheric boundary layer and its characteristics for different types of real boundary layers, aiming at a discussion of the coastal conditions at the Southern Baltic and North Sea region. The notes are aimed at young scientists (e.g. PhD students......) that study the physics of the atmospheric boundary layer with the purpose of applying this knowledge for remote sensing techniques within offshore wind energy....

  8. Environmental data for the planning of off-shore wind parks from the EnerGEO Platform of Integrated Assessment (PIA)

    Energy Technology Data Exchange (ETDEWEB)

    Zelle, Hein; Mika, Agnes; Calkoen, Charles; Santbergen, Peter [BMT ARGOSS, Marknesse (Netherlands); Blanc, Isabelle; Guermont, Catherine; Menard, Lionel; Gschwind, Benoit [MINES ParisTech, Sophia Antipolis (France)

    2013-07-01

    The EU-sponsored EnerGEO project aims at providing decision makers with a modelling platform to assess the environmental impacts of different sources of renewable energy. One of the pillars of the project is the Wind Energy Pilot, addressing the effects of offshore wind parks on air pollution and energy use. The methods used in the pilot and the underlying environmental databases are integrated into a WebGIS client tool and made available to the public. This paper is dedicated to describing the environmental databases and supporting data incorporated in the client tool. A 27-km resolution, 11-year wind database is created using the WRF model. The wind database is used to assess the wind climate in the north-west Atlantic region and to derive the potential power output from offshore wind parks. Auxiliary data concerning water depth, distance to shore and distance to the nearest suitable port are created to aid the planning and maintenance phases. Seasonal workability conditions are assessed using a 20-year wave database. The distance at which future wind parks should be placed to exhibit different wind climates is investigated. (orig.)

  9. Environmental data for the planning of off-shore wind parks from the EnerGEO Platform of Integrated Assessment (PIA)

    International Nuclear Information System (INIS)

    Zelle, Hein; Mika, Agnes; Calkoen, Charles; Santbergen, Peter; Blanc, Isabelle; Guermont, Catherine; Menard, Lionel; Gschwind, Benoit

    2013-01-01

    The EU-sponsored EnerGEO project aims at providing decision makers with a modelling platform to assess the environmental impacts of different sources of renewable energy. One of the pillars of the project is the Wind Energy Pilot, addressing the effects of offshore wind parks on air pollution and energy use. The methods used in the pilot and the underlying environmental databases are integrated into a WebGIS client tool and made available to the public. This paper is dedicated to describing the environmental databases and supporting data incorporated in the client tool. A 27-km resolution, 11-year wind database is created using the WRF model. The wind database is used to assess the wind climate in the north-west Atlantic region and to derive the potential power output from offshore wind parks. Auxiliary data concerning water depth, distance to shore and distance to the nearest suitable port are created to aid the planning and maintenance phases. Seasonal workability conditions are assessed using a 20-year wave database. The distance at which future wind parks should be placed to exhibit different wind climates is investigated. (orig.)

  10. Development and Testing of Embedded Gridding Within the Regional Ocean Modeling System: Interaction Between Near-Shore Off-Shore Currents and Material Properties

    National Research Council Canada - National Science Library

    McWilliams, James

    2003-01-01

    ...) continuing the development of the Regional Ocean Modeling System (ROMS) with respect to its hydrodynamic algorithms, physical transport parameterizations, and range of biogeochemical processes; (2...

  11. Examination of fault ride-through methods for off-shore wind farms connected to the grid through VSC-based HVDC transmission

    Energy Technology Data Exchange (ETDEWEB)

    Karaagac, U.; Mahseredjian, J.; Saad, H. [Ecole Polytechnique de Montreal, QC (Canada); Jensen, S.; Cai, L. [REpower Systems AG, Hamburg (Germany)

    2012-07-01

    The fault ride-through (FRT) performance of offshore wind farms (OWFs) is a challenging task when the OWF is connected to the onshore ac grid through a voltage source converter (VSC) based HVDC transmission system. The injected power from the OWF cannot be reduced by the offshore VSC during onshore ac faults and this causes a fast increase in the dc network voltage. Without any special FRT method, the dc network voltage may increase up to intolerable levels and cause operation of dc overvoltage protection. This paper compares various FRT methods based on fast reduction of power generation in OWFs. In addition, this paper proposes an improved FRT method based on controlled voltage drop for output power reduction in OWFs. The proposed improvement reduces mechanical stress on the wind turbine (WT) drive train, and electrical stress on the insulated gate bipolar transistors (IGBTs) of the HVDC and doubly-fed induction generator (DFIG) converters. Practical onshore ac fault scenarios are simulated for an OWF composed of DFIG type WTs and connected to a practical ac grid through a point-to-point modular multilevel converter (MMC) based HVDC system. (orig.)

  12. Local scale atmospheric diffusion at a coastal site in the presence of breeze effect (Phase I and II: data collection at a coastal site and off shore)

    International Nuclear Information System (INIS)

    Cagnetti, P.; Ferrara, V.; Pellegrini, A.

    1985-01-01

    The aim of this contract is the characterization, from the thermal and anemological point of view of the lower layers of the atmosphere at a coastal site, affected by breeze circulation. Data are utilized to set up diffusion models for accidental releases of airborne materials, both of short and prolonged duration. Five inland meteorological campaigns, starting from Jan. 82 (Jan., Apr., Jul., Oct. 1982, Jan. 1983), have been carried out; an appropriate extension of the contract allowed the execution of two more campaigns in the open sea (Apr., Jul. 1983), utilizing the oceanographic ship ''Bannock'' kindly supplied by CNR. The analysis of the data showed the development of a well defined IBL during on-shore flow only in Spring and Summer, while an inversion layer was detectable aloft independently of the season (provided that an anticyclonic situation was present). According to those relevant features a simple diffusion model has been developed for short duration releases at local scale. Finally, the analysis and elaboration of the data, collected on site by a meteorological automatic station, allowed the extension of the model to prolonged releases

  13. Monitoring of Hydrocarbons in Sediment and Biota Related to Oil and Gas Development in Near- and Off-Shore Areas of the Arctic Beaufort Sea, Alaska

    Science.gov (United States)

    Durell, G.; Hardin, J.; Libby, S.

    2016-02-01

    There is increasing interest in extracting oil and gas from offshore environments of Alaska. The Arctic Nearshore Impact Monitoring in Development Area (ANIMIDA) project, started in 1999, has been producing information to evaluate potential effects of oil and gas activities in the Alaskan Beaufort Sea. ANIMIDA was preceded by the Beaufort Sea Monitoring Program. Monitoring has mostly been in pre-drilling locations, but also during development and production periods. Surveys were conducted to assess bottom sediment, sediment cores, suspended sediment, and biota for polycyclic aromatic hydrocarbons (PAH), saturated hydrocarbons, biological and petroleum markers, and geophysical parameters. The concentrations measured in sediments and biota were at or near background throughout most of the Beaufort Sea. There were no significant differences between exploration, production, and background locations, and the concentrations were consistently below those of ecological concern. For instance, TPAH in sediment ranged from below 100 to about 1,000 µg/kg and were controlled primarily by sediment characteristics (e.g., grain size and organic carbon). Hydrocarbons in sediments were from petrogenic, pyrogenic, and biogenic sources. Small areas with indications of input of anthropogenic chemicals were identified by sensitive diagnostic analysis techniques and are possibly associated with historic exploratory drilling and vessels. Sediment cores indicate a uniform historical deposition of hydrocarbons, although some evidence of past drilling activities were observed. Fish, amphipods, and clams contained background levels of hydrocarbons and showed no evidence of effects from accumulation of contaminants; TPAH concentrations were below 100 µg/kg in most biota. Noteworthy interannual fluctuations were observed for PAH concentrations in sediment and biota, likely due to winnowing of sediment fines by large storms and annual variations in river discharges. Significant natural sources were identified; rivers deliver about 80% of the annual suspended solids to Beaufort Sea within a 2-3 week period each spring with significant input of hydrocarbons from terrestrial sources. The ANIMIDA project has provided monitoring information that can confidently be used for future environmental management.

  14. Echolocation calls and morphology in the Mehelyi’s (Rhinolophus mehelyi and mediterranean (R. euryale horseshoe bats: implications for resource partitioning

    Directory of Open Access Journals (Sweden)

    Egoitz Salsamendi

    2006-03-01

    Full Text Available Abstract Rhinolophus euryale and R. mehelyi are morphologically very similar species and their distributions overlap extensively in the Mediterranean basin. We modelled their foraging behaviour using echolocation calls and wing morphology and, assuming niche segregation occurs between the two species, we explored how it is shaped by these factors. Resting frequency of echolocation calls was recorded and weight, forearm length, wing loading, aspect ratio and wing tip shape index were measured. R. mehelyi showed a significantly higher resting frequency than R. euryale, but differences are deemed insufficient for dietary niche segregation. Weight and forearm length were significantly larger in R. mehelyi. The higher values of aspect ratio and wing loading and a lower value of wing tip shape index in R. melehyi restrict its flight manoeuvrability and agility. Therefore, the flight ability of R. mehelyi may decrease as habitat complexity increases. Thus, the principal mechanism for resource partitioning seems to be based on differing habitat use arising from differences in wing morphology. Riassunto Ecolocalizzazione e morfologia nei rinolofi di Mehely (Rhinolophus mehelyi e euriale (R. euryale: implicazioni nella segregazione delle risorse trofiche. Rhinolophus euryale e R. mehelyi sono specie morfologicamente molto simili, la cui distribuzione risulta largamente coincidente in area mediterranea. Il comportamento di foraggiamento delle due specie è stato analizzato in funzione delle caratteristiche dei segnali di ecolocalizzazione e della morfologia alare, ed è stata valutata l’incidenza di questi fattori nell’ipotesi di una segregazione delle nicchie. È stata rilevata la frequenza a riposo dei segnali ultrasonori, così come il peso, la lunghezza dell’avambraccio, il carico alare, e due

  15. Off-shore Wind Atlas of the Central Aegean Sea: A simple comparison of NCEP/NCAR RE-analysis data, QuickSCAT and ENVISAT Synthetic Aperture Radar (SAR) by use of Wind Atlas Method

    DEFF Research Database (Denmark)

    Bingöl, Ferhat; Hasager, Charlotte Bay; Karagali, Ioanna

    2012-01-01

    model results). Unfortunately all of these methods are still under development and do not provide data acceptable for bankable wind assessment reports. On the other hand, they give good indications of the geographical distribution of the wind resources and that is very useful for decision making...... to high costs, but with the new developments in floating turbine design, it seems that offshore wind parks in deep waters will also be a possibility in the future. Whether on-shore or offshore, the first step of a site assessment is to estimate the wind resources. Usually well-known conventional methods...... are used to produce estimates of wind resources by means of at least one year data from a single or multiple points on the terrain. This criterion is dicult to satisfy in offshore locations where measurements are costly and sparse. Therefore other methods are required (e.g satellite imagery or reanalysis...

  16. Analysis on the furthering of competition in relation to the establishment of large off-shore wind farms in Denmark. Main report; Analyse vedroerende fremme af konkurrence ved etablering af store havmoelleparker i Danmark. Hovedrapport

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Carsten; Enevoldsen, M [Deloitte, Copenhagen (Denmark)

    2011-04-15

    The report, based on the 2010 tender for Anholt Offshore Wind Farm, is an analysis of how competition in the offshore wind power area can be increased, and a lower consumer price achieved. The study concludes that there is broad support for the Danish tender model among relevant parties, just as the process of working with Danish authorities and connecting to the power grid were viewed positively by potential investors in Danish offshore wind farms. But the report also found that inflexible guidelines in the Anholt Offshore Wind Farm tender contributed to a higher settlement price. One example singled out by the report was the threat of drastic fines and short deadlines. Moreover, the tender also occurred at a time when the production of wind turbines and foundations could not keep pace with increasing demand, particularly in Germany and the United Kingdom. Deloitte forecasts that the price for building and operating offshore wind farms, despite the increasing demand for offshore wind turbines, can be cut by between 25% and 30% by 2020, given the right framework guidelines and tender conditions. Applied to the planned Kriegers Flak Offshore Wind Farm, this calculation would result in a settlement price of between DKK 0.781 and DKK 0.979/kWh. The settlement price for Anholt Offshore Wind farm is currently DKK 1.051/kWh. The report recommends that the tender be altered to permit a greater dialogue with potential bidders, and to allow for information about the tenders to be spread internationally. Deloitte's report is based on interviews with individuals from a number of energy companies, investors, and public agencies, and takes into account other countries' experiences building offshore wind farms, as well as an evaluation of the competitive conditions within the offshore wind sector. (ENS)

  17. Cost-Efficient and sustainable deployment of renewable energy sources towards the 20% target by 2020, and beyond. D3.3. Off Shore wind energy - Case study of cooperation mechanisms design

    Energy Technology Data Exchange (ETDEWEB)

    Klinge Jacobsen, H.; Pade Hansen, L.-L. [Technical Univ. of Denmark. DTU Management Engineering, Roskilde (Denmark); Jansen, J. [ECN, Petten (Netherlands)

    2012-10-15

    Denmark is projected to have by 2020 a large excess potential for offshore wind capacity in the North Sea at shallow and near to the coast locations. The Netherlands on the other hand has low and expensive RES potentials for its 2020 RES target obligations. Therefore offshore wind potentials in Denmark constitute a possible cost reduction for the Netherlands in meeting its 2020 RES target. This case study examines a large amount of 2 GW offshore wind capacity in the Danish North Sea area. Cooperation unfolds in a joint project type with state to state negotiation and settlement. Different timing and implementation options are described with the possibility to implement a series of 200 MW joint projects with negotiation for each separate phase. The case study is focusing on the area around Horns Rev, where wind conditions are good, the distance to shore is 20-30 km and water depth is around 25 m. With these conditions the cost level will be around 12 c Euro/kWh and that is at least a 3 c Euro/kWh cost advantage to the expansion with offshore wind in the Netherlands. Joint project cooperation is a simple form of cooperation that does not involve a restructuring of national support schemes and legislator changes that can take a long time to implement and affect a lot of entities in the host country. Projects are negotiated between the host and the user country, with the major task to settle a transfer price for the credits transferred in 2020. The design of cooperation assigns the entire project risk to the host country as the host is the party that enters into the contract with the investors in renewable energy capacity. This case study identifies the main barriers for the joint project cooperation and concludes that the main barriers to cooperation between Denmark and the Netherlands is the missing detailed knowledge on the penalty for non-compliance with the 2020 targets, and the lack of post 2020 targets in the EU policy. The missing knowledge on the penalty may on the overall terms prevent cooperation. Only the issue of the lack of post 2020 targets is expected to constitute a challenge to the actual design of the cooperation and will be handled in the negotiations of the RES transfer price. In the actual negotiations over the transfer price in 2020 there are two very different options. One option is to transfer the generated RES credits from the additional capacity for the whole lifetime of this capacity. This will involve a large amount of support from the user country which will be a very high price if the credits are only measured in comparison to the 2020 obligations that the Netherlands have to meet. Another option is only to acquire the RES credits generated in the year 2020, if the host country have a national (domestic) value for the post 2020 RES generation or expect that EU targets will be increased post 2020 and credit prices will have another level after 2020. This is a special situation that might be especially relevant for the cooperation between Denmark and the Netherlands as Denmark has national targets for RES beyond 2020 that are considerably higher than the EU target for 2020. In the case study sensitivity regarding this critical assumption about future credit prices (national value of RES) reveals that the single year price for credits heavily depends on this expectation. Apart from national targets it depends on the policy actions expected from the EU on setting future targets. Reducing the uncertainty can be established by having EU policy determining that the RES targets after 2020 will be at least slightly increased for all countries, and that the target level for 2020 is also binding for later years. (LN)

  18. Analysis on the furthering of competition in relation to the establishment of large off-shore wind farms in Denmark. Main report; Analyse vedroerende fremme af konkurrence ved etablering af store havmoelleparker i Danmark. Hovedrapport

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Carsten; Enevoldsen, M. (Deloitte, Copenhagen (Denmark))

    2011-04-15

    The report, based on the 2010 tender for Anholt Offshore Wind Farm, is an analysis of how competition in the offshore wind power area can be increased, and a lower consumer price achieved. The study concludes that there is broad support for the Danish tender model among relevant parties, just as the process of working with Danish authorities and connecting to the power grid were viewed positively by potential investors in Danish offshore wind farms. But the report also found that inflexible guidelines in the Anholt Offshore Wind Farm tender contributed to a higher settlement price. One example singled out by the report was the threat of drastic fines and short deadlines. Moreover, the tender also occurred at a time when the production of wind turbines and foundations could not keep pace with increasing demand, particularly in Germany and the United Kingdom. Deloitte forecasts that the price for building and operating offshore wind farms, despite the increasing demand for offshore wind turbines, can be cut by between 25% and 30% by 2020, given the right framework guidelines and tender conditions. Applied to the planned Kriegers Flak Offshore Wind Farm, this calculation would result in a settlement price of between DKK 0.781 and DKK 0.979/kWh. The settlement price for Anholt Offshore Wind farm is currently DKK 1.051/kWh. The report recommends that the tender be altered to permit a greater dialogue with potential bidders, and to allow for information about the tenders to be spread internationally. Deloitte's report is based on interviews with individuals from a number of energy companies, investors, and public agencies, and takes into account other countries' experiences building offshore wind farms, as well as an evaluation of the competitive conditions within the offshore wind sector. (ENS)

  19. Echolocation click source parameters of Australian snubfin dolphins (Orcaella heinsohni)

    DEFF Research Database (Denmark)

    de Freitas, Mafalda; Smith, Joshua N; Jensen, Frants H

    2018-01-01

    The Australian snubfin dolphin (Orcaella heinsohni) is endemic to Australian waters, yet little is known about its abundance and habitat use. To investigate the feasibility of Passive Acoustic Monitoring for snubfin dolphins, biosonar clicks were recorded in Cygnet Bay, Australia, using a four-el...

  20. Echolocation caBs of twenty southern African bat species

    African Journals Online (AJOL)

    riori. matching their ~onograms and call parameters with pre- viously obtained ... Mkuzi Game Reserve, Dundee and 10zini Dam in KwaZulu-. Natal province of .... FM) 'N' refers to the number of IndiVidual calls analysed. AbbreViations of ...

  1. Anthropogenic noise alters bat activity levels and echolocation calls

    OpenAIRE

    Bunkley, Jessie P.; McClure, Christopher J.W.; Kleist, Nathan J.; Francis, Clinton D.; Barber, Jesse R.

    2015-01-01

    Negative impacts from anthropogenic noise are well documented for many wildlife taxa. Investigations of the effects of noise on bats however, have not been conducted outside of the laboratory. Bats that hunt arthropods rely on auditory information to forage. Part of this acoustic information can fall within the spectrum of anthropogenic noise, which can potentially interfere with signal reception and processing. Compressor stations associated with natural gas extraction produce broadband nois...

  2. [Letter: Work of the impulse section of the horseshoe bat echolocator].

    Science.gov (United States)

    Livshits, M S

    1975-01-01

    Peculiarities of location impulse of Rhinolophidae bring about a distinctive combination of dopler and impulse parts working almost independently, in its locator. In particular the range of the effect of impulse locator connected with the presence of LFM splash in the end of location cry is determined by the value of the period of its repetition. The existence of a long monofrequent part of locaion impulse providing the work of acholocator dopler part due to its narrow bands presents only a comparatively small obstacle to the impulse locator.

  3. The effect of call libraries and acoustic filters on the identification of bat echolocation

    Science.gov (United States)

    Clement, Matthew; Murray, Kevin L; Solick, Donald I; Gruver, Jeffrey C

    2014-01-01

    Quantitative methods for species identification are commonly used in acoustic surveys for animals. While various identification models have been studied extensively, there has been little study of methods for selecting calls prior to modeling or methods for validating results after modeling. We obtained two call libraries with a combined 1556 pulse sequences from 11 North American bat species. We used four acoustic filters to automatically select and quantify bat calls from the combined library. For each filter, we trained a species identification model (a quadratic discriminant function analysis) and compared the classification ability of the models. In a separate analysis, we trained a classification model using just one call library. We then compared a conventional model assessment that used the training library against an alternative approach that used the second library. We found that filters differed in the share of known pulse sequences that were selected (68 to 96%), the share of non-bat noises that were excluded (37 to 100%), their measurement of various pulse parameters, and their overall correct classification rate (41% to 85%). Although the top two filters did not differ significantly in overall correct classification rate (85% and 83%), rates differed significantly for some bat species. In our assessment of call libraries, overall correct classification rates were significantly lower (15% to 23% lower) when tested on the second call library instead of the training library. Well-designed filters obviated the need for subjective and time-consuming manual selection of pulses. Accordingly, researchers should carefully design and test filters and include adequate descriptions in publications. Our results also indicate that it may not be possible to extend inferences about model accuracy beyond the training library. If so, the accuracy of acoustic-only surveys may be lower than commonly reported, which could affect ecological understanding or management decisions based on acoustic surveys.

  4. Strong matrilineal structure in common pipistrelle bats (Pipistrellus pipistrellus) is associated with variability in echolocation calls

    Czech Academy of Sciences Publication Activity Database

    Fornůsková, Alena; Petit, E.J.; Bartonička, T.; Kaňuch, P.; Butet, A.; Řehák, Z.; Bryja, Josef

    2014-01-01

    Roč. 113, č. 4 (2014), s. 1115-1125 ISSN 0024-4066 R&D Projects: GA ČR GA206/06/0954 Institutional support: RVO:68081766 Keywords : dialects * maternal effects * sex-biased dispersal * philopatry * vocal learning Subject RIV: EG - Zoology Impact factor: 2.264, year: 2014

  5. Sperm whale long-range echolocation sounds revealed by ANTARES, a deep-sea neutrino telescope

    NARCIS (Netherlands)

    André, M.; Caballé, A.; van der Schaar, M.; Solsona, A.; Houégnigan, L.; Zaugg, S.; Sánchez, A.M.; Castell, J.V.; Solé, M.; Vila, F.; Djokic, D.; Adrián-Martínez, S.; Albert, A.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Avgitas, T.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bormuth, R.; Bouwhuis, M.C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Celli, S.; Chiarusi, T.; Circella, M.; Coleiro, A.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Deschamps, A.; De Bonis, G.; Distefano, C.; Di Palma, I.; Donzaud, C.; Dornic, D.; Drouhin, D.; Eberl, T.; El Bojaddaini, I.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fusco, L.A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Glotin, H.; Gracia-Ruiz, R.; Graf, K.; Hallmann, S.; van Haren, H.; Heijboer, A.J.; Hello, Y.; Hernandez-Rey, J.J.; Hößl, J.; Hofestädt, J.; Hugon, C.; Illuminati, G.; James, C.W.; de Jong, M.; Jongen, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kouchner, A.; Kreter, M.; Kreykenbohm, I.; Kulikovskiy, V.; Lachaud, C.; Lahmann, R.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J.A.; Mathieu, A.; Melis, K.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Nezri, E.; Pavalas, G.E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Roensch, K.; Saldaña, M.; Samtleben, D.F.E.; Sanguineti, M.; Sapienza, P.; Schnabel, J.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Stolarczyk, T.; Sánchez-Losa, A.; Taiuti, M.; Trovato, A.; Tselengidou, M.; Turpin, D.; Tönnis, C.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J.D.; Zuniga, J.

    2017-01-01

    Despite dedicated research has been carried out to adequately map the distribution of the spermwhale in the Mediterranean Sea, unlike other regions of the world, the species population status is stillpresently uncertain. The analysis of two years of continuous acoustic data provided by the

  6. From echolocation clicks to animal density – acoustic sampling of harbour porpoises with static dataloggers

    DEFF Research Database (Denmark)

    Kyhn, Line Anker; Tougaard, Jakob; Thomas, L.

    2012-01-01

    Monitoring abundance and population trends of small odontocetes is notoriously difficult and labour intensive. There is a need to develop alternative methods to the traditional visual line transect surveys, especially for low density areas. Here, the prospect of obtaining robust density estimates....... This provides a method suitable for monitoring in areas with densities too low for visual surveys to be practically feasible, e.g. the endangered harbour porpoise population in the Baltic....... for porpoises by passive acoustic monitoring (PAM) is demonstrated by combining rigorous application of methods adapted from distance sampling to PAM. Acoustic dataloggers (T-PODs) were deployed in an area where harbour porpoises concurrently were tracked visually. Probability of detection was estimated...

  7. Indirect interception actions by blind and visually impaired perceivers: echolocation for interceptive actions.

    Science.gov (United States)

    Vernat, Jean-Philippe; Gordon, Michael S

    2010-02-01

    This research examined the acoustic information used to support interceptive actions by the blind. Congenitally blind and severely visually impaired participants (all wearing an opaque, black eye-mask) were asked to listen to a target ball rolling down a track. In response, participants rolled their own ball along a perpendicular path to intercept the target. To better understand what information was used the echoic conditions and rolling dynamics of the target were varied across test sessions. In addition the rolling speed of the target and the distance of the participant from the target were varied across trials. Results demonstrated that participants tended to perform most accurately at moderate speeds and distances, overestimating the target's arrival at the fastest speed, and underestimating it at the slowest speed. However, changes to the target's dynamics, that is, the amount of deceleration it underwent on approach, did not strongly influence performance. Echoic conditions were found to affect performance, as participants were slightly more accurate in conditions with faster, higher-intensity echoes. Based on these results blind individuals in this research seemed to be using spatial and temporal cues to coordinate their interceptive actions.

  8. Effect of Broadband Nature of Marine Mammal Echolocation Clicks on Click-Based Population Density Estimates

    Science.gov (United States)

    2015-09-30

    University of St Andrews St Andrews , Scotland KY16 9LZ phone: +44 (1334) 461801 fax: +44 (1334) 461800 email: len.thomas@st-andrews.ac.uk...Peter Tyack Sea Mammal Research Unit (SMRU) and Scottish Oceans Institute (SOI) University of St Andrews St Andrews , Scotland phone: +44 (1334...University of St Andrews : Thomas (CREEM), Tyack (SMRU) Key individuals at TNO: Ainslie, von Benda-Beckmann Technical approach: This project is in

  9. Echolocation in two very small bats from Thailand Craseonycteris thonglongyai and Myotis siligorensis

    DEFF Research Database (Denmark)

    Surlykke, Annemarie; Miller, Lee A.; Møhl, Bertel

    1993-01-01

    and Vespertilionoidea, respectively. In spite of their phylogenetic distance they produce strikingly similar search signals of narrow BW around 70 kHz with high source levels (100-115 dB peSPL peak equivalent sound pressure level). We argue that the signal resemblance is due to the similarity in size and hunting...... explained by physiological limitations in sound production. However, C. thonglongyai produced very short signals at very high repetition rates without any frequency drop. The drop may be of adaptive value since it enables M. siligorensis to produce very short signals with high sweep rates. The drop moves...... the prey size. Hence, the two bats can only maximize the range of their sonar by decreasing the BW and emitting high intensities....

  10. Offshore Vendors’ Software Development Team Configurations

    DEFF Research Database (Denmark)

    Chakraborty, Suranjan; Sarker, Saonee; Rai, Sudhanshu

    2012-01-01

    This research uses configuration theory and data collected from a major IT vendor organization to examine primary configurations of distributed teams in a global off-shoring context. The study indicates that off-shoring vendor organizations typically deploy three different types of configurations...

  11. Bringing the Offshore Ashore : Transnational Production, Industrial Relations and the Reconfiguration of Sovereignty

    NARCIS (Netherlands)

    Lillie, Nathan

    This article argues that off-shore is losing its exceptionality by being absorbed into a broader process of variegation and deterritorialization of sovereignty, and that capital's search for a new "fix" is driving this process. Capital goes off-shore by exploiting non-territorial definitions of

  12. Learning from ‘apparent consensus’ in TAC disputes: Exploring knowledge overlaps in LEK and genetic categorization of Atlantic cod

    DEFF Research Database (Denmark)

    Hedeholm, R. B.; Jacobsen, R. B.; Eg Nielsen, Einar

    2016-01-01

    and the corresponding genetic categories. However, an examination of existing inshore and off-shore catch surveys confirmed the relevance of the morphological characteristics (liver condition and shape) of ecologically defined inshore and off-shore cod that provided the basis for fishers' categorizations. This opens...

  13. Satellite SAR wind resource mapping in China (SAR-China)

    DEFF Research Database (Denmark)

    Badger, Merete

    The project ‘Off-Shore Wind Energy Resource Assessment and Feasibility Study of Off-Shore Wind Farm Development in China’ is funded by the EU-China Energy and Environment Programme (EEP) and runs for one year (August 2008 - August 2009). The project is lead by the China Meteorological Administrat...

  14. Cost optimization of wind turbines for large-scale offshore wind farms

    International Nuclear Information System (INIS)

    Fuglsang, P.; Thomsen, K.

    1998-02-01

    This report contains a preliminary investigation of site specific design of off-shore wind turbines for a large off-shore wind farm project at Roedsand that is currently being proposed by ELKRAFT/SEAS. The results were found using a design tool for wind turbines that involve numerical optimization and aeroelastic calculations of response. The wind climate was modeled in detail and a cost function was used to estimate costs from manufacture and installation. Cost of energy is higher for off-shore installations. A comparison of an off-shore wind farm site with a typical stand alone on-shore site showed an increase of the annual production of 28% due to the difference in wind climate. Extreme loads and blade fatigue loads were nearly identical, however,fatigue loads on other main components increased significantly. Optimizations were carried out to find the optimum overall off-shore wind turbine design. A wind turbine for the off-shore wind farm should be different compared with a stand-alone on-shore wind turbine. The overall design changed were increased swept area and rated power combined with reduced rotor speed and tower height. Cost was reduced by 12% for the final 5D/14D off-shore wind turbine from 0.306 DKr/kWh to 0.270 DKr/kWh. These figures include capital costs from manufacture and installation but not on-going costs from maintenance. These results make off-shore wind farms more competitive and comparable to the reference on-shore stand-alone wind turbine. A corresponding reduction of cost of energy could not be found for the stand alone on-shore wind turbine. Furthermore the fatigue loads on wind turbines in on-shore wind farms will increase and cost of energy will increase in favor of off-shore wind farms. (au) EFP-95; EU-JOULE-3; 21 tabs., 7 ills., 8 refs

  15. Echolocation in sympatric Peale's dolphins (Lagenorhynchus australis) and Commerson's dolphins (Cephalorhynchus commersonii) producing narrow-bandhigh-frequency clicks

    DEFF Research Database (Denmark)

    Kyhn, Line Anker; Jensen, Frants Havmand; Beedholm, Kristian

    2010-01-01

    -element hydrophone array from wild Peale's (Lagenorhynchus australis) and Commerson's (Cephalorhynchus commersonii) dolphins off the Falkland Islands. The centroid frequency was different between Commerson's (133±2kHz) and Peale's (129±3kHz) dolphins. The r.m.s. bandwidth was 12±3kHz for both species. The source...... level was higher for Peale's dolphin (185±6dB re 1 uPa p.-p.) than for Commerson's(177±5 dB re 1 uPa p.-p.). The mean directivity indexes were 25dB for both species. The relatively low source levels in combination with the high directivity index may be an adaptation to reduce clutter when foraging...

  16. A simulation of temperature influence on echolocation click beams of the Indo-Pacific humpback dolphin (Sousa chinensis).

    Science.gov (United States)

    Song, Zhongchang; Zhang, Yu; Wang, Xianyan; Wei, Chong

    2017-10-01

    A finite element method was used to investigate the temperature influence on sound beams of the Indo-Pacific humpback dolphin. The numerical models of a dolphin, which originated from previous computed tomography (CT) scanning and physical measurement results, were used to investigate sound beam patterns of the dolphin in temperatures from 21 °C to 39 °C, in increments of 2 °C. The -3 dB beam widths across the temperatures ranged from 9.3° to 12.6°, and main beam angle ranged from 4.7° to 7.2° for these temperatures. The subsequent simulation suggested that the dolphin's sound beam patterns, side lobes in particular, were influenced by temperature.

  17. Attitudes towards wind power development in Denmark

    DEFF Research Database (Denmark)

    Ladenburg, Jacob

    The present paper analyses the attitudes towards existing and future land-based turbines and off-shore wind farms. The analysis is carried out using a probit model to elicit systematic characteristics determining the attitude of the population. The analyses show that off-shore development...... is preferred to land based development, which indicates that the wind power development should be taken off-shore. But, the results also point out that the land-based opportunities for wind power development are not exhausted. On a more detailed level, the results denote that the attitude towards both land...... based and off-shore wind power vary with age of the respondents and experience with wind turbines. Younger respondents are more positive towards wind power than older respondents, pointing towards an increase in acceptance in the future. The attitude was also found to covariate negatively...

  18. The MEUST deep sea infrastructure in the Toulon site

    Directory of Open Access Journals (Sweden)

    Lamare Patrick

    2016-01-01

    Full Text Available The MEUST infrastructure (Mediterranean Eurocentre for Underwater Sciences and Technologies is a permanent deep sea cabled infrastructure currently being deployed off shore of Toulon, France. The design and the status of the infrastructure are presented.

  19. Ultimate loading of wind turbines

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Ronold, K.; Ejsing Jørgensen, Hans

    1999-01-01

    An extreme loading study has been conducted comprising a general wind climate analysis as well as a wind turbine reliability study. In the wind climate analysis, the distribution of the (horizontal) turbulence standard deviation, conditioned on the meanwind speed, has been approximated by fitting......, a design turbulence intensity for off-shore application is proposed which, in the IEC code framework, is applicable for extreme as well as for fatigue loaddetermination. In order to establish a rational method to analyse wind turbine components with respect to failure in ultimate loading, and in addition...... a three parameter Weibull distribution to the measured on-shore and off-shore data for wind speed variations. Specific recommendations on off-shore design turbulence intensities are lacking in the presentIEC-code. Based on the present analysis of the off-shore wind climate on two shallow water sites...

  20. 78 FR 38030 - Application for Final Commitment for a Long-Term Loan or Financial Guarantee in Excess of $100...

    Science.gov (United States)

    2013-06-25

    ... of U.S. goods and services to be used in Pemex's on- and off-shore oil and gas exploration and.... Guarantor(s): Pemex Exploracion y Produccion; Pemex Refinacion; Pemex Gas y Petroquimica Basica. Description...

  1. utilizing the tool of gis in oil spill management - a case study of etche

    African Journals Online (AJOL)

    xtz

    Data were collected and imported into GIS environment for analysis using ArcInfo ... identified as the major oil spill distributor. Out of total .... terrestrial traffic accidents, oil well blowout, off shore and ... networks as linear features, and the major.

  2. Gas Sorption, Diffusion and Permeation in a Polymer of Intrinsic Microporosity (PIM-7)

    KAUST Repository

    Alaslai, Nasser Y.

    2013-01-01

    consumption. Membrane technology is a relatively new separation process for natural gas purification with large growth potential, specifically for off-shore applications. The economics of any membrane separation process depend primarily on the intrinsic gas

  3. Coral and artificial reef shape files, Broward County, Florida, (NODC Accession 0000244)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coral reef and artificial reef location shape files and accompanying table files for reefs located off shore of Broward County, Florida. Accompanying "attribute"...

  4. Offshoring in the automobile ancillary sector. Who competes with its production plants?; Deslocalizacion en el sector auxiliar del automovil. Con quien compite su planta de produccion?

    Energy Technology Data Exchange (ETDEWEB)

    Lampon, J. F.; Vazquez, X. H.; Garcia-Vazquez, J. M.

    2010-07-01

    The paper addresses the causes of off shoring in the Spanish car industry. It compares the internal rivalry between European subsidiaries of the same multinational with the external rivalry stemming from other competitors located in Spain. Our analysis shows two important results: firstly, that productivity is more important than profitability in off shoring decisions; and second, that these differences are more evident for internal rivalry than for external rivalry. (Author) 21 refs.

  5. Maximising the commercial value of wind energy through forecasting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The aim of this project, initiated by the DTI, was to advise the electricity industry on the possibility of using weather forecasting to improve the commercial position of both inland and off-shore wind farms under the New Electricity Trading Arrangements (NETA) and to develop appropriate strategies for the use of forecasting. The work has clearly shown that, by using forecasting, wind generators can make money on the Short-Term Power Exchange, increasing their revenue over and above that achieved in the cash-out market. For inland sites, the average annual increased earnings are estimated around 5.8%, rising to 7.5% off-shore. The forecast value methodology developed by the Meteorological Office during the project has proven to be a valuable tool for analysing wind farm trading under NETA. The methodology has the potential to be used by wind farm operators and suppliers wishing to actively trade wind on the Short-Term Power Exchange. It is recommended that further verification of the methodology and development for active use is required. Specifically, a lack of 'true' off-shore wind data has been identified. It appears that off-shore wind farms stand to gain most from forecasting and the report calls for off-shore wind observation data to be made available to allow better verification of the off-shore forecasting models to be undertaken. (author)

  6. New discoveries on the ecology and echolocation of the heart-nosed bat Cardioderma cor with a contribution to the phylogeny of Megadermatidae

    Czech Academy of Sciences Publication Activity Database

    Kaňuch, P.; Aghová, Tatiana; Meheretu, Y.; Šumbera, R.; Bryja, Josef

    2015-01-01

    Roč. 50, č. 1 (2015), s. 53-57 ISSN 1562-7020 R&D Projects: GA ČR GAP506/10/0983 Institutional support: RVO:68081766 Keywords : acoustics * Chiroptera * eastern Africa * evolutionary radiation * roosts Subject RIV: EG - Zoology Impact factor: 0.739, year: 2015 http://www.tandfonline.com/doi/abs/10.1080/15627020.2015.1021711

  7. Exergetic analysis in petroleum primary separation plants; Analise exergetica em plantas de separacao primaria de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ghiorzi, Telmo Machado

    1997-07-01

    This dissertation presents a method for evaluate the efficiency of primary petroleum separation plants off-shore, using the concept of exergy. This concept is presented as a thermodynamic property and one shows how to calculate its value. A bibliographic revision is done, as well as, the necessary adaptations and considerations foe exergy application on off-shore plants: It is presented a way to evaluate efficiency on plants which part of the products is used as the drive-force of the process and it is presented the exergy calculation for mixtures, through departure functions. This calculation deserves special attention due to Equilibrium-Liquid-Vapour behavior of the mixtures when brought to ambient conditions. Some hypothetical cases, carried out using the Process Simulator HYSIM, are analyzed. The conclusions and recommendations are related to design and operation of off-shore plants and perspectives to follow on the subject exergy and the petroleum industry. (author)

  8. Convergences in the diversification of bats

    Directory of Open Access Journals (Sweden)

    M. Brock FENTON

    2010-08-01

    Full Text Available Twenty-five characters or suites of characters from bats are considered in light of changes in bat classification. The characters include some associated with flower-visiting (two, echolocation (12, roosting (six, reproduction (two and three are of unknown adaptive function. In both the 1998 and 2006 classifications of bats into suborders (Megachiroptera and Microchiroptera versus Yinpterochiroptera and Yangochiroptera, respectively, some convergences between suborders are the same (e.g., foliage roosting, tent building, but others associated with echolocation differ substantially. In the 1998 phylogeny convergences associated with echolocation (high duty cycle echolocation, nasal emission of echolocation calls occurred among the Microchiroptera. In the 2006 phylogeny, they occur between Yinpterochiroptera and Yangochiroptera. While some traits apparently arose independently in two suborders (e.g., foliage-roosting, tent building, low intensity echolocation calls, noseleafs, nasal emission of echolocation calls, high duty cycle echolocation behaviour, others appear to have been ancestral (roosting in narrow spaces, laryngeal echolocation, stylohyal-tympanic contact, oral emission of echolocation calls, and small litter size. A narrow profile through the chest is typical of bats reflecting the thoracic skeleton. This feature suggests that the ancestors of bats spent the day in small crevices. Features associated with laryngeal echolocation appear to be ancestral, suggesting that echolocation evolved early in bats but was subsequently lost in one yinpterochiropteran lineage [Current Zoology 56 (4: 454–468, 2010].

  9. Multi-megawatt wind-power installations call for new, high-performance solutions

    International Nuclear Information System (INIS)

    2004-01-01

    This article discusses the development of increasingly powerful and profitable wind-energy installations for off-shore, on-shore and refurbishment sites. In particular, the rapid development of megawatt-class units is discussed. The latest products of various companies with rotor diameters of up to 120 metres and with power ratings of up to 5 MW are looked at and commented on. The innovations needed for the reduction of weight and the extreme demands placed on gearing systems are discussed. Also, the growing markets for wind energy installations in Europe and the United States are discussed and plans for new off-shore wind parks are looked at

  10. Wind Energy: Trends And Enabling Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Devabhaktuni, Vijay; Alam, Mansoor; Boyapati, Premchand; Chandna, Pankaj; Kumar, Ashok; Lack, Lewis; Nims, Douglas; Wang, Lingfeng

    2010-09-15

    With attention now focused on the damaging impact of greenhouse gases, wind energy is rapidly emerging as a low carbon, resource efficient, cost-effective sustainable technology in many parts of the world. Despite higher economic costs, offshore appears to be the next big step in wind energy development alternative because of the space scarcity for installation of onshore wind turbine. This paper presents the importance of off-shore wind energy, the wind farm layout design, the off-shore wind turbine technological developments, the role of sensors and the smart grid, and the challenges and future trends of wind energy.

  11. Spatial distribution of seepage at a flow-through lake: Lake Hampen, Western Denmark

    DEFF Research Database (Denmark)

    Kidmose, Jacob Baarstrøm; Engesgaard, Peter Knudegaard; Nilsson, Bertel

    2011-01-01

    recharge patiern of the lake and relating these to the geologic history of the lake. Recharge of the surrounding aquifer by lake water occurs off shore in a narrow zone, as measured from lake–groundwater gradients. A 33-m-deep d18O profi le at the recharge side shows a lake d18O plume at depths...... that corroborates the interpretation of lake water recharging off shore and moving down gradient. Inclusion of lake bed heterogeneity in the model improved the comparison of simulated and observed discharge to the lake. The apparent age of the discharging groundwater to the lake was determined by CFCs, resulting...

  12. Deposits of naturally occurring radioactivity in production of oil and natural gas

    International Nuclear Information System (INIS)

    Strand, T.; Lysebo, I.; Kristensen, D.; Birovljev, A.

    1997-01-01

    Deposits of naturally occurring radioactive materials is an increasing problem in Norwegian oil and gas production. Activity concentration in solid-state samples and production water, and doses to workers involved in different operations off-shore, have been measured. The report also includes a discussion of different methods of monitoring and alternatives for final disposal of wastes. 154 refs

  13. Report to Congress on Sustainable Ranges

    Science.gov (United States)

    2014-02-01

    high capacity transmission lines, solar arrays, and geothermal 4 | 2014 Sustainable Ranges Report February 2014 Chapter 1: Military Service... geothermal power and associated transmission infrastructure both on- and off-shore will require close attention to ensure the Marine Corps’ access...Weapons Systems Training Facility (NWSTF) Boardman; offshore wind development proposed south of Pearl Harbor, HI, NAWC China Lake, CA/Nevada Test

  14. Forecasting Water Waves and Currents: A Space-time Approach

    NARCIS (Netherlands)

    Ambati, V.R.

    2008-01-01

    Forecasting water waves and currents in near shore and off shore regions of the seas and oceans is essential to maintain and protect our environment and man made structures. In wave hydrodynamics, waves can be classified as shallow and deep water waves based on its water depth. The mathematical

  15. Characterization of aerodynamic performance of vertical axis wind turbines : impact of operational parameters

    NARCIS (Netherlands)

    Rezaeiha, Abdolrahim; Montazeri, Hamid; Blocken, Bert

    2018-01-01

    Vertical axis wind turbines (VAWTs) have received growing interest for off-shore application and in the urban environments mainly due to their omni-directional capability, scalability, robustness, low noise and costs. However, their aerodynamic performance is still not comparable with their

  16. Learning from Employee Communication during Technological Change

    Science.gov (United States)

    Law, Sweety

    2009-01-01

    Purpose: The purpose of this research is to examine stories of and by employees as they implemented a transformative organizational change, involving outsourcing, off-shoring, and the make-over induced by technology. Design/methodology/approach: Three types of data were analyzed--organizational documents, responses to oral and written questions,…

  17. Excursion probabilities of non-homogeneous Gaussian scalar fields based on maxima considerations

    DEFF Research Database (Denmark)

    Nielsen, Michael Havbro Faber; Rackwitz, R.

    1988-01-01

    Many uncertain natural or technical phenomena are most realistically described by random fields. A typical example of a random field is the load effect in a floor slab which is loaded by a spatially distributed gravity load. Other examples of random fields include the sea-level around off-shore p...

  18. Structural health monitoring with a wireless vibration sensor network

    NARCIS (Netherlands)

    Basten, T.G.H.; Sas, P; Schiphorst, F.B.A.; Jonckheere, S.; Moens, D.

    2012-01-01

    Advanced maintenance strategies for infrastructure assets such as bridges or off shore wind turbines require actual and reliable information of the maintenance status. Structural health monitoring based on vibration sensing can help in supplying the input needed for structural health monitoring

  19. Imposex in the common whelk, Buccinum undatum

    NARCIS (Netherlands)

    Mensink, B.P.

    1999-01-01

    The research described in this thesis concerned the perhaps best known and studied common gastropod from the open North Sea of which only limited information was available. With the present research more insight has been obtained concerning this long-lived, off-shore snail species, which

  20. The DTU15 MSS (Mean Sea Surface) and DTU15LAT (Lowest Astronomical Tide) reference surface

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Stenseng, Lars; Piccioni, Gaia

    in the Arctic Ocean for DTU10MSS and DTU13MSS.A new reference surface for off-shore vertical referencing is introduced. This is called the DTU15LAT.The surface is derived from the DTU15MSS and the DTU10 Global ocean tide to give a 19 year Lowest Astronomical Tide referenced to either the Mean sea surface...

  1. The electrical connection of offshore windparks - technology and investment costs

    International Nuclear Information System (INIS)

    Busch, R.; Schultz, W.; Unger, C.; Diedrichs, V.

    1996-01-01

    In order to reach an acceptable cost level for wind energy generated in off-shore wind farms, the consideration of the electrical grid connection is much more important than for on-shore sites. This connection was investigated under technical as well as financial aspects leading to different concepts for different sizes of windfarms. (Author)

  2. Using Digital Acoustic Recording Tags to Detect Marine Mammals on Navy Ranges and Study their Responses to Naval Sonar

    Science.gov (United States)

    2011-02-01

    densirostris) off the coast of El Hierro in the Canary Islands. A tag was deployed with relative ease on an adult beaked whale which proceeded to carry it for...located off-shore of El Hierro by chance. On examination, we found that water ingress had again caused failure of the recording circuit early in the

  3. Contract mechanism for coordinating operational and marketing decisions in a supply chain : Models & analysis

    NARCIS (Netherlands)

    Nalla, V.R.

    2008-01-01

    Companies can no longer perceive themselves as stand-alone entities in the business environment. As a result of major trends such as Globalization, Outsourcing and Off-shoring, companies have more and more begun to perceive themselves as part of a chain (or network) of companies. With the increased

  4. 22 CFR 124.3 - Exports of technical data in furtherance of an agreement.

    Science.gov (United States)

    2010-04-01

    ... approved in writing by the Directorate of Defense Trade Controls (DDTC) and the technical data does not... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Exports of technical data in furtherance of an... REGULATIONS AGREEMENTS, OFF-SHORE PROCUREMENT AND OTHER DEFENSE SERVICES § 124.3 Exports of technical data in...

  5. Cross-shelf investigation of coral reef cryptic benthic organisms reveals diversity patterns of the hidden majority

    KAUST Repository

    Pearman, John K.; Leray, M.; Villalobos, R.; Machida, R. J.; Berumen, Michael L.; Knowlton, N.; Carvalho, Susana

    2018-01-01

    (ARMS) and amplicon sequencing methodologies, targeting mitochondrial cytochrome oxidase I and 18S rRNA genes, to investigate changes in the cryptic reef biodiversity. ARMS, deployed at 11 sites across a near- to off-shore gradient in the Red Sea were

  6. A Cross-Cultural Investigation of Human Performance Technology Interventions

    Science.gov (United States)

    Vadivelu, Ramaswamy N.

    2010-01-01

    Human Performance Technology (HPT) is a field of practice that has evolved from advancements in organizational development, instructional design, strategic human resource management and cognitive psychology. As globalization and trends like outsourcing and off-shoring start to dominate the way organizations grow, HPT practitioners are managing the…

  7. Rahapesu andmebüroo uurib Ühispanga juhtumit / Inno Tähismaa

    Index Scriptorium Estoniae

    Tähismaa, Inno, 1970-

    2004-01-01

    Politsei rahapesu andmebüroo juhi Arnold Tenusaare kinnitusel alustatakse Ühispanga asepresidendi Lembit Kitteriga seotud off-shore firma Patent Developments Ltd. juhtumi uurimist, kus 1997. aastal firma pangaarvelt sularaha väljavõtmisel võis olla tegemist allkirja võltsimise ja rahapesuga

  8. Assessing 21st Century Skills: Summary of a Workshop

    Science.gov (United States)

    Koenig, Judith Anderson

    2011-01-01

    The routine jobs of yesterday are being replaced by technology and/or shipped off-shore. In their place, job categories that require knowledge management, abstract reasoning, and personal services seem to be growing. The modern workplace requires workers to have broad cognitive and affective skills. Often referred to as "21st century…

  9. 2211-IJBCS-Article-Gidéon Wole Olakunle

    African Journals Online (AJOL)

    admin

    gives baseline information about the delphinid community sighted off-shore Lagos, Nigeria. ... Sighting rate for delphinids was obtained by processing visual data obtained at ... Keywords: Sightings, Oceanic dolphins, abundance, species richness, behaviour, Nigeria. .... is likely to lead to an under-recording of deep.

  10. effect of crude oil extracts on early stages of african catfish

    African Journals Online (AJOL)

    Admin

    Nigerian Bonny light crude oil and Exxon Mobil Oso off-shore condensate during a ... of Oso condensate extract when larval integument was damaged. It is ... Spills of oil condensate from Oso Exxon Mobil Oil rig readily enter the .... compounds are extracted from oil films in natural .... Resources and Fishing Rome, 9-13 Dec.

  11. Urban Wind Energy - State of the Art 2009

    DEFF Research Database (Denmark)

    Beller, Christina

    Wind energy in urban areas is a new area and a rather blank page concerning design criteria, aesthetics, concepts, minimizing costs etc. Even though the potential energy in the flow is much higher on the country side or off-shore, the erection of wind turbines in urban areas is carried out and also...

  12. static analysis of circular cylindrical shell under hydrostatic and ring

    African Journals Online (AJOL)

    DEPT OF AGRICULTURAL ENGINEERING

    (Golzan et al, 2008). Circular cylindrical shells are used in a large variety of civil engineering structures, e.g. off-shore platforms, chimneys, silos, pipelines, bridge arches or wind turbine towers (Winterstetter et al, 2002). This work is concerned with the analysis of circular cylindri- cal shell subjected to hydrostatic pressure in.

  13. Closing the Gap--Information Systems Curriculum and Changing Global Market

    Science.gov (United States)

    Henson, Kerry; Kamal, Mustafa

    2010-01-01

    The power of outsourcing basic computing technology such as computer programming, database design, customer service operations and system development, to mention a few have changed the conditions of employment in IT. Many of the projects that went off-shore did not perform well due to failure to consider important factors in business dimensions.

  14. Malaysian Private Education Quality: Application of SERVQUAL Model

    Science.gov (United States)

    Vaz, Anthony; Mansori, Shaheen

    2013-01-01

    Intense competition among existing private education providers and the Malaysian government's relaxation of regulations for allowing international universities to open off shore campuses in Malaysia, have forced companies in the education industry to develop strategies which can help them to make their existing students satisfied and keep them…

  15. Deposits of naturally occurring radioactivity in production of oil and natural gas; Radioaktive avleiringer i olje- og gassproduksjon

    Energy Technology Data Exchange (ETDEWEB)

    Strand, T; Lysebo, I; Kristensen, D; Birovljev, A

    1997-01-01

    Deposits of naturally occurring radioactive materials is an increasing problem in Norwegian oil and gas production. Activity concentration in solid-state samples and production water, and doses to workers involved in different operations off-shore, have been measured. The report also includes a discussion of different methods of monitoring and alternatives for final disposal of wastes. 154 refs.

  16. Proceedings of the NKS/SOS-2 seminar on risk informed principles

    International Nuclear Information System (INIS)

    Pulkkinen, U.; Simola, K.

    1999-09-01

    The aim of this NKS/SOS-2 seminar was to present the status and plans of applications of Risk Informed Principles both by nuclear authorities and industry in Finland and Sweden. Furthermore, views from the off-shore industry were presented. (EHS)

  17. Low specific activity scale in the oil industry

    International Nuclear Information System (INIS)

    1991-01-01

    The NRPB present an illustrated fold-out leaflet in the At-a-glance series, for members of the oil industry, indicating the type of radioactivity to be met during off-shore drilling, possible hazards, doses, and precautions and procedures to be undertaken by workers. (author)

  18. Soil and Groundwater Characteristics of a Legacy Spill Site AKURO ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    significant environmental consequences that occur. ... increasing production of crude oil and discovery of ... occurred in the mangrove swamps zones and near off shores areas of the Niger Delta which was shown in ... Assessment of the spill site had been carried out ... data and risks about the site, an intrusive ground.

  19. Automatic Data Collection Design for Real-time Detection of Oil

    African Journals Online (AJOL)

    ES Obe

    Niger Delta region in Nigeria where crude oil is produced both on-shored and off- ... National Emergency Management Agency (NEMA) and involves huge ... mangrove, thick forest and off-shore areas of the Nation offers the much ... oil have been spilled into the environment ... linking some 275 flow stations to various.

  20. The Davis Strait

    DEFF Research Database (Denmark)

    The Bureau of Minerals and Petroleum (BMP) is planning for further exclusive licences for exploration and exploitation of hydrocarbons in the Greenland off shore areas of Davis Strait. To support the decision process BMP has asked DCE - Danish Centre for Environment and Energy and the Greenland I...

  1. Remote sensoring for an offshore windfarm maintenance system

    NARCIS (Netherlands)

    Leon Morales, C.F.; Malsen, J. van

    2011-01-01

    In the current offshore wind energy market high cost efficiency is a major factor. While budgets become more limited, the demands for the structures are constantly increasing. Wind turbine park owners (and operators) now request a lifetime of 25 years or more for their off shore structures. The

  2. Atlantic update, July 1986--June 1990: Outer Continental Shelf oil and gas activities

    Energy Technology Data Exchange (ETDEWEB)

    Karpas, R.M.; Gould, G.J.

    1990-10-01

    This report describes outer continental shelf oil and gas activities in the Atlantic Region. This edition of the Atlantic Update includes an overview of the Mid-Atlantic Planning Area and a summary of the Manteo Prospect off-shore North Carolina. 6 figs., 8 tabs.

  3. Effect of crude oil extracts on early stages of African catfish ...

    African Journals Online (AJOL)

    Eggs and larvae of Heterobranchus longifilis were exposed to extracts of different concentrations of Nigerian Bonny light crude oil and Exxon Mobil Oso off-shore condensate during a comparative toxicity experiment carried out in the Institute of Oceanography Fish Farm, University of Calabar, Nigeria. Petroleum ...

  4. Modelling of accidental releases from a high pressure CO2 pipelines

    NARCIS (Netherlands)

    Molag, M.; Dam, C.

    2011-01-01

    In the near future large quantities of CO2 will be transported over a large distance from Carbon dioxide Capture plants to onshore and off-shore underground Storage (CCS) sites. The risk assessments for the existing CO2 pipelines show distances to harmful threshold concentrations from 1 to 7.2 km.

  5. Design study of 10 kW superconducting generator for wind turbine applications

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen

    2009-01-01

    = 1 Tesla to be similar to the performance of permanent magnets and to represent a layout, which can be scaled up in future off-shore wind turbines. The proposed generator is a 8 pole synchronous machine based on race-track coils of high temperature superconducting tapes and an air cored copper stator...

  6. Selecting Suitable Sites for Wind Energy Development in Ghana*

    African Journals Online (AJOL)

    Michae O. Mensah

    2016-06-01

    Jun 1, 2016 ... Ghana's wind power potential both on-shore and off-shore. ..... such as forest and game reserves, tourist sites, etc. (iv) Siting in lakes is restricted. (v) Slopes greater than 30° ... Atlantic coastline that stretches 560 km along the.

  7. Promoting International Energy Security: Volume 4, The Gulf of Guinea

    Science.gov (United States)

    2012-01-01

    water production of the United States, Brazil , and Angola (Sandrea and Sandrea, 2010). Moreover, the deep off- shore area is likely to continue to...these skills. The Niger Delta is approximately 70,000 km2 of rivers, mangroves , jungles, and swamps. The oil infrastructure is similarly expansive

  8. Simulation and Optimization of an Innovative Dual Mixed Component Refrigerant Cycle (DMRC) for Natural Gas Offshore Liquefaction Plants

    International Nuclear Information System (INIS)

    SHAHBA, L.A.; Fahmy, M.F.M.

    2004-01-01

    Simulation and optimization of an innovative liquefaction process used for the LNG production , namely the Dual Mixed Refrigerant Process (DMRC) has been conducted using the HYSYS simulator .This new process is especially suitable for off shore natural gas liquefaction plants. A numerical optimization technique has been used to determine the optimum conditions for Egyptian natural gas feed source. The investigation of the effect of different compositions of the Mixed refrigerants used was conducted. Meanwhile, the investigation of the influence of the temperature of cooling water used was conducted. The best optimum conditions for the DMRC process were determined .The optimum results achieved for the DMRC process revealed that the DMRC process can be successfully applied as a promising technique for off shore natural gas liquefaction plants

  9. Strategic involvement of information and communication technologies in outsourcing

    DEFF Research Database (Denmark)

    Perunovic, Zoran; Christoffersen, Mads

    2005-01-01

    outsourcing have significant role in innovating business models of companies. However, the technological islands of application are not converging, at least not with desirable pace. Future off-shore outsourcing will comprehend more R&D activities, and spread throughout the whole business process. Existence...... of integrated IT solutions will stimulate, while documenting and standardising business processes will further fructify ICT's utilisation in outsourcing. Research limitations Limited number of companies makes generalisation difficult. There is a certain number of factors that influence success of off......Purpose To portrait the utilisation of information and communication technology in off-shore outsourcing and raise questions for debate, hypotheses for verifications, and ideas for the improvement. Design/methodology/approach An explorative qualitative study with a research framework designed...

  10. Research and development of utilization system of photovoltaic power generation. R and D of stand-alone power system (for marine use)

    Energy Technology Data Exchange (ETDEWEB)

    1986-08-01

    This is an annual report for 1985 for NEDO -contracted project. The project aims at establishing an efficient, stable power generating solar cell technology and developing a power supply system for the ocean development. In order to install an independent off-shore power supply system for the marine ranch at Kamiura, Oita Prefecture, a frame berge was constructed on the Tsuinoura pier and an annularly arranged disc type solar cell with the center tapered at 4 % in an umbrella shape towards outside. Designed capacity was 10 KWp maximum output, and total 11 KVA (1 KVA at heavy duty load and 10 KVA at sun-shining load). The power source system consists of units for solar cell, power storage, control, orthogonal conversion, and of various loads. The system can make a normal observation by a wireless data transmission from off-shore onto the ground. (2 figs, 4 tabs)

  11. Marine protected areas in Costa Rica: How do artisanal fishers respond?

    Science.gov (United States)

    Madrigal-Ballestero, Róger; Albers, Heidi J; Capitán, Tabaré; Salas, Ariana

    2017-11-01

    Costa Rica is considering expanding their marine protected areas (MPAs) to conserve marine resources. Due to the importance of households' responses to an MPA in defining the MPA's ecological and economic outcomes, this paper uses an economic decision framework to interpret data from near-MPA household surveys to inform this policy discussion. The model and data suggest that the impact of expanding MPAs relies on levels of enforcement and on-shore wages. If larger near-shore MPAs can produce high wages through increased tourism, MPA expansions could provide ecological benefits with low burdens to communities. Due to distance costs and gear investments, however, MPAs farther off-shore may place high burdens on off-shore fishers.

  12. The parameters of free play of light drilling installations with varying configuration of the floating base

    Energy Technology Data Exchange (ETDEWEB)

    Putov, B.I.

    1980-01-01

    A reduction in the free play may be achieved through the rational selection of the basic dimensions of the body elements, the disposition of the bodies one relative to the other and by the use of various means for passive stabilization. In the design of MPBU not only the mean values of the free play parameters, which characterize a floating base from the point of view of the time people stay on it, must be available, but also the maximal possible values of the parameters with one and the same wave state, which determine the safety of the operation of the drilling equipment. Studies in installations of various standard off shore drilling rigs showed that the mean values of the free play parameters for all off shore drilling rigs with wave heights from 0.8 to 1.2 meters are half the maximal values.

  13. Working group 4a: Regional aspects. Nuclear power plants siting in the dutch speaking part of the country

    International Nuclear Information System (INIS)

    Willems, M.; Medart, R.; Vanneste, O.

    1976-01-01

    The problems due to nuclear plant siting in the northern region of Belgium are reviewed with an emphasis on economical, environmental and esthetical aspects. Three types of sitings were analysed: inland, coastal and off-shore. For the in-land siting, Doel, where already two units are in operation (780 MWe) and a third in construction (900 MWe), is supposed to be able to receive a fourth unit of 1000 MWe. The coastal siting is practically impossible for two reasons: the lack of cooling water when a coastal inland region of 5 km is considered and the strong density of tourists on the 66 km coast. For artificial island siting the different aspects are considered: type of soil, marine environment, construction factors, security, construction time, costs, etc. A comparative study for 9 off-shore sites is presented. (A.F.)

  14. Satellite SAR wind resource mapping in China (SAR-China)

    Energy Technology Data Exchange (ETDEWEB)

    Badger, M.

    2009-07-15

    The project 'Off-Shore Wind Energy Resource Assessment and Feasibility Study of Off-Shore Wind Farm Development in China' is funded by the EU-China Energy and Environment Programme (EEP) and runs for one year (August 2008 - August 2009). The project is lead by the China Meteorological Administration (CMA) and supported by SgurrEnergy Ltd. Risoe National Laboratory for Sustainable Energy at the Technical University of Denmark (Risoe DTU) has been commissioned to perform a satellite based wind resource analysis as part of the project. The objective of this analysis is to map the wind resource offshore at a high spatial resolution (1 km). The detailed wind resource maps will be used, in combination with other data sets, for an assessment of potential sites for offshore wind farm development along the coastline from Fujian to Shandong in China. (au)

  15. What ears do for bats: a comparative study of pinna sound pressure transformation in chiroptera.

    Science.gov (United States)

    Obrist, M K; Fenton, M B; Eger, J L; Schlegel, P A

    1993-07-01

    Using a moveable loudspeaker and an implanted microphone, we studied the sound pressure transformation of the external ears of 47 species of bats from 13 families. We compared pinna gain, directionality of hearing and interaural intensity differences (IID) in echolocating and non-echolocating bats, in species using different echolocation strategies and in species that depend upon prey-generated sounds to locate their targets. In the Pteropodidae, two echolocating species had slightly higher directionality than a non-echolocating species. The ears of phyllostomid and vespertilionid species showed moderate directionality. In the Mormoopidae, the ear directionality of Pteronotus parnellii clearly matched the dominant spectral component of its echolocation calls, unlike the situation in three other species. Species in the Emballonuridae, Molossidae, Rhinopomatidae and two vespertilionids that use narrow-band search-phase echolocation calls showed increasingly sharp tuning of the pinna to the main frequency of their signals. Similar tuning was most evident in Hipposideridae and Rhinolophidae, species specialized for flutter detection via Doppler-shifted echoes of high-duty-cycle narrow-band signals. The large pinnae of bats that use prey-generated sounds to find their targets supply high sound pressure gain at lower frequencies. Increasing domination of a narrow spectral band in echolocation is reflected in the passive acoustic properties of the external ears (sharper directionality). The importance of IIDs for lateralization and horizontal localization is discussed by comparing the behavioural directional performance of bats with their bioacoustical features.

  16. Comparative inner ear transcriptome analysis between the Rickett's big-footed bats (Myotis ricketti) and the greater short-nosed fruit bats (Cynopterus sphinx).

    Science.gov (United States)

    Dong, Dong; Lei, Ming; Liu, Yang; Zhang, Shuyi

    2013-12-23

    Bats have aroused great interests of researchers for the sake of their advanced echolocation system. However, this highly specialized trait is not characteristic of Old World fruit bats. To comprehensively explore the underlying molecular basis between echolocating and non-echolocating bats, we employed a sequence-based approach to compare the inner ear expression difference between the Rickett's big-footed bat (Myotis ricketti, echolocating bat) and the Greater short-nosed fruit bat (Cynopterus sphinx, non-echolocating bat). De novo sequence assemblies were developed for both species. The results showed that the biological implications of up-regulated genes in M. ricketti were significantly over-represented in biological process categories such as 'cochlea morphogenesis', 'inner ear morphogenesis' and 'sensory perception of sound', which are consistent with the inner ear morphological and physiological differentiation between the two bat species. Moreover, the expression of TMC1 gene confirmed its important function in echolocating bats. Our work presents the first transcriptome comparison between echolocating and non-echolocating bats, and provides information about the genetic basis of their distinct hearing traits.

  17. Oilbirds

    DEFF Research Database (Denmark)

    Brinkløv, Signe; Warrant, Eric

    2017-01-01

    A Quick guide to oilbirds: nocturnal birds found only in Neotropical rainforests that, rather like many bat species, live in caves where they use echolocation for orientation.......A Quick guide to oilbirds: nocturnal birds found only in Neotropical rainforests that, rather like many bat species, live in caves where they use echolocation for orientation....

  18. The stable stiffness triangle - drained sand during deformation cycles

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2017-01-01

    Cyclic, drained sand stiffness was observed using the Danish triaxial appa- ratus. New, deformation dependant soil property (the stable stiffness triangle) was detected. Using the the stable stiffness triangle, secant stiffness of drained sand was plausible to predict (and control) even during ir...... findings can find application in off-shore, seismic and other engi- neering practice, or inspire new branches of research and modelling wherever dynamic, cyclic or transient loaded sand is encountered....

  19. Non-Technical Skills (NTS) for enhancing patient safety: achievements and future directions

    OpenAIRE

    Kodate, Naonori; Ross, Anthony; Anderson, Janet E.; Flin, R.

    2012-01-01

    Problems in team communication and decision making have been implicated in accidents in high risk industries such as aviation, off shore oil processing, nuclear power generation. Recognition of the role that breakdowns in communication and teamwork play in patient safety incidents has led to a plethora of studies in the area of what has come to be widely known as non-technical skills (NTS); a term initially used in European aviation (1). This has led to increasing interest in i...

  20. Valorizzazione e qualificazione di prodotti della pesca ed acquacoltura

    OpenAIRE

    Olivieri, Vincenzo

    2010-01-01

    La ricerca ha valutato parametri sensoriali, fisici, chimici e microbiologici di orata (Sparus aurata) durante la conservazione in MAP. Campioni di pesce, ottenuti da 2 allevamenti off-shore situati rispettivamente nel Tirreno Settentrionale e nel Tirreno meridionale, sono stati analizzati dopo 1, 5, 7, 12, 15 e 19 giorni di stoccaggio. La valutazione sensoriale è stata effettuata utilizzando il Quality Index Method (QIM). Le analisi di tipo fisico, chimico e microbiologico sono state esegu...

  1. Theoretical and practical aspects of risk management in contemporary global supply chains

    Directory of Open Access Journals (Sweden)

    2010-09-01

    Full Text Available Globalization, off-shoring, outsourcing and pressure on cost reduction influence on the increasing complexity of supply chains and lead to higher risk. This may concern supplies, deliveries, manufacturing and transportation. Companies which source from distant countries have to implement risk management system. Examples of companies which use such systems prove, that it is possible to reduce uncertainty. Results concern shorter lead times, better quality and accepted cost level.

  2. Renewable Energy Country Attractiveness Indices

    International Nuclear Information System (INIS)

    2011-02-01

    Since 2003 Ernst and Young team has been releasing quarterly data that ranks national renewable energy markets, and their suitability for individual technologies. The Country Attractiveness Indices now track the relative attractiveness of 30 countries' renewable energy markets across a selection of technologies each quarter. The Renewable Energy Country Attractiveness Indices publication scores and comments on various technologies, including: on-shore wind, off-shore wind, solar PV, solar CSP, biomass, and geothermal.

  3. Countering Russian Active Measures

    Science.gov (United States)

    2018-04-16

    information laundering has proven effective in several occasions.20 In 2016, Russian social media actors circulated a fake news story about the...Soviet Union, individuals in positions of power funneled communist party financial resources to off-shore bank accounts and later used this money to...international offshore banking industry, they [the current oligarchs] stole money that belonged to the Russian state, took it abroad for safety

  4. Getting the oil to the shore

    Energy Technology Data Exchange (ETDEWEB)

    Menin, J.A.; Meuter, P.

    2006-03-15

    Conveying highly corrosive fluids - hot water dissolved in salt and sulfide - is just one aspect of getting oil from the field to the shore. Brazilian oil company Petrobras had a requirement for high pressure pumps that could handle high viscosity fluids at its Campos off-shore oil field and be easily maintained. Joao Alberto Menin, Paul Meuter explains how Sulzer Pumps rose to the challenge. (author)

  5. Some atmospheric dispersion, wind and temperature statistics from Jervis Bay, Australian Capital Territory 1972 to 1974

    International Nuclear Information System (INIS)

    Clark, G.H.

    1985-07-01

    A meteorological study of winds, temperatures and Pasquill stability categories was conducted in the coastal conditions at Jervis Bay. Three Pasquill stability categorisation schemes were compared. These indicated a predominance of neutral to slightly unstable conditions. During the daytime, north bay breezes and north-east sea breezes were most common together with on-shore south-east winds. Off-shore south-west winds prevailed during winter and were observed most frequently at night

  6. Comparison of multibody simulations and measurements of wind turbine gearboxes at Hansen’s 13 MW test facility

    OpenAIRE

    Marrant, Ben; Vanhollebeke, Frederik; Peeters, Joris

    2010-01-01

    Continuous up-scaling of wind turbine size into the multi-megawatt class, together with developments for off-shore installation are calling for new wind turbine configurations and technologies. High product reliability is a key factor in these developments, cascaded down to each component manufacturer in the supply chain. Increasing the reliability of wind turbine drive trains for wind turbines with ever increasing size requires dedicated simulation models which can provide more insight in th...

  7. PENERAPAN TEKNOLOGI TINGGI UNTUK PENGELOLAAN LIMBAH PADAT DI SINGAPURA

    OpenAIRE

    Wahyono, Sri

    2011-01-01

    The application of high technology (hitech) for solid waste management andtreatment in Singapore is one of examples of solving the municipal solid waste problem. Singapore with more than 4 million inhabitants produced 7676 ton wastes per day in 2001. Now, all the combustible solid wastes goes to the incinerator plant that can convert the heat into electricity. The ash from incinerator and the incombustible solid wastes are transported via waste harbour in Tuas to the Semakau off shore landfil...

  8. Piracy: The Best Business Model Available

    Science.gov (United States)

    2013-11-01

    occurring in West Africa.74 Oil workers on off-shore rigs have been periodically targeted for kid - napping. While the West African pirates have...118 Reports also link other human costs. Of those taken hostage, at least 60 percent were either used as human shields or physically abused by their...interpretation of verbal commands. Given that the crew may come from different countries, this can be a significant issue. Also, the multinational

  9. Offshore jurisdictions, controversial topic of the modern business world

    Directory of Open Access Journals (Sweden)

    Roxana-Daniela PĂUN

    2010-09-01

    Full Text Available This article aims to present synthetically the off-shore jurisdiction issues in the context of the globalisation of our lives and automatically of the business world facing new issues and challenges regarding the business in the international area, starting from defining elements and approaching some of the practical challenges offered by the widespread use of such offshore jurisdictions known as “tax havens”.

  10. Malampaya to boost flow of foreign investment

    International Nuclear Information System (INIS)

    Skrebowski, C.

    1995-01-01

    The petroleum industry in the Philippines has recently enjoyed a boost with the commissioning of a new modern refinery, and the development of sophisticated off-shore technology in the Malampaya/Camago oil and gas field. The foreign investment, which has made these initiatives possible, came about because of the countries new found political stability. It also reflects the rapid economic growth which has occurred and the accompanying increase in energy demand. (UK)

  11. How wind power landscapes change

    DEFF Research Database (Denmark)

    Möller, Bernd

    2006-01-01

    Following 25 years of continuous development, Danish wind energy landscapes are going to face changes. Ceased on-shore construction, unresolved re-powering and stalled regional planning characterize the situation overshadowed by off-shore development. One of the factors inhibiting development...... in general. However, the pattern of visibility will become askew, and the present homogenous distribution of visibility will disappear. This skewness, together with changing ownership and receding local involvement, could eventually lead to lower popular acceptance of wind power....

  12. Fabrication of plate for special applications by USIMINAS (Usinas Siderurgicas de Minas Gerais S/A)

    International Nuclear Information System (INIS)

    Andrade, S.L. de; Miyashita, T.; Hanan, I.

    1982-01-01

    Some aspects of the development of plate for applications in off-shore platforms, hydroelectric and nuclear industry, pressure vessels, heavy equipment and linepipe, have been discussed. Also dealt with are materials with special charateristics such as through-thickness ductility, tensile and impact properties after stress relief and ageing heat treatments, low temperature impact properties together with guaranteed ultrasonic quality that have been developed by USIMINAS in recent years. (Author) [pt

  13. The future of petroleum fuels

    International Nuclear Information System (INIS)

    Perrodon, A.

    1994-01-01

    Statistics concerning demand and supply for hydrocarbons in the near, medium and long terms are presented; in the long term, oil resources would come from discovery of new deposits, enhanced recovery and non conventional oils (deep off-shore, heavy oils, oil shales...). Production costs for proven oil reserves and resources and unconventional oils are also discussed together with the political, geographical and economical constraints on oil production. 10 figs., 10 refs

  14. Investigation of the generation and propagation of low frequency internal waves: A case study for the east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, A.D.; Babu, S.V.; Prasad, K.V.S.R.; Murty, T.V.R.; Sadhuram, Y.; Mahapatra, D.K.

    for Atmospheric Sciences, IIT Delhi b Department of Meteorology and Oceanography, Andhra University, Visakhapatnam c Regional Centre, National Institute of Oceanography, Visakhapatnam ABSTRACT SAR (Synthetic Aperture Radar) images in the northwest Bay... to facilitate a qualitative comparison with the available in-situ data analysis. Bhimili, with shallow off-shore bathymetry, ‘the shallow station’ and Vodalarevu, a relatively corresponding ‘deep station’ are shown in Figure 4. The location of the stations...

  15. Industrial policy: Where does innovation fit in?

    CSIR Research Space (South Africa)

    Levin, Saul

    2017-10-01

    Full Text Available to achieve economic growth. History has shown us that the most successful nations in terms of economic growth and development were those that supported and contributed to growing the industrial base of their economy. Even today those developed economies... point but that does not ensure rapid economic growth or economic development. History is also littered with those countries that became off-shore destinations for very cheap assembly only to find they lose their industrial base when conditions change...

  16. To future generations....

    Energy Technology Data Exchange (ETDEWEB)

    Drees, H.M. [Dutch Energy Corp., Rhenen (Netherlands)

    1997-12-31

    One of the world`s first 500 kW turbines was installed in the Netherlands in 1989. This forerunner of the current NedWind 500 kW range also represents the earliest predesign of the NedWind megawatt turbine. After the first turbines several design modifications followed, e.g. rotor diameter was increased and a tip brake was added. After that polyester blades were introduced and rotor diameter was further increased. The drive train was also redesigned. Improvements on the 500 kW turbine concept resulted in decreased cost and increased annual energy output. The 500 kW turbines serve in the first Dutch off-shore wind farm installed in 1994. This pilot project established proof that off-shore implementation is a promising option for the Dutch energy supply. Installation of megawatt turbines off-shore is currently being studied. Wind energy can substantially contribute to electricity supply. Maximum output in kilowatt-hours is the target.

  17. Lightning protection of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, T; Brask, M H [DEFU (Denmark); Jensen, F V; Raben, N [SEAS (Denmark); Saxov, J [Nordjyllandsvaerket (Denmark); Nielsen, L [Vestkraft (Denmark); Soerensen, P E [Risoe National Lab. (Denmark)

    1999-03-01

    Lightning damage to wind turbines is a serious problem for Danish power companies, who have experienced some cases with very costly lightning damage and a large number of cases with minor damage. The most costly cases include one catastrophic damage to an entire wind turbine, and several cases of destruction of blades, main bearings, generators and control systems. Over the years there have been several hundreds of cases with minor damage - typically damage and interruptions of the control and communication systems, or the power systems. The Danish power companies anticipate that the lightning threat will be even bigger for the large off-shore wind turbine installations that are currently being planned in Denmark. Furthermore, it is known from the off-shore wind turbines at Vindeby in Denmark that the costs of inspection and particularly repair work must be expected to be much higher off-shore as compared to wind turbines on land. These considerations was the background for a two year project concerned with investigation of lighting damages and with the formulation of a DEFU Recommendation for lightning protection of wind turbines, which was published in January 1999. The project was funded by the Danish power companies Elsam, Eltra, Elkraft and by DEFU. (au)

  18. Bats from Fazenda Intervales, Southeastern Brazil: species account and comparison between different sampling methods

    Directory of Open Access Journals (Sweden)

    Christine V. Portfors

    2000-06-01

    Full Text Available Assessing the composition of an area's bat fauna is typically accomplished by using captures or by monitoring echolocation calls with bat detectors. The two methods may not provide the same data regarding species composition. Mist nets and harp traps may be biased towards sampling low flying species, and bat detectors biased towards detecting high intensity echolocators. A comparison of the bat fauna of Fazenda Intervales, southeastern Brazil, as revealed by mist nets and harp trap captures, checking roosts and by monitoring echolocation calls of flying bats illustrates this point. A total of 17 species of bats was sampled. Fourteen bat species were captured and the echolocation calls of 12 species were recorded, three of them not revealed by mist nets or harp traps. The different sampling methods provided different pictures of the bat fauna. Phyllostomid bats dominated the catches in mist nets, but in the field their echolocation calls were never detected. No single sampling approach provided a complete assessment of the bat fauna in the study area. In general, bats producing low intensity echolocation calls, such as phyllostomids, are more easily assessed by netting, and bats producing high intensity echolocation calls are better surveyed by bat detectors. The results demonstrate that a combined and varied approach to sampling is required for a complete assessment of the bat fauna of an area.

  19. Donald Griffin Strove to give Animals their Due -Re-S-O-N-A-N-c-e--I ...

    Indian Academy of Sciences (India)

    Those of us who are fottunate to study animal behaviour cannot but marvel at the ... echolocation in bats and writing a widely accessible book Listening in the dark. ... [3] DR Griffin, Animal thinking, Harvard University Press, Cambridge, 1984.

  20. Vespertilionid bats control the width of their biosonar sound beam dynamically during prey pursuit

    DEFF Research Database (Denmark)

    Jakobsen, Lasse; Surlykke, Annemarie

    2010-01-01

    Animals using sound for communication emit directional signals, focusing most acoustic energy in one direction. Echolocating bats are listening for soft echoes from insects. Therefore, a directional biosonar sound beam greatly increases detection probability in the forward direction and decreases...

  1. Bats (Mammalia: Chiroptera) of the Eastern Mediterranean and Middle East. Part 10. Bat fauna of Iran

    Czech Academy of Sciences Publication Activity Database

    Benda, P.; Faizolahi, K.; Andreas, M.; Obuch, J.; Reiter, A.; Ševčík, M.; Uhrin, M.; Vallo, Peter; Ashrafi, S.

    2012-01-01

    Roč. 76, 3-4 (2012), s. 163-562 ISSN 1211-376X Institutional support: RVO:68081766 Keywords : distribution * ecology * echolocation * ectoparasites * Chiroptera * Iran * Middle East * Palaearctic Subject RIV: EG - Zoology

  2. Some new records of bats from Morocco (Chiroptera)

    Czech Academy of Sciences Publication Activity Database

    Benda, P.; Červený, J.; Konečný, Adam; Reiter, A.; Ševčík, M.; Uhrin, M.; Vallo, Peter

    2010-01-01

    Roč. 41, - (2010), s. 151-166 ISSN 0024-7774 Institutional research plan: CEZ:AV0Z60930519 Keywords : bats * North Africa * Western Sahara * distribution * echolocation * Maghreb Subject RIV: EG - Zoology

  3. The influence of feeding on the evolution of sensory signals: a comparative test of an evolutionary trade-off between masticatory and sensory functions of skulls in southern African horseshoe bats (Rhinolophidae).

    Science.gov (United States)

    Jacobs, D S; Bastian, A; Bam, L

    2014-12-01

    The skulls of animals have to perform many functions. Optimization for one function may mean another function is less optimized, resulting in evolutionary trade-offs. Here, we investigate whether a trade-off exists between the masticatory and sensory functions of animal skulls using echolocating bats as model species. Several species of rhinolophid bats deviate from the allometric relationship between body size and echolocation frequency. Such deviation may be the result of selection for increased bite force, resulting in a decrease in snout length which could in turn lead to higher echolocation frequencies. If so, there should be a positive relationship between bite force and echolocation frequency. We investigated this relationship in several species of southern African rhinolophids using phylogenetically informed analyses of the allometry of their bite force and echolocation frequency and of the three-dimensional shape of their skulls. As predicted, echolocation frequency was positively correlated with bite force, suggesting that its evolution is influenced by a trade-off between the masticatory and sensory functions of the skull. In support of this, variation in skull shape was explained by both echolocation frequency (80%) and bite force (20%). Furthermore, it appears that selection has acted on the nasal capsules, which have a frequency-specific impedance matching function during vocalization. There was a negative correlation between echolocation frequency and capsule volume across species. Optimization of the masticatory function of the skull may have been achieved through changes in the shape of the mandible and associated musculature, elements not considered in this study. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  4. Body lift, drag and power are relatively higher in large-eared than in small-eared bat species

    DEFF Research Database (Denmark)

    Håkansson, Jonas; Jakobsen, Lasse; Hedenström, Anders

    2017-01-01

    Bats navigate the dark using echolocation. Echolocation is enhanced by external ears, but external ears increase the projected frontal area and reduce the streamlining of the animal. External ears are thus expected to compromise flight efficiency, but research suggests that very large ears may mi....... The result of this trade-off would be the eco-morphological correlation in bat flight, with large-eared bats generally adopting slow-flight feeding strategies....

  5. The monterey bay broadband ocean bottom seismic observatory

    Directory of Open Access Journals (Sweden)

    R. Uhrhammer

    2006-06-01

    Full Text Available We report on the installation of a long-term buried ocean-floor broadband seismic station (MOBB in Monterey Bay, California (USA, 40km off-shore, at a water depth of 1000 m. The station was installed in April 2002 using a ship and ROV, in a collaborative effort between the Monterey Bay Aquarium Research Institute (MBARI and the Berkeley Seismological Laboratory (BSL. The station is located on the western side of the San Gregorio Fault, a major fault in the San Andreas plate boundary fault system. In addition to a 3-component CMG-1T seismometer package, the station comprises a current meter and Differential Pressure Gauge, both sampled at high-enough frequency (1 Hz to allow the study of relations between background noise on the seismometers and ocean waves and currents. The proximity of several land-based broadband seismic stations of the Berkeley Digital Seismic Network allows insightful comparisons of land/ocean background seismic noise at periods relevant to regional and teleseismic studies. The station is currently autonomous. Recording and battery packages are exchanged every 3 months during scheduled one day dives. Ultimately, this station will be linked to shore using continuous telemetry (cable and/or buoy and will contribute to the earthquake notification system in Northern California. We present examples of earthquake and noise data recorded during the first 6 months of operation of MOBB. Lessons learned from these and continued recordings will help understand the nature and character of background noise in regional off-shore environments and provide a reference for the installation of future off-shore temporary and permanent broadband seismic stations.

  6. Assessing Spatiotemporal Variability in NO2 and O3 Along the Korean Peninsula Using Remote Sensing and Ground-Based Observations

    Science.gov (United States)

    Li, C. Y. R.; Parker, O.; Tzortziou, M.

    2017-12-01

    Our research sought to use ground-based and satellite products to study the spatiotemporal variability of NO2 and O­3 in urban and coastal South Korea. Our data set was derived from direct-sun irradiance measurements of TCNO2 and TCO3 using Pandora spectrometers located at 8 ground sites and 1 boat-mounted sensor, as well as satellite observations from the Ozone Monitoring Instrument (OMI) on the Aura satellite. Our analysis focuses on the dates of the KORUSA campaign, which took place between May 18, 2016 through June 2, 2016, and provided our off-shore measurements. The Pandora instrument offered us continuous coverage of the local area, providing a detailed understanding of NO2 and O3 temporal variability. Ground stations allowed us to compare small-scale diurnal variability in urban and near-urban environments, while the Pandora mounted on the Onnuri research vessel permitted us to gain valuable insight into off-shore behavior of trace gases. By overlaying and comparing these measurements with TCO3/TCNO2 products from the Aura-OMI sensor, we were able to form a relatively complete picture of trace gas behavior above, and off-shore from, the Korean Peninsula. Our data was then subjected to statistical and GIS (Geographic Information System) analysis, quantifying and mapping (respectively) the spatial and temporal variability of total column amounts of NO2 and O3 along the Korean Peninsula. Results are shown for the eight sites where different Pandora instruments were used. There was a notable difference in TCNO2 variability which correlates with population and land use.

  7. The occurrence of triglycerides in Namibian Shelf diatomaceous ooze

    Science.gov (United States)

    Boon, Jaap J.; Irene, W.; Rijpstra, C.; de Leeuw, J. W.; Burlingame, A. L.

    1980-01-01

    The triglyceride fraction, isolated from extractable lipids of a diatomaceous ooze off shore Walvis Bay (S.W. Africa) by TLC methods, was analyzed by direct probe low and high resolution mass spectrometry. The mass spectral data reveal the fatty acid moieties and their relative distribution in the triglycerides identified. The C 12, C 14, C 15 and C 16 are the major composing fatty acid moieties. The triglycerides are thought to be present in protective structures such as diatom spores, which were found to be present by scanning electron microscopy.

  8. Cooperative control system of the floating cranes for the dual lifting

    OpenAIRE

    Mihee Nam; Jinbeom Kim; Jaechang Lee; Daekyung Kim; Donghyuk Lee; Jangmyung Lee

    2018-01-01

    This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes ...

  9. Modular Multi-level converter based HVDC System for Grid Connection of Offshore Wind Power Plant

    DEFF Research Database (Denmark)

    Gnanarathna, U.N.; Chaudhary, Sanjay Kumar; Gole, A.M.

    2010-01-01

    This paper explores the application of modular multi-level converters (MMC) as a means for harnessing the power from off-shore wind power plants. The MMC consists of a large number of simple voltage sourced converter (VSC) submodules that can be easily assembled into a converter for high......-voltage and high power. The paper shows that the MMC converter has a fast response and low harmonic content in comparison with a two-level VSC option. The paper discusses the modeling approach used, including a solution to the modeling challenge imposed by the very large number of switching devices in the MMC....

  10. Overview of DFIG-based Wind Power System Resonances under Weak Networks

    DEFF Research Database (Denmark)

    Song, Yipeng; Blaabjerg, Frede

    2017-01-01

    The wind power generation techniques are continuing to develop and increasing numbers of Doubly Fed Induction Generator (DFIG)-based wind power systems are connecting to the on-shore and off-shore grids, local standalone weak networks, and also micro grid applications. The impedances of the weak...... scale of DFIG system with different parameters; 3) L or LCL filter adopted in the Grid Side Converter (GSC); 4) rotor speed; 5) current closed-loop controller parameters and 6) digital control delay will be discussed in this paper. On the basis of the analysis, active damping strategies for HFR using...

  11. Experimental Study of Wave Forces on Vertical Circular Cylinders in Long and Short Crested Sea

    DEFF Research Database (Denmark)

    Høgedal, Michael

    on the safe side, as the directional spreading of the wave field Ieads to reduced horizontal velocities and acceleration; in the fluid and hence a reduction of the resultant and in-line wave forces on the structure. The directional spreading of the horizontal velocity field generally causes an increase...... with miniature pressure transducers. The experiments were carried out in the 3-D wave tank in the Hydraulics & Coastal Engineering Laboratory at Aalborg University and in the off-shore basin at the Danish Hydraulic Institute....

  12. International Conference on Computational Engineering Science

    CERN Document Server

    Yagawa, G

    1988-01-01

    The aim of this Conference was to become a forum for discussion of both academic and industrial research in those areas of computational engineering science and mechanics which involve and enrich the rational application of computers, numerical methods, and mechanics, in modern technology. The papers presented at this Conference cover the following topics: Solid and Structural Mechanics, Constitutive Modelling, Inelastic and Finite Deformation Response, Transient Analysis, Structural Control and Optimization, Fracture Mechanics and Structural Integrity, Computational Fluid Dynamics, Compressible and Incompressible Flow, Aerodynamics, Transport Phenomena, Heat Transfer and Solidification, Electromagnetic Field, Related Soil Mechanics and MHD, Modern Variational Methods, Biomechanics, and Off-Shore-Structural Mechanics.

  13. Selected Problems of Sensitivity and Reliability of a Jack-Up Platform

    Directory of Open Access Journals (Sweden)

    Rozmarynowski Bogdan

    2018-03-01

    Full Text Available The paper deals with sensitivity and reliability applications to numerical studies of an off-shore platform model. Structural parameters and sea conditions are referred to the Baltic jack-up drilling platform. The sudy aims at the influence of particular basic variables on static and dynamic response as well as the probability of failure due to water waves and wind loads. The paper presents the sensitivity approach to a generalized eigenvalue problem and evaluation of the performace functions. The first order time-invariant problems of structural reliability analysis are under concern.

  14. Nitrogen cycling in the suboxic waters of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Devol, A.H.; Naqvi, S.W.A.; Codispoti, L.A.

    primary production in a section extending about 1000 km off shore from the Arabian coast (1.5 g C m-* d-'; [6]). The Northeast Monsoon (December- February) is characterized by moderate winds From the Himalayas that send cool, dry air over the region... the surface oxygen concentration is high, but by time it reaches the southern border of the ODZ (- 14"N) it loses almost all of its dissolved oxygen (Fig 1; 1771). Thus the combination of high oxygen demand and low oxygen source waters results in the strong...

  15. The safety culture of the nuclear plants of Sydkraft. Appendices 5-7

    International Nuclear Information System (INIS)

    Edmondson, B.; Firing, J.A.; Nordland, O.S.; Ottne, E.

    1994-01-01

    This separate volume of appendices contains three contributions: ''Safety in Nuclear Electric'' by Bryan Edmondson, which reviews the legislation for nuclear safety in Britain, reproduces the Health and Policy Statement by Nuclear Electric, and describes the management of health and safety in the company. ''Safety in Norwegian off-shore industry'' by Joergen A. Firing, describing the safety practices of the Statoil Group and reproducing the relevant Norwegian law. ''The safety management in SAS Airline. The safety and quality in airline industries'' by O.S. Nordland and E. Ottne describing safety organization, internal control systems, and education and training in SAS

  16. Surf Utopia

    OpenAIRE

    Goffin, Jeremy

    2016-01-01

    With swell data at our finger tips, the what where when and how drives the daily search bars. Being lucky enough to catch the wind and waves together are what dreams are made of. Whilst visually deconstructing the perfect conditions I've focused the elements down to the main details. Size, Swell Period, Temperature and Wind Speed manages the core information whilst leaving out the politics of the on or off shore debates. Either in board shorts or in a thermal wet suit, big gnarly...

  17. Ensuring on-time quality data management deliverables from global clinical data management teams

    Directory of Open Access Journals (Sweden)

    Zia Haque

    2010-01-01

    Full Text Available The growing emphasis on off-site and off-shore clinical data management activities mandates a paramount need for adequate solutions geared toward on-time, quality deliverables. The author has been leading large teams that have been involved in successful global clinical data management endeavors. While each study scenario is unique and has to be approached as such, there are several elements in defining strategy and team structure in global clinical data management that can be applied universally. In this article, key roles, practices, and high-level procedures are laid out as a road map to ensure success with the model.

  18. Ice Forces on Offshore Wind Power Plants. Descriptions of mechanisms and recommendations for dimensioning; Islaster paa vindkraftverk till havs. Beskrivning av mekanismer och rekommendationer foer dimensionering

    Energy Technology Data Exchange (ETDEWEB)

    Bergdahl, Lars [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept of Water Environment Transport

    2002-02-01

    Mechanisms for ice-loads on off-shore wind power plants are described, The ice-loads are due to thermal expansion, water level variations, drifting ice and ice-reefing. Ice accretion is briefly treated. Ice instance, ice thickness, ice retention time, water level variations and stream velocities in Swedish waters are compiled. The main text deals with recommendations for dimensioning wind power plants at sea. In the appendices, a thorough review of the physical and mechanical properties of ice is presented.

  19. Water resources and water pollution studies

    International Nuclear Information System (INIS)

    Airey, P.

    2001-01-01

    Nuclear techniques are widely used in the investigation of the dynamics of the water cycle. This paper focusses on their contributions to the development of strategies for the sustainability of environmental resources. Emphasis has been placed on the role of environmental isotopes and radiotracers in evaluating models of complex environmental systems. Specific reference is made to 1) the construction of a marine radioactivity database for Asia and the Pacific, 2) the sustainability of groundwater in regions challenged by climate change, and 3) the applications of radiotracers to off-shore transport of sediments and contaminants

  20. The new role of Brazil in energy geopolitics; La nouvelle place du Bresil dans la geopolitique de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, I. [Centro de Estudios Internacionales - El Colegio de Mexico (Brazil)

    2009-11-15

    Thanks to its efficient petroleum framework, Brazil has just found some very large deep off-shore fields (pre-halite layers), which, if confirmed, will allow the country to become a major international oil producer. There will be significant repercussions on Brazil. On the one hand, the prospect of high economic rents encourages it to assign its hydrocarbon industry a more social and national calling; on the other hand, this huge potential offers Brazil a new geopolitical dimension. This article examines both these avenues. (author)

  1. Working group 5: Safety

    International Nuclear Information System (INIS)

    Vinck, W.

    1976-01-01

    The technical aspects of safety for the LWR nuclear power plants, and a reprocessing plant are considered. The origin, the type and the extent of the risks for the civil populations are presented for normal working as well as accidental conditions. A general estimate of comparative risks is given for the nuclear industry with respect to other activities. The legal Belgian aspects and their applications, the kind and the quality of the technical testings, the back-fitting of plants are analysed. Considerations are given on the probabilistic analysis, the safety, and the off-shore power plants. (A.F.)

  2. Integrated Wind Power Planning Tool

    DEFF Research Database (Denmark)

    Rosgaard, M. H.; Hahmann, Andrea N.; Nielsen, T. S.

    This poster describes the status as of April 2012 of the Public Service Obligation (PSO) funded project PSO 10464 \\Integrated Wind Power Planning Tool". The project goal is to integrate a meso scale numerical weather prediction (NWP) model with a statistical tool in order to better predict short...... term power variation from off shore wind farms, as well as to conduct forecast error assessment studies in preparation for later implementation of such a feature in an existing simulation model. The addition of a forecast error estimation feature will further increase the value of this tool, as it...

  3. Power transmission study for a wave energy scheme based on Lancaster Flexible Bag devices. Supervisory and telecontrol system

    Energy Technology Data Exchange (ETDEWEB)

    1981-11-01

    Various options are considered for power data transmission associated with the power collection and transmission system of a postulated wave energy conversion scheme off the Outer Hebrides. For data transmission between the off-shore and on-shore power collector stations a Power Line Carrier (PLC) system is judged to be most suitable. In the case of data transmission between power collector stations and the main control centre, a microwave/radio link is proposed as the amount of data does not lend itself to a PLC system. Cost estimates, in the main for equipment supply only, are given.

  4. The new role of Brazil in energy geopolitics

    International Nuclear Information System (INIS)

    Rousseau, I.

    2009-01-01

    Thanks to its efficient petroleum framework, Brazil has just found some very large deep off-shore fields (pre-halite layers), which, if confirmed, will allow the country to become a major international oil producer. There will be significant repercussions on Brazil. On the one hand, the prospect of high economic rents encourages it to assign its hydrocarbon industry a more social and national calling; on the other hand, this huge potential offers Brazil a new geopolitical dimension. This article examines both these avenues. (author)

  5. Towards a Methodology for Managing Competencies in Virtual Teams - A Systemic Approach

    Science.gov (United States)

    Schumacher, Marinita; Stal-Le Cardinal, Julie; Bocquet, Jean-Claude

    Virtual instruments and tools are future trends in Engineering which are a response to the growing complexity of engineering tasks, the facility of communication and strong collaborations on the international market. Outsourcing, off-shoring, and the globalization of organisations’ activities have resulted in the formation of virtual product development teams. Individuals who are working in virtual teams must be equipped with diversified competencies that provide a basis for virtual team building. Thanks to the systemic approach of the functional analysis our paper responds to the need of a methodology of competence management to build virtual teams that are active in virtual design projects in the area of New Product Development (NPD).

  6. Competition and efficiency: application to tax haven, profit shifting and platform competition

    OpenAIRE

    Oh, David Kyungtaek

    2017-01-01

    The first chapter considers the tax information exchange agreement as a way to draw Pareto improvement between off-shore tax havens and non-haven countries. Individuals who reside in a non-haven country choose the volume of tax evasion to maximize the expected payoff which depends on the tax rate and the probability of being detected. A tax haven might be reluctant to sign a TIEA since establishing a TIEA increases the probability of detection thus decreasing the volume of individuals' tax ev...

  7. Design of the ANTARES LCM-DAQ board test bench using a FPGA-based system-on-chip approach

    Energy Technology Data Exchange (ETDEWEB)

    Anvar, S. [CEA Saclay, DAPNIA/SEDI, 91191 Gif-sur-Yvette Cedex (France); Kestener, P. [CEA Saclay, DAPNIA/SEDI, 91191 Gif-sur-Yvette Cedex (France)]. E-mail: pierre.kestener@cea.fr; Le Provost, H. [CEA Saclay, DAPNIA/SEDI, 91191 Gif-sur-Yvette Cedex (France)

    2006-11-15

    The System-on-Chip (SoC) approach consists in using state-of-the-art FPGA devices with embedded RISC processor cores, high-speed differential LVDS links and ready-to-use multi-gigabit transceivers allowing development of compact systems with substantial number of IO channels. Required performances are obtained through a subtle separation of tasks between closely cooperating programmable hardware logic and user-friendly software environment. We report about our experience in using the SoC approach for designing the production test bench of the off-shore readout system for the ANTARES neutrino experiment.

  8. Assessment of Renewable Sources for the Energy Consumption in Malta in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Vincenzo Franzitta

    2016-12-01

    Full Text Available The main purpose of this paper is to analyze the energy production in the Maltese islands, focusing on the employment of renewable energies in order to increase their energy independence. The main renewable source here proposed is wave energy: thanks to a strategic position, Malta will be able to produce electrical energy using an innovative type of Wave Energy Converter (WEC based on the prototype of a linear generator realized by University of Palermo. The use of this new technology will be able to cut down the electrical energy production from traditional power plants and, consequently, the greenhouse gas emissions (GHG. Wave energy source and off-shore photovoltaic (PV technology are here proposed. Particularly, the installation of 12 wave farms, for a total installed capacity of 86 MW, will generate about 9.5% of Malta’s energy requirement in 2025, while the installation of 9.6 MW of off-shore PV will generate about 0.73%.

  9. Strategies for obtaining obsidian in pre-European contact era New Zealand.

    Science.gov (United States)

    McCoy, Mark D; Carpenter, Jonathan

    2014-01-01

    Archaeological evidence of people's choices regarding how they supply themselves with obsidian through direct access and different types of exchanges gives us insight in to mobility, social networks, and property rights in the distant past. Here we use collections of obsidian artefacts that date to a period of endemic warfare among Maori during New Zealand's Late Period (1500-1769 A.D.) to determine what strategies people engaged in to obtain obsidian, namely (1) collecting raw material directly from a natural source, (2) informal trade and exchange, and (3) formal trade and exchange. These deposits represent a good cross-section of Late Period archaeology, including primary working of raw material at a natural source (Helena Bay), undefended sites where people discarded rubbish and worked obsidian (Bream Head), and a heavily fortified site (Mt. Wellington). We find that most of the obsidian described here was likely obtained directly from natural sources, especially those located on off-shore islands within about 60-70 km of sites. A smaller amount comes from blocks of material transported from an off-shore island a greater distance away, called Mayor Island, in a formal trade and exchange network. This study demonstrates the value of conducting tandem lithic technology and geochemical sourcing studies to understand how people create and maintain social networks during periods of warfare.

  10. Strategies for obtaining obsidian in pre-European contact era New Zealand.

    Directory of Open Access Journals (Sweden)

    Mark D McCoy

    Full Text Available Archaeological evidence of people's choices regarding how they supply themselves with obsidian through direct access and different types of exchanges gives us insight in to mobility, social networks, and property rights in the distant past. Here we use collections of obsidian artefacts that date to a period of endemic warfare among Maori during New Zealand's Late Period (1500-1769 A.D. to determine what strategies people engaged in to obtain obsidian, namely (1 collecting raw material directly from a natural source, (2 informal trade and exchange, and (3 formal trade and exchange. These deposits represent a good cross-section of Late Period archaeology, including primary working of raw material at a natural source (Helena Bay, undefended sites where people discarded rubbish and worked obsidian (Bream Head, and a heavily fortified site (Mt. Wellington. We find that most of the obsidian described here was likely obtained directly from natural sources, especially those located on off-shore islands within about 60-70 km of sites. A smaller amount comes from blocks of material transported from an off-shore island a greater distance away, called Mayor Island, in a formal trade and exchange network. This study demonstrates the value of conducting tandem lithic technology and geochemical sourcing studies to understand how people create and maintain social networks during periods of warfare.

  11. Ovis: A framework for visual analysis of ocean forecast ensembles

    KAUST Repository

    Hollt, Thomas; Magdy, Ahmed; Zhan, Peng; Chen, Guoning; Gopalakrishnan, Ganesh; Hoteit, Ibrahim; Hansen, Charles D.; Hadwiger, Markus

    2014-01-01

    We present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations of the sea surface height that is used in ocean forecasting. The position of eddies can be derived directly from the sea surface height and our visualization approach enables their interactive exploration and analysis.The behavior of eddies is important in different application settings of which we present two in this paper. First, we show an application for interactive planning of placement as well as operation of off-shore structures using real-world ensemble simulation data of the Gulf of Mexico. Off-shore structures, such as those used for oil exploration, are vulnerable to hazards caused by eddies, and the oil and gas industry relies on ocean forecasts for efficient operations. We enable analysis of the spatial domain, as well as the temporal evolution, for planning the placement and operation of structures.Eddies are also important for marine life. They transport water over large distances and with it also heat and other physical properties as well as biological organisms. In the second application we present the usefulness of our tool, which could be used for planning the paths of autonomous underwater vehicles, so called gliders, for marine scientists to study simulation data of the largely unexplored Red Sea. © 1995-2012 IEEE.

  12. Experimental researches of marine wave parameters in the Black Sea Basin

    Science.gov (United States)

    Panaitescu, Fanel-Viorel; Panaitescu, Mariana; Anton, Iulia-Alina

    2016-12-01

    In this paper are presented the process of measuring parameters of marine waves with performed devices which permit to obtain the values of the speed and current division marine wave amplitude and direction of the wave at each measurement, the number of measurements, date, hour, minute and second of measurement. This monitoring, which comprises the period of one year including, reveals an amplitude an annual average of the wave of hmed=1.53 m, obtained by taking maximum envelope appeared in a measurement range of 120 seconds. The value is unexpectedly high, taking into account of the fact that on the coastline it was found of: hmed =0.467 m at Constanta Station and hmed =0.23 m at Mangalia Station. These results reveal that there is a energy potential that exceeds expectations, much larger in the area of off shore, that is to say, in more than 12 Mm off shore, in front of the coastal zone. These measurements were applied with two devices-one device for measuring hidrostatic amplitude test and other device, ADV(Advanced Doppler velocymmeter).

  13. Towards the development of mechanistically based design rules for corrosion fatigue in ductile steels

    International Nuclear Information System (INIS)

    Johnson, R.; McMinn, A.; Tomkins, B.

    1980-08-01

    Design curves for nuclear pressure vessels and off-shore structures are based on air endurance curves that have had a safety factor applied to account for effects such as corrosive environments, frequency and mean stress. These are supported by a limited number of endurance tests on actual pressure vessels, and on welded joints under service conditions. These data-based rules are limited in their ability to cope with environmental effects and as the time dependencies of fatigue and corrosion processes are so different, no sound basis exists for the extrapolation of data to long component lifetimes. The crack-growth behaviour of materials used in nuclear pressure vessels and off-shore structures is examined with a view to determining how it may be used to re-assess the design curves. Even simple integration of crack-growth laws can be seen to be within reasonable agreement with present design curves; with improved methods of stress analysis, etc. this approach could potentially improve these curves. Mechanistic studies are also seen to offer a means of examining and assessing time-dependent process interactions and so, potentially, to form the basis of new guidelines. Finally the areas where further work would be needed to substantiate any changes in design curves are indicated. (author)

  14. Experimental study of a model and parameters calculating annual mean atmospheric dispersion factor for a nuclear power plant to be build in coastal site

    International Nuclear Information System (INIS)

    Hu Erbang; Chen Jiayi; Zhang Maoshuan; Gao Zhanrong; Yao Rentai; Jia Peirong; Qiao Qingdang

    1999-01-01

    The author tries to develop a new model calculating annual mean atmospheric dispersion factor for a nuclear power plant to be build in coastal site based on field experiments. This model considers not only the difference between shore ward and off-shore but also the comprehensive effect of following factors: mixed layer and thermal internal boundary layer, mixing release and variation of diffusion parameters due to the distance from coast and so on. The various parameters needed in the model are obtained from the field atmospheric experiments done on the NPP site during 1995∼1996. There dimension joint frequency is got from wind and temperature measurements at 4 heights of a tower of 100 m; diffusion parameters shore ward and off-shore from turbulent measurement and wind tunnel simulation test; the parameters relative to sea and land breeze and thermal internal boundary layer are obtained from tests with low altitude radiosonde and lost balloon at 3 sites during two periods of Summer and Winter. Finally a comparison of the results given by this model and commonly used model provided by relative guides is done. The comparison shows that about 1 times under estimation is found for the maximum of annual mean atmospheric dispersion factor in common model because the effect from thermal internal boundary layer and other factors are neglected

  15. Occurrence and Biological Fate of Persistent Organic Contaminants in Yellow Sea Fish

    Directory of Open Access Journals (Sweden)

    Narayanan Kannan

    2010-01-01

    Full Text Available Persistent Organic Pollutants (POPs, namely, Polychlorinated biphenyls (PCBs, DDTs, HCHs, HCB, aldrin, endrin, dieldrin, endosulfan, heptachlors, mirex and chlordane compounds were investigated in muscle and liver tissues of Yellow Sea croakers (Collichthys niveatus and Pseudosciaena crocea from 16 stations on the off shore waters of South Korea within the Yellow Sea Large Marine Ecosystem (YSLME. The sum concentration (minimum-maximum - ng/g lipid wt. was: PCBs: non-detectable to 21; Pesticides non-detectable to 63. Among the 26 individual pesticide compounds measured in fishes, except 1,2,4,5-tetrachlorobenzene (TCBZ, all the other compounds were determined in almost in all samples. The levels in Yellow Sea croakers were similar to levels reported in the Baltic fish. The differential ratios of isomers/congeners in biota in comparison to the original commercial mixtures suggest possible metabolism by cytochrome P450 isozymes. The induction of such drug metabolizing enzymes suggests an ecotoxicological stress. Principle Component Analysis identifies ‘hot spots’ within the sampled area including the Korean off shore sewage dumpsite.

  16. Ovis: A Framework for Visual Analysis of Ocean Forecast Ensembles.

    Science.gov (United States)

    Höllt, Thomas; Magdy, Ahmed; Zhan, Peng; Chen, Guoning; Gopalakrishnan, Ganesh; Hoteit, Ibrahim; Hansen, Charles D; Hadwiger, Markus

    2014-08-01

    We present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations of the sea surface height that is used in ocean forecasting. The position of eddies can be derived directly from the sea surface height and our visualization approach enables their interactive exploration and analysis.The behavior of eddies is important in different application settings of which we present two in this paper. First, we show an application for interactive planning of placement as well as operation of off-shore structures using real-world ensemble simulation data of the Gulf of Mexico. Off-shore structures, such as those used for oil exploration, are vulnerable to hazards caused by eddies, and the oil and gas industry relies on ocean forecasts for efficient operations. We enable analysis of the spatial domain, as well as the temporal evolution, for planning the placement and operation of structures.Eddies are also important for marine life. They transport water over large distances and with it also heat and other physical properties as well as biological organisms. In the second application we present the usefulness of our tool, which could be used for planning the paths of autonomous underwater vehicles, so called gliders, for marine scientists to study simulation data of the largely unexplored Red Sea.

  17. Ovis: A framework for visual analysis of ocean forecast ensembles

    KAUST Repository

    Hollt, Thomas

    2014-08-01

    We present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations of the sea surface height that is used in ocean forecasting. The position of eddies can be derived directly from the sea surface height and our visualization approach enables their interactive exploration and analysis.The behavior of eddies is important in different application settings of which we present two in this paper. First, we show an application for interactive planning of placement as well as operation of off-shore structures using real-world ensemble simulation data of the Gulf of Mexico. Off-shore structures, such as those used for oil exploration, are vulnerable to hazards caused by eddies, and the oil and gas industry relies on ocean forecasts for efficient operations. We enable analysis of the spatial domain, as well as the temporal evolution, for planning the placement and operation of structures.Eddies are also important for marine life. They transport water over large distances and with it also heat and other physical properties as well as biological organisms. In the second application we present the usefulness of our tool, which could be used for planning the paths of autonomous underwater vehicles, so called gliders, for marine scientists to study simulation data of the largely unexplored Red Sea. © 1995-2012 IEEE.

  18. One tone, two ears, three dimensions: a robotic investigation of pinnae movements used by rhinolophid and hipposiderid bats.

    Science.gov (United States)

    Walker, V A; Peremans, H; Hallam, J C

    1998-07-01

    Bats, which echolocate using broadband calls, are believed to employ the passive acoustic filtering properties of the head and pinnae to provide spectral cues which encode 3-D target angle. Microchiropteran species whose calls consist of a single, constant frequency harmonic (i.e., some species in the families Rhinolophidae and Hipposideridae) may create additional acoustic localization cues via vigorous pinna movements. In this work, two types of echolocation cues generated by moving a pair of receivers aboard a model sensor head are investigated. In the first case, it is supposed that a common 3-D echolocation principle employed by all bats is the creation of alternative viewing perspectives, and that constant frequency (CF) echolocators use pinna movement rather than morphology to alter the acoustic axes of their perceptual systems. Alternatively, it is possible rhinolophids and hipposiderids move their ears to create dynamic cues--in the form of frequency and amplitude modulations--which vary systematically with target elevation. Here the use of binaural and monaural timing cues derived from amplitude modulated echo envelopes are investigated. In this case, pinna mobility provides an echolocator with a mechanism for creating dramatic temporal cues for directional sensing which, unlike interaural timing differences, do not degrade with head size.

  19. Age-dependent gene expression in the inner ear of big brown bats (Eptesicus fuscus.

    Directory of Open Access Journals (Sweden)

    Beatrice Mao

    Full Text Available For echolocating bats, hearing is essential for survival. Specializations for detecting and processing high frequency sounds are apparent throughout their auditory systems. Recent studies on echolocating mammals have reported evidence of parallel evolution in some hearing-related genes in which distantly related groups of echolocating animals (bats and toothed whales, cluster together in gene trees due to apparent amino acid convergence. However, molecular adaptations can occur not only in coding sequences, but also in the regulation of gene expression. The aim of this study was to examine the expression of hearing-related genes in the inner ear of developing big brown bats, Eptesicus fuscus, during the period in which echolocation vocalizations increase dramatically in frequency. We found that seven genes were significantly upregulated in juveniles relative to adults, and that the expression of four genes through development correlated with estimated age. Compared to available data for mice, it appears that expression of some hearing genes is extended in juvenile bats. These results are consistent with a prolonged growth period required to develop larger cochlea relative to body size, a later maturation of high frequency hearing, and a greater dependence on high frequency hearing in echolocating bats.

  20. Wireless recording of the calls of Rousettus aegyptiacus and their reproduction using electrostatic transducers

    International Nuclear Information System (INIS)

    Whiteley, S M; Hayward, G; Pierce, S G; Waters, D A; Farr, I

    2010-01-01

    Bats are capable of imaging their surroundings in great detail using echolocation. To apply similar methods to human engineering systems requires the capability to measure and recreate the signals used, and to understand the processing applied to returning echoes. In this work, the emitted and reflected echolocation signals of Rousettus aegyptiacus are recorded while the bat is in flight, using a wireless sensor mounted on the bat. The sensor is designed to replicate the acoustic gain control which bats are known to use, applying a gain to returning echoes that is dependent on the incurred time delay. Employing this technique allows emitted and reflected echolocation calls, which have a wide dynamic range, to be recorded. The recorded echoes demonstrate the complexity of environment reconstruction using echolocation. The sensor is also used to make accurate recordings of the emitted calls, and these calls are recreated in the laboratory using custom-built wideband electrostatic transducers, allied with a spectral equalization technique. This technique is further demonstrated by recreating multi-harmonic bioinspired FM chirps. The ability to record and accurately synthesize echolocation calls enables the exploitation of biological signals in human engineering systems for sonar, materials characterization and imaging.

  1. Object representation in the bottlenose dolphin (Tursiops truncatus): integration of visual and echoic information.

    Science.gov (United States)

    Harley, H E; Roitblat, H L; Nachtigall, P E

    1996-04-01

    A dolphin performed a 3-alternative matching-to-sample task in different modality conditions (visual/echoic, both vision and echolocation: visual, vision only; echoic, echolocation only). In Experiment 1, training occurred in the dual-modality (visual/echoic) condition. Choice accuracy in tests of all conditions was above chance without further training. In Experiment 2, unfamiliar objects with complementary similarity relations in vision and echolocation were presented in single-modality conditions until accuracy was about 70%. When tested in the visual/echoic condition, accuracy immediately rose (95%), suggesting integration across modalities. In Experiment 3, conditions varied between presentation of sample and alternatives. The dolphin successfully matched familiar objects in the cross-modal conditions. These data suggest that the dolphin has an object-based representational system.

  2. Visual Workflows for Oil and Gas Exploration

    KAUST Repository

    Hollt, Thomas

    2013-04-14

    The most important resources to fulfill today’s energy demands are fossil fuels, such as oil and natural gas. When exploiting hydrocarbon reservoirs, a detailed and credible model of the subsurface structures to plan the path of the borehole, is crucial in order to minimize economic and ecological risks. Before that, the placement, as well as the operations of oil rigs need to be planned carefully, as off-shore oil exploration is vulnerable to hazards caused by strong currents. The oil and gas industry therefore relies on accurate ocean forecasting systems for planning their operations. This thesis presents visual workflows for creating subsurface models as well as planning the placement and operations of off-shore structures. Creating a credible subsurface model poses two major challenges: First, the structures in highly ambiguous seismic data are interpreted in the time domain. Second, a velocity model has to be built from this interpretation to match the model to depth measurements from wells. If it is not possible to obtain a match at all positions, the interpretation has to be updated, going back to the first step. This results in a lengthy back and forth between the different steps, or in an unphysical velocity model in many cases. We present a novel, integrated approach to interactively creating subsurface models from reflection seismics, by integrating the interpretation of the seismic data using an interactive horizon extraction technique based on piecewise global optimization with velocity modeling. Computing and visualizing the effects of changes to the interpretation and velocity model on the depth-converted model, on the fly enables an integrated feedback loop that enables a completely new connection of the seismic data in time domain, and well data in depth domain. For planning the operations of off-shore structures we present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations used in ocean

  3. Economic benefits of subsea flexible flowlines

    International Nuclear Information System (INIS)

    Hill, R.T.; Measamer, J.C.

    1993-01-01

    The development of marginal off-shore hydrocarbon deposits has resulted in production of increasingly corrosive fluids, thus furthering the need for pipelines capable of operating at elevated temperatures in the presence of high concentrations of H 2 S and CO 2 gases. Conventional pipelines require the use of stainless steels or other corrosion resistant alloys which drives up the cost of materials and fabrication/installation of the system. The use of flexible pipe is assuming an important role in these applications where the selection of compatible metallic and non-metallic components have resulted in cost effective alternatives. As development of marginal and aggressive hydrocarbon reservoirs increases operators are faced with providing systems which minimize the cost of field production. This paper describes the results of economic analyses of actual field developments in order to provide a methodology for selection of an appropriate pipeline technology to minimize life cycle costs of the flowline system

  4. Model Testing of the Wave Energy Converter Seawave Slot-Cone Generator

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter

    This report presents the results of a preliminary experimental study of the wave energy convert (WEC) Seawave Slot-Cone Generator (SSG). SSG is a WEC utilizing wave overtopping in multiple reservoirs. In the present SSG setup three reservoirs has been used. Model tests have been performed using...... a scale model (length scale 1:15) of a SSG device to be installed on the west coast of the island Kvitsøy near Stavanger, Norway. The tests were carried out at Dept. of Civil Engineering, Aalborg University (AAU) in the 3D deep water wave tank. The model has been subjected to regular and irregular waves...... corresponding to typical conditions off shore from the intended installation site. The overtopping rates for the individual reservoirs have been measured and the potential energy in the overtopping water has been calculated....

  5. Visual Workflows for Oil and Gas Exploration

    KAUST Repository

    Hollt, Thomas

    2013-01-01

    For planning the operations of off-shore structures we present a novel integrated visualization system that enables interactive visual analysis of ensemble simulations used in ocean forecasting, i.e, simulations of sea surface elevation. Changes in sea surface elevation are a good indicator for the movement of loop current eddies. Our visualization approach enables their interactive exploration and analysis. We enable analysis of the spatial domain, for planning the placement of structures, as well as detailed exploration of the temporal evolution at any chosen position, for the prediction of critical ocean states that require the shutdown of rig operations. We illustrate this using a real-world simulation of the Gulf of Mexico.

  6. Tribological study in roll forming of lean duplex stainless steel sheets

    DEFF Research Database (Denmark)

    Nielsen, Peter Søe; Nielsen, Morten Strogaard; Bay, Niels

    2012-01-01

    . Production tests show that galling can be a problem but pick-up formation on the tools seems to reach a consistent level. Improvements to tool surfaces and lubricant quality are proposed with a view to optimizing the tribo-system in order to increase the produced length before galling initiates and tool...... are relatively low and surface expansion is more or less non-existent, long roll forming production runs imply large sliding/contact lengths due to relative movement between steel strip and rolls. This requires an efficient tribological system to prevent pick-up formation on the forming tools. The present work...... focus on tribological issues are galling and pick-up formation as well as tool life in roll forming of stainless duplex steel sheets. The roll forming process is exemplified by production of an s-shaped profile used in interlock carcass production for flexible pipes used in off-shore oil extraction...

  7. Public hearing or 'hearing public'? an evaluation of the participation of local stakeholders in environmental impact assessment of Ghana's Jubilee oil fields.

    Science.gov (United States)

    Bawole, Justice Nyigmah

    2013-08-01

    This article investigates the involvement of local stakeholders in the environmental impact assessment (EIA) processes of Ghana's first off-shore oil fields (the Jubilee fields). Adopting key informants interviews and documentary reviews, the article argues that the public hearings and the other stakeholder engagement processes were cosmetic and rhetoric with the view to meeting legal requirements rather than a purposeful interest in eliciting inputs from local stakeholders. It further argues that the operators appear to lack the social legitimacy and social license that will make them acceptable in the project communities. A rigorous community engagement along with a commitment to actively involving local stakeholders in the corporate social responsibility (CSR) programmes of the partners may enhance the image of the partners and improve their social legitimacy. Local government agencies should be capacitated to actively engage project organisers; and government must mitigate the impact of the oil projects through well-structured social support programmes.

  8. Working group 4b: Regional aspects. Siting in Walloon region and offshore

    International Nuclear Information System (INIS)

    Wilmes, Ph.; Fincoeur, P.; Slegers, G.

    1976-01-01

    Four nuclear power plant solutions in view of siting have been considered. a) Saturation of the existing sites. The only site considered is Tihange where a 870 MWe power plant is operated and a 930 MWe is under construction. b) Creation of new sites only for the production of electrical power and/or thermal energy. There are two possibilities: the creation of a new site for big power stations on the Meuse river and the spreading of power plants of two kinds: supply of electricity only and double purpose production: vapor/electricity or heat/electricity. c) Creation of complete sites for the transformation of nuclear material: enrichment of fissile material; fuel elements fabrication, burning, spent fuel reprocessing and waste management. d) Off-shore power plant siting and the creation of an artificial island. (A.F.)

  9. High Efficiency Nuclear Power Plants Using Liquid Fluoride Thorium Reactor Technology

    Science.gov (United States)

    Juhasz, Albert J.; Rarick, Richard A.; Rangarajan, Rajmohan

    2009-01-01

    An overall system analysis approach is used to propose potential conceptual designs of advanced terrestrial nuclear power plants based on Oak Ridge National Laboratory (ORNL) Molten Salt Reactor (MSR) experience and utilizing Closed Cycle Gas Turbine (CCGT) thermal-to-electric energy conversion technology. In particular conceptual designs for an advanced 1 GWe power plant with turbine reheat and compressor intercooling at a 950 K turbine inlet temperature (TIT), as well as near term 100 MWe demonstration plants with TITs of 950 and 1200 K are presented. Power plant performance data were obtained for TITs ranging from 650 to 1300 K by use of a Closed Brayton Cycle (CBC) systems code which considered the interaction between major sub-systems, including the Liquid Fluoride Thorium Reactor (LFTR), heat source and heat sink heat exchangers, turbo-generator machinery, and an electric power generation and transmission system. Optional off-shore submarine installation of the power plant is a major consideration.

  10. The tidal influence on oil and gas emissions from an abandoned oil well: Nearshore Summerland, California

    International Nuclear Information System (INIS)

    Leifer, Ira; Wilson, Ken

    2007-01-01

    Oil and gas emissions were quantified for natural and human sources in nearshore waters off Summerland, California through deployment of custom designed collection tents. Seepage was measured at a repeatedly abandoned well, on the seabed from a caisson located along the historical location of the Treadwell Wharf, where the world's first off-shore oil wells were drilled at the end of the 19th century. Seepage rates at the capped T-10 Well, located in ∼5 m water, showed high correlation to tides. Site emissions were 2.4 and 38.7 L day -1 oil and gas, respectively. Emissions were measured from two areas of seepage at the T-10 Well Site. Oil and gas ratios were inversely correlated between the two seepage areas, demonstrating connectivity. Data were interpreted in terms of an electronic circuit model of seepage with respect to the time lag between local low tide and peak oil emissions

  11. KM3NeT tower data acquisition and data transport electronics

    Science.gov (United States)

    Nicolau, C. A.; Ameli, F.; Biagioni, A.; Capone, A.; Frezza, O.; Lonardo, A.; Masullo, R.; Mollo, C. M.; Orlando, A.; Simeone, F.; Vicini, P.

    2016-04-01

    In the framework of the KM3Net European project, the production stage of a large volume underwater neutrino telescope has started. The forthcoming installation includes 8 towers and 24 strings, that will be installed 100 km off-shore Capo Passero (Italy) at 3500 m depth. The KM3NeT tower, whose layout is strongly based on the NEMO Phase-2 prototype tower deployed in March 2013, has been re-engineered and partially re-designed in order to optimize production costs, power consumption, and usability. This contribution gives a description of the main electronics, including front-end, data transport and clock distribution system, of the KM3NeT tower detection unit.

  12. KM3NeT tower data acquisition and data transport electronics

    Directory of Open Access Journals (Sweden)

    Nicolau C.A.

    2016-01-01

    Full Text Available In the framework of the KM3Net European project, the production stage of a large volume underwater neutrino telescope has started. The forthcoming installation includes 8 towers and 24 strings, that will be installed 100 km off-shore Capo Passero (Italy at 3500 m depth. The KM3NeT tower, whose layout is strongly based on the NEMO Phase-2 prototype tower deployed in March 2013, has been re-engineered and partially re-designed in order to optimize production costs, power consumption, and usability. This contribution gives a description of the main electronics, including front-end, data transport and clock distribution system, of the KM3NeT tower detection unit.

  13. Phasor measurement of wind power plant operation in Eastern Denmark

    DEFF Research Database (Denmark)

    Rasmussen, Joana; Nielsen, Arne Hejde

    2007-01-01

    Four Phasor Measurement Units (PMUs) record continuously voltage and current phasors in the 400 kV and 132 kV transmission system of Eastern Denmark. The abstract evaluates the unique concept for power system monitoring using PMUs. It focuses on utilization of synchronized phasor measurements from...... Nysted off-shore wind farm during a severe storm in 2005. The wind speeds during the event were so high, that Nysted offshore wind farm as well as a significant amount of on-land wind production in Denmark was disconnected from the grid. The PMU analysis illustrates that PMUs complement the traditional...... measurements from a traditional SCADA system. The case reveals the close relation between voltages, power flows and voltage phase angles over a wide area....

  14. Carbon market: to which emission quota to devote?

    International Nuclear Information System (INIS)

    Chandes, Camille

    2013-01-01

    As the European Emission Trading Scheme (ETS) is entering its third phase, an article discusses uncertainties and problems regarding this system: CO 2 price is falling down, French industrials do not know which quantity they'll have to buy for their installations, and even some frauds and swindles occurred. Besides the fact that the low level of carbon price is not a motivation for investors, the market is criticised for its imbalance between supply and demand. As some industrials find the costs too high, some sectors may consider off-shoring their activities. Some actors suggest the creation of a central bank of carbon. Countries are using the product of emission bidding in different sectors: housing rehabilitation in France, industry support in Germany, reduction of budget deficit in Italy and Great Britain, construction of passive dwellings in Czech Republic

  15. AECL hot-cell facilities and post-irradiation examination services

    International Nuclear Information System (INIS)

    Schankula, M.H.; Plaice, E.L.; Woodworth, L.G.

    1995-01-01

    This paper presents an overview of the post-irradiation examination (PIE) services available at AECL's hot-cell facilities (HCF). The HCFs are used primarily to provide PIE support for operating CANDU power reactors in Canada and abroad, and for the examination of experimental fuel bundles and core components irradiated in research reactors at the Chalk River Laboratories (CRL) and off-shore. A variety of examinations and analysis are performed ranging from non-destructive visual and dimensional inspections to detailed optical and scanning electron microscopic examinations. Several hot cells are dedicated to mechanical property testing of structural materials and to determine the fitness-for-service of reactor core components. Facility upgrades and the development of innovative examination techniques continue to improve AECL's PIE capabilities. (author)

  16. Triboelectric Charging at the Nanostructured Solid/Liquid Interface for Area-Scalable Wave Energy Conversion and Its Use in Corrosion Protection.

    Science.gov (United States)

    Zhao, Xue Jiao; Zhu, Guang; Fan, You Jun; Li, Hua Yang; Wang, Zhong Lin

    2015-07-28

    We report a flexible and area-scalable energy-harvesting technique for converting kinetic wave energy. Triboelectrification as a result of direct interaction between a dynamic wave and a large-area nanostructured solid surface produces an induced current among an array of electrodes. An integration method ensures that the induced current between any pair of electrodes can be constructively added up, which enables significant enhancement in output power and realizes area-scalable integration of electrode arrays. Internal and external factors that affect the electric output are comprehensively discussed. The produced electricity not only drives small electronics but also achieves effective impressed current cathodic protection. This type of thin-film-based device is a potentially practical solution of on-site sustained power supply at either coastal or off-shore sites wherever a dynamic wave is available. Potential applications include corrosion protection, pollution degradation, water desalination, and wireless sensing for marine surveillance.

  17. Hydrocarbon distributions in sediments of the open area of the Arabian Gulf following the 1991 Gulf War oil spill

    International Nuclear Information System (INIS)

    Al-Lihaibi, S.S.; Ghazi, S.J.

    1997-01-01

    Surface sediments collected from the open area of the Arabian Gulf were analysed for total petroleum hydrocarbons and specific aliphatic hydrocarbon components in order to provide information on the extent of oil contamination and the degree of weathering of the spilled oil following the Gulf War. The surface distribution of the petroleum hydrocarbons showed an increasing trend towards the north-east, and among the individual transects there was a pronounced increasing trend towards the north-west direction. Despite off-shore oil-related activities as well as a potential impact from the 1991 oil spill, the concentrations of petroleum hydrocarbons in the study area were relatively low. This finding may be attributed to the effectiveness of weathering processes. (author)

  18. Studies on the radioactive contamination of the sea

    International Nuclear Information System (INIS)

    Bernhard, M.

    1974-12-01

    The annual Report of the CNEN-Euratom Association Contract is presented. The program laid down in this contract calls for the studies of the factors which influence the uptake, accumulation and loss of radioisotopes by different inorganic and organic constituents of the marine environment. The program is divided into two parts: a) the investigation of relevant radioecological and ecological factors in nature and under laboratory conditions; b) the investigation of the outfall area off-shore of the CNEN-Trisaia Centre in the Gulf of Taranto (fuel-reprocessing plant). The task of carrying out this program has been divided between six groups: Chemistry, Botany, Zooplankton, Fisheries biology, Microbiology and Special developments. An account is given of the results obtained in 1972

  19. Dynamic modelling of VSC-HVDC for connection of offshore wind farms

    DEFF Research Database (Denmark)

    Rios, Bardo; Garcia-Valle, Rodrigo

    2011-01-01

    A VSC-HVDC (Voltage Source Converter – High Voltage Direct Current) dynamic model with a set of control strategies is developed in DIgSILENT Power-Factory with the objective of analyzing the converter’s operating capability for grid support during grid faults. The investigation is carried out based...... on a 165 MW offshore wind farm with induction generators and a Low Voltage Ride-Through solution of the offshore wind turbines and Static Voltage Compensator units in the point of connection with a grid represented by a reduced four-generator power grid model. VSC-HVDC promises to be a reliable alternative...... solution for interconnection with off-shore wind farms as they become larger, with a higher installed power capacity, increased number of wind turbines, and geographically situated at larger distances from suitable connection points in the transmission grids....

  20. Navigation errors encountered using weather-mapping radar for helicopter IFR guidance to oil rigs

    Science.gov (United States)

    Phillips, J. D.; Bull, J. S.; Hegarty, D. M.; Dugan, D. C.

    1980-01-01

    In 1978 a joint NASA-FAA helicopter flight test was conducted to examine the use of weather-mapping radar for IFR guidance during landing approaches to oil rig helipads. The following navigation errors were measured: total system error, radar-range error, radar-bearing error, and flight technical error. Three problem areas were identified: (1) operational problems leading to pilot blunders, (2) poor navigation to the downwind final approach point, and (3) pure homing on final approach. Analysis of these problem areas suggests improvement in the radar equipment, approach procedure, and pilot training, and gives valuable insight into the development of future navigation aids to serve the off-shore oil industry.

  1. Making waves with undersea (radioactive waste) disposal

    International Nuclear Information System (INIS)

    Milne, Roger.

    1987-01-01

    Following the Government's decision to halt the search for land-based disposal sites for low-level radioactive wastes, the search for alternative means of disposal of low- and intermediate-level wastes continues. Off-shore sites now seems to be the most likely. Two approaches are mentioned. The first is that proposed by Consolidated Environmental Technologies Ltd., to sink a shaft 15 metre in diameter under the seabed in an area of tectonic stability, possibly off Lincolnshire. The shaft could be 3000 metres deep. Waste packages and large decommissioning items would be lowered in from a giant barge. This would be expensive but environmentally more acceptable than the other approach. That is to tunnel out from the land and store the waste offshore, below the seabed. (U.K.)

  2. Storage Rings for Science with: Electron-Positron Collisions, Hadron Collisions and Synchrotron Light

    International Nuclear Information System (INIS)

    Ozaki, S.

    2009-01-01

    The author is honored to receive the 2009 Robert Wilson Prize and the recognition that comes with it. The citation for the prize reads, 'For his outstanding contribution to the design and construction of accelerators that has led to the realization of major machines for fundamental science on two continents and his promotion of international collaboration.' In this article, he will discuss the two construction projects, which he led, one (TRISTAN e + e - Collider at KEK) in Japan and the other (RHIC at BNL) in the USA, covering project issues and lessons learned from these projects. Although both of them were built on separate continents, it is interesting to note that they are both built on long off-shore islands. He will also add comments on his recent engagement in the development of the Conceptual Design for the National Synchrotron Light Source II (NSLS-II).

  3. Wind power - An impulse or just frustration for business?

    International Nuclear Information System (INIS)

    Wellstein, J.

    2005-01-01

    This article deals with the question raised as to whether the development of wind power can provide an impulse for industry. The answers provided by Markus Geissmann from the Swiss Federal Office of Energy (SFOE) and Robert Horbaty, head of 'Suisse Eole' - a Swiss society that supports the use of wind energy - are presented in the form of an interview. In particular, the fact that certain Swiss manufacturers have established themselves in the international wind energy market is discussed - in spite of the relatively low proportion of wind energy actually generated in Switzerland. The various factors influencing both on-shore and off-shore wind-power installations are discussed. The products and services offered are discussed and also the up-and-coming market for the replacement of older wind-power installations is looked at

  4. Concept Evaluation for Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

    2013-01-01

    The yaw system is the subsystem on a wind turbine which ensures that the rotor plane of the turbine always is facing the wind direction. Studies from [1] show that a soft yaw system may be utilized to dampen the loads in the wind turbine structure. The soft yaw system operates much like...... investigation. Loads and yaw demands are based on the IEC 61400-1 standard for wind turbine design, and the loads for this examination are extrapolated from the HAWC2 aeroelastic design code. The concepts are based on a 5 MW off-shore turbine....... a suspension system on a car, leading the loads away from the turbine structure. However, to realize a soft hydraulic yaw system a new design concept must be found. As a part of the development of the new concept a preliminary concept evaluation has been conducted, evaluating seven different hydraulic yaw...

  5. Trends in Modelling, Simulation and Design of Water Hydraulic Systems – Motion Control and Open-Ended Solutions

    DEFF Research Database (Denmark)

    Conrad, Finn

    2006-01-01

    is on the advantages using ordinary tap water and the range of application areas are illustrated with examples, in particular within the food processing industry, humidification operations, water mist systems for fire fighting, high water pressure cleaners, water moisturising systems for wood processing, lumber drying...... is that the components operate with pure water from the tap without additives of any kind. Hence water hydraulics takes the benefit of pure water as fluid being environmentally friendly, easy to clean sanitary design, non-toxic, non-flammable, inexpensive, readily available and easily disposable. The low-pressure tap......, dedicated pumps and accessories running with sea-water as fluid are available. A unique solution is to use reverse osmosis to generate drinking water from sea-water, and furthermore for several off-shore applications. Furthermore, tap water hydraulic components of the Nessie® family and examples of measured...

  6. Trends in Design of Water Hydraulics

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    ordinary tap water and the range of application areas are illustrated with examples, in particular within the food processing industry, humidification operations, water mist systems for fire fighting, high water pressure cleaners, water moisturising systems for wood processing, lumber drying process...... operate with pure water from the tap without additives of any kind. Hence water hydraulics takes the benefit of pure water as fluid being environmentally friendly, easy to clean sanitary design, non-toxic, non-flammable, inexpensive, readily available and easily disposable. The low-pressure tap water...... and accessories running with sea-water as fluid are available. A unique solution is to use reverse osmosis to generate drinking water from sea-water, and furthermore for several off-shore applications. Furthermore, tap water hydraulic components of the Nessie® family and examples of measured performance...

  7. Target objectives in Spanish Marine Science within the European context (2003-2007

    Directory of Open Access Journals (Sweden)

    Beatriz Morales-Nin

    2009-03-01

    Full Text Available The analysis of the marine projects funded by the Spanish RTD funding agency between 2003 and 2007 in the framework of the European policies, showed that although the funds available have increased (232 projects and 33 Million € from 2003 to 2007 there are still research and strategic areas that are not covered. The relevance of marine related services and economic revenues for Spain requires that a strategy is developed to address the challenges that are emerging due to the growing competing uses of the sea, which include maritime transport, fishing, aquaculture, leisure activities, off-shore energy production and other forms of seabed exploitation. By helping to develop a more sophisticated understanding of the impact of human activities on marine systems, scientific research and technology may provide the key to carrying out sea-based activities without degrading the environment, and to predicting and mitigating as far as possible the effects of climate change.

  8. Effects of intensive mariculture on sediment biochemistry

    DEFF Research Database (Denmark)

    Pusceddu, Antonio; Fraschetti, Simonetta; Mirto, Simone

    2007-01-01

    The exponential growth of off-shore mariculture that has occurred worldwide over the last 10 years has raised concern about the impact of the waste produced by this industry on the ecological integrity of the sea bottom. Investigations into this potential source of impact on the biochemistry...... of the sea floor have provided contrasting results, and no compelling explanations for these discrepancies have been provided to date. To quantify the impact of fish-farm activities on the biochemistry of sediments, we have investigated the quantity and biochemical composition of sediment organic matter...... regions, with the exception of seagrass sediments in Spain, the biochemistry of the sediments showed significant differences between the control and fish-farm locations. However, the variables explaining the differences observed varied among the regions and between habitats, suggesting idiosyncratic...

  9. The Coral Reefs Optimization Algorithm: A Novel Metaheuristic for Efficiently Solving Optimization Problems

    Science.gov (United States)

    Salcedo-Sanz, S.; Del Ser, J.; Landa-Torres, I.; Gil-López, S.; Portilla-Figueras, J. A.

    2014-01-01

    This paper presents a novel bioinspired algorithm to tackle complex optimization problems: the coral reefs optimization (CRO) algorithm. The CRO algorithm artificially simulates a coral reef, where different corals (namely, solutions to the optimization problem considered) grow and reproduce in coral colonies, fighting by choking out other corals for space in the reef. This fight for space, along with the specific characteristics of the corals' reproduction, produces a robust metaheuristic algorithm shown to be powerful for solving hard optimization problems. In this research the CRO algorithm is tested in several continuous and discrete benchmark problems, as well as in practical application scenarios (i.e., optimum mobile network deployment and off-shore wind farm design). The obtained results confirm the excellent performance of the proposed algorithm and open line of research for further application of the algorithm to real-world problems. PMID:25147860

  10. ENIDINE: Vibration and seismic isolation technologies for power generation station applications

    International Nuclear Information System (INIS)

    Zemanek, T.A.

    1994-01-01

    ENIDINE Inc. is a world leader in the design and manufacture of shock and vibration mounts. Founded in 1966, the company has two manufacturing facilities, employs over 300 people and supports a worldwide network of distributors and representatives. ENIDINE Inc. is part of the ENIDINE Corporate Group which owns a number of companies that design and manufacture Hydraulic/Pneumatic cylinders, Electromechanical devices, Hydraulic Control Valves and a number of Industrial Distribution companies throughout Europe. In total, the ENIDINE Corporate Group has over 900 employees with annual sales of over $100 million. ENIDINE shock and vibration mounts are used to isolate the vibration of missiles from their guidance systems, pumps from hospital operating equipment and off shore oil rigs, from the shock energy of waves in the North Sea. ENIDINE products can be found on all Boeing and McDonnell Douglas aircraft, as well as many electronic and weapons systems on board Navy ships

  11. Hydrogen and energy utilities

    Energy Technology Data Exchange (ETDEWEB)

    Hustadt, Daniel [Vattenfall Europe Innovation GmbH (Germany)

    2010-07-01

    Renewable electricity generation plays one major role with the biggest share being wind energy. At the end of the year 2009 a wind power plant capacity of around 26 GW was installed in Germany. Several outlooks come to the conclusion that this capacity can be doubled in ten years (compare Figure 1). Additionally the German government has set a target of 26 GW installed off-shore capacity in North and Baltic Sea until 2030. At Vattenfall only a minor percentage of the electricity production comes from wind power today. This share will be increased up to 12% until 2030 following Vattenfall's strategy 'Making Electricity Clean'. This rapid development of wind power offers several opportunities but also means some challenges to Utilities. (orig.)

  12. Utilization of gas micro turbines in the PETROBRAS remote unattended stations; Utilizacao de microturbinas a gas nas instalacoes desassistidas da PETROBRAS

    Energy Technology Data Exchange (ETDEWEB)

    Pavinatto, Eduardo F.; Salles, Fabio P.; Peres, Marcelo B.; Pereira, Leandro S.; Reis, Paulo F.I. dos [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    This paper presents PETROBRAS experience in the utilization of gas micro turbines in the production of gas and oil located in off-shore fields and gas metering stations of the transportation system. Available alternatives will be presented for the electrical power supply of these units and they will be outstanding the acquired benefits by using gas micro turbines. Also will be presented the performance test results conducted by CENPES technical staff. Finally, we will present an analysis of the observed acting of these equipment after they have been installed in the units of PETROBRAS under the reliability point of view, maintenance rates, adaptation to the local environmental conditions, behavior of the electric system and operational versatility. (author)

  13. Numerical and experimental investigations of submarine groundwater discharge to a coastal lagoon

    DEFF Research Database (Denmark)

    Haider, Kinza

    The main goal of this study is to understand and estimate the amount of submarine groundwater discharge into Ringkøbing Fjord from shallow and deep aquifer systems at the Eastern shoreline from Ringkøbing catchment in Western Denmark. In order to accomplish this objective, the study was initiated...... of the groundwater discharge occurred near the shoreline of the lagoon, but also off-shore discharge from deep confined aquifers system occurred at places where confining clay layers are eroded by buried valleys. The simulated fresh groundwater discharge was a non-negligible component, 59 % of recharge on the lagoon...... and 6 % of river input into the lagoon. This large-scale study was the motivation to conduct field investigation techniques in order to understand the dynamic processes in the near-shore environment. Field campaigns were conducted every two months in order to understand the seasonal groundwater...

  14. Interdisciplinary seminar on nondestructive testing and fracture mechanics. Lectures

    International Nuclear Information System (INIS)

    1998-01-01

    The proceedings volume contains 17 lectures presented at a DGZfP seminar held in Berlin/Germany, 2-3 November 1998. Fracture mechanics data are of interest with respect to determining maximum permissible limits for non-destructive materials evaluation, and as quantitative NDE test results indicating existing materials flaws in a system component, delivering information for assessement of remaining service life and safety risks. The topics of lectures are: Quality concepts for welded joints; NDE for service life assessment of engine components, shown for evaluation of engine pales and disks; NDE and crack detection at pressurized gas cylinders; fracture mechanics requirements for NDE in nuclear installations, discussion of practical examples (T. Seidenkranz); failure of off-shore constructions seen in the light of a novel fracture mechanics technical code. (orig./CB) [de

  15. Habitat selection by grey mullets (Osteichthyes: Mugilidae in Mediterranean estuaries: the role of salinity

    Directory of Open Access Journals (Sweden)

    Luis Cardona

    2006-09-01

    Full Text Available A stratified study of microhabitat use by grey mullet on the island of Minorca (Balearic archipelago, western Mediterranean showed that the distribution of all the species was dramatically affected by salinity. Sites with a salinity level under 15 were positively selected in spring and summer by those species whose growth performance was the best in oligomesohaline water (Liza ramado and Mugil cephalus but also by a species whose growth was not affected by salinity (Chelon labrosus. Liza aurata concentrated in polyhaline and euhaline sites, where growth was improved, a pattern also exhibited by Liza saliens. Both species avoided fresh water sites all year round. As a consequence, community structure was correlated with salinity. The above reported electivity patterns often disappeared in autumn, when most grey mullets migrate off-shore.

  16. AECL hot-cell facilities and post-irradiation examination services

    International Nuclear Information System (INIS)

    Schankula, M.H.; Plaice, E.L.; Woodworth, L.G.

    1998-04-01

    This paper presents an overview of the post-irradiation examination (PIE) services available at AECL's hot-cell facilities (HCF). The HCFs are used primarily to provide PIE support for operating CANDU power reactors in Canada and abroad, and for the examination of experimental fuel bundles and core components irradiated in research reactors at the Chalk River Laboratories (CRL) and off-shore. A variety of examinations and analyses are performed ranging from non-destructive visual and dimensional inspections to detailed optical and scanning electron microscopic examinations. Several hot cells are dedicated to mechanical property testing of structural materials and to determine the fitness-for-service of reactor core components. Facility upgrades and the development of innovative examination techniques continue to improve AECL's PIE capabilities. (author)

  17. Standardizing the performance evaluation of short-term wind prediction models

    DEFF Research Database (Denmark)

    Madsen, Henrik; Pinson, Pierre; Kariniotakis, G.

    2005-01-01

    Short-term wind power prediction is a primary requirement for efficient large-scale integration of wind generation in power systems and electricity markets. The choice of an appropriate prediction model among the numerous available models is not trivial, and has to be based on an objective...... evaluation of model performance. This paper proposes a standardized protocol for the evaluation of short-term wind-poser preciction systems. A number of reference prediction models are also described, and their use for performance comparison is analysed. The use of the protocol is demonstrated using results...... from both on-shore and off-shore wind forms. The work was developed in the frame of the Anemos project (EU R&D project) where the protocol has been used to evaluate more than 10 prediction systems....

  18. Prediction models for wind speed at turbine locations in a wind farm

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas; Soltani, Mohsen

    2011-01-01

    In wind farms, individual turbines disturb the wind field by generating wakes that influence other turbines in the farm. From a control point of view, there is an interest in dynamic optimization of the balance between fatigue and production, and an understanding of the relationship between turbines...... on standard turbine measurements such as rotor speed and power produced, an effective wind speed, which represents the wind field averaged over the rotor disc, is derived. The effective wind speed estimator is based on a continuous–discrete extended Kalman filter that takes advantage of nonlinear time varying...... on the result related to effective wind speed, it is possible to predict wind speeds at neighboring turbines, with a separation of over 700 m, up to 1 min ahead reducing the error by 30% compared with a persistence method. The methodological results are demonstrated on data from an off-shore wind farm...

  19. Synchronisation of two separate zones in a standalone microgrid

    Directory of Open Access Journals (Sweden)

    Ying-Yi Hong

    2017-06-01

    Full Text Available Standalone microgrids that comprise distributed generation sources (DGSs or energy storage systems (ESSs exist on off-shore islands or remote areas. When a fault occurs in a standalone microgrid, the microgrid is separated into several zones with pre-specified DGS or ESS supplying power to local loads. After the fault is cleared, the three-phase voltages and frequencies may differ among these zones. To restore the original microgrid topology, these zones must be reconnected to each other by synchronisation. A synchronisation controller of the DGS/ESS that accounts for slightly different three-phase voltages and frequencies in two separate zones is presented. The Clark transform and Mamdani fuzzy rules are used to implement the controller, providing fast and seamless synchronisation. Simulation results using a standalone microgrid show the practical applicability of the proposed method.

  20. Public Hearing or `Hearing Public'? An Evaluation of the Participation of Local Stakeholders in Environmental Impact Assessment of Ghana's Jubilee Oil Fields

    Science.gov (United States)

    Bawole, Justice Nyigmah

    2013-08-01

    This article investigates the involvement of local stakeholders in the environmental impact assessment (EIA) processes of Ghana's first off-shore oil fields (the Jubilee fields). Adopting key informants interviews and documentary reviews, the article argues that the public hearings and the other stakeholder engagement processes were cosmetic and rhetoric with the view to meeting legal requirements rather than a purposeful interest in eliciting inputs from local stakeholders. It further argues that the operators appear to lack the social legitimacy and social license that will make them acceptable in the project communities. A rigorous community engagement along with a commitment to actively involving local stakeholders in the corporate social responsibility (CSR) programmes of the partners may enhance the image of the partners and improve their social legitimacy. Local government agencies should be capacitated to actively engage project organisers; and government must mitigate the impact of the oil projects through well-structured social support programmes.

  1. Heterogeneity of the North Atlantic oceanic lithosphere based on integrated analysis of GOCE satellite gravity and geological data

    DEFF Research Database (Denmark)

    Barantseva, Olga; Artemieva, Irina; Thybo, Hans

    2015-01-01

    harmonics caused by deep density structure of the Earth (the core and the lower mantle). The gravity effect of the upper mantle is calculated after the subtracting gravity effect of the crust for two crustal models, including seismic and borehole data on sediments. We use a recent regional seismic model......We present the results of modeling of the gravity and density structure of the upper mantle for the off-shore area of the North Atlantic region. The crust and upper mantle of the region is expected to be anomalous: a part of the region affected by the Icelandic plume has an anomalously shallow...... the gravity and density structure of the upper mantle from satellite gravity data. The calculations are based on interpretation of GOCE gravity satellite data for the North Atlantics. To separate gravity signal, responsible for density anomalies within the crust and upper mantle, we subtract the lower...

  2. Biological Select Agents and Toxins: Risk-Based Assessment Management and Oversight.

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, LouAnn Crawford; Brodsky, Benjamin H.

    2016-12-01

    Sandia National Laboratories' International Biological and Chemical Threat Reduction (SNL/IBCTR) conducted, on behalf of the Federal Select Agent Program (FSAP), a review of risk assessment in modern select agent laboratories. This review and analysis consisted of literature review, interviews of FSAP staff, entities regulated by FSAP, and deliberations of an expert panel. Additionally, SNL/IBCTR reviewed oversight mechanisms used by industries, US agencies, and other countries for high-consequence risks (e.g, nuclear, chemical, or biological materials, aviation, off-shore drilling, etc.) to determine if alternate oversight mechanisms existed that might be applicable to FSAP oversight of biological select agents and toxins. This report contains five findings, based on these reviews and analyses, with recommendations and suggested actions for FSAP to consider.

  3. A study on the diagnosis for power transformer by ultrasonic wave detection(2)

    International Nuclear Information System (INIS)

    Lee, Sang Guk; Gil Doo Song

    2003-01-01

    The objectives of this study is to develop a device which could diagnose periodically the degradation of power transformer using ultrasonic signal through ultrasonic transducer attached surface of power transformer. And also it makes possible to reduce power failure time due to the power transformer fault and makes power system more reliable. Ultrasonic diagnostic device for power transformer was developed through this study. The developed device will contributed to early detection of fault and its location in the power transformer while it is operated, and also to extension of transformer life cycle, localization of this device will be reduced it's cost down compared with off shore. This device consisted of a new diagnostic algorithm is well suited for the power transformer which could found out some fault during the operation of on line monitoring system. This system could be extended to the general industrial plant utilizing the accumulated diagnostic technique.

  4. A study on the diagnosis for power transformer by Ultrasonic wave detection (2)

    International Nuclear Information System (INIS)

    Lee, Sang Guk; Gil, Doo Song

    2003-01-01

    The objectives of this study is to develop a device which could diagnosis periodically the degradation of power transformer using ultrasonic signal through ultrasonic transducer attached surface of power transformer. And also it makes possible to reduce power failure time due to the power transformer fault and makes power system more reliable. Ultrasonic diagnostic device for power transformer was developed through this study. The developed device will contributed to early detection of fault and its location in the power transformer while it is operated, and also to extension of transformer life cycle, localization of this device will be reduced it's cost down compared with off shore. This device consisted of a new diagnostic algorithm is well suited for the power transformer which could found out some fault during the operation of on line monitoring system. This system could be extended to the general industrial plant utilizing the accumulated diagnostic technique.

  5. Blyth Harbour wind farm - operational aspects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This report is the last in a series of seven on various aspects of the monitoring and evaluation of the Blyth Northumberland off-shore wind farm project. The wind farm was the first to be built in the UK: it consists of two 2MW wind turbines about 1 km from the coast in water of depth 5-6 m. The subject of this report is the actual performance of the wind turbine relative to predicted performance. The study showed up the problems of operating a wind farm at sea and the need for comprehensive testing before installation. The problems encountered were numerous but in no case major. A lightning strike destroyed a turbine blade (for which no replacement was readily available) and there was a cable fault caused by installation deficiencies. Better planning could have avoided lengthy shutdowns. The report covers the availability of the turbines and performance of ancillary equipment.

  6. Computational mechanics of nonlinear response of shells

    Energy Technology Data Exchange (ETDEWEB)

    Kraetzig, W.B. (Bochum Univ. (Germany, F.R.). Inst. fuer Statik und Dynamik); Onate, E. (Universidad Politecnica de Cataluna, Barcelona (Spain). Escuela Tecnica Superior de Ingenieros de Caminos) (eds.)

    1990-01-01

    Shell structures and their components are utilized in a wide spectrum of engineering fields reaching from space and aircraft structures, pipes and pressure vessels over liquid storage tanks, off-shore installations, cooling towers and domes, to bodyworks of motor vehicles. Of continuously increasing importance is their nonlinear behavior, in which large deformations and large rotations are involved as well as nonlinear material properties. The book starts with a survey about nonlinear shell theories from the rigorous point of view of continuum mechanics, this starting point being unavoidable for modern computational concepts. There follows a series of papers on nonlinear, especially unstable shell responses, which draw computational connections to well established tools in the field of static and dynamic stability of systems. Several papers are then concerned with new finite element derivations for nonlinear shell problems, and finally a series of authors contribute to specific applications opening a small window of the above mentioned wide spectrum. (orig./HP) With 159 figs.

  7. Experiments on the WavePiston, Wave Energy Converter

    DEFF Research Database (Denmark)

    Angelelli, E.; Zanuttigh, B.; Kofoed, Jens Peter

    2011-01-01

    This paper analyses the performance of a new Wave Energy Converter (WEC) of the Oscillating Water Column type (OWC), named WavePiston. This near-shore floating device is composed of plates (i.e. energy collectors) sliding around a cylinder, that is placed perpendicular to the shore. Tests...... in the wave basin at Aalborg University allowed to investigate power production in the North Sea typical wave climate, with varying design parameters such as plate dimensions and their mutual distance. The power produced per meter by each collector is about the 5% of the available wave power. Experimental...... results and survivability considerations suggest that the WavePiston would be particularly suited for installations in milder seas. An example application is therefore presented in the Mediterranean Sea, off-shore the island of Sicily. In this case, each collector harvests the 10% of the available wave...

  8. Statistical Analysis of Power Production from OWC Type Wave Energy Converters

    DEFF Research Database (Denmark)

    Martinelli, L.; Zanuttigh, B.; Kofoed, Jens Peter

    2009-01-01

    Oscillating Water Column based wave energy plants built so far have experienced a low efficiency in the conversion of the bidirectional oscillating flow. A new concept is considered here, the LeanCon Wave Energy Converter (WEC), that unifies the flow direction by use of non-return valves...... (wave period, wave height). Average performance and stochastic variability is thus obtained for any sea state and therefore also for the annual wave climate of interest. An example application of a LeanCon unit is carried out for a location off-shore Cagliari (Italy). Conclusions provide economic......, into a unidirectional flow, making the use of more efficient air turbines possible. Hereby, a more steady flow is also obtained. The general objective of this note is to examine, the power take off (PTO) efficiency under irregular wave conditions, for WECs with flow redirection. Final practical aim is to identify...

  9. Review of DC System Technologies for Large Scale Integration of Wind Energy Systems with Electricity Grids

    Directory of Open Access Journals (Sweden)

    Sheng Jie Shao

    2010-06-01

    Full Text Available The ever increasing development and availability of power electronic systems is the underpinning technology that enables large scale integration of wind generation plants with the electricity grid. As the size and power capacity of the wind turbine continues to increase, so is the need to place these significantly large structures at off-shore locations. DC grids and associated power transmission technologies provide opportunities for cost reduction and electricity grid impact minimization as the bulk power is concentrated at single point of entry. As a result, planning, optimization and impact can be studied and carefully controlled minimizing the risk of the investment as well as power system stability issues. This paper discusses the key technologies associated with DC grids for offshore wind farm applications.

  10. Acoustic multivariate condition monitoring - AMCM

    Energy Technology Data Exchange (ETDEWEB)

    Rosenhave, P E [Vestfold College, Maritime Dept., Toensberg (Norway)

    1998-12-31

    In Norway, Vestfold College, Maritime Department presents new opportunities for non-invasive, on- or off-line acoustic monitoring of rotating machinery such as off-shore pumps and diesel engines. New developments within acoustic sensor technology coupled with chemometric data analysis of complex signals now allow condition monitoring of hitherto unavailable flexibility and diagnostic specificity. Chemometrics paired with existing knowledge yields a new and powerful tool for condition monitoring. By the use of multivariate techniques and acoustics it is possible to quantify wear and tear as well as predict the performance of working components in complex machinery. This presentation describes the AMCM method and one result of a feasibility study conducted onboard the LPG/C `Norgas Mariner` owned by Norwegian Gas Carriers as (NGC), Oslo. (orig.) 6 refs.

  11. Power from the seas - Wave energy has a big future

    International Nuclear Information System (INIS)

    Schenler, W.

    2008-01-01

    This article takes a look at how the energy of the oceans' waves can become an important source of energy. The generation of the energy contained in waves as an indirect form of solar energy is described. The energy potential offered is quoted as being high in the Atlantic near England and Scotland. The article goes on the discuss the technical potential of this form of renewable energy and provides a map showing this. Financial aspects and economic potentials are discussed. Effects on the environment are also discussed. The on-shore and off-shore technologies that can be used to capture wave energy are described and discussed, as is the combination of power production from wind and waves

  12. Acoustic multivariate condition monitoring - AMCM

    Energy Technology Data Exchange (ETDEWEB)

    Rosenhave, P.E. [Vestfold College, Maritime Dept., Toensberg (Norway)

    1997-12-31

    In Norway, Vestfold College, Maritime Department presents new opportunities for non-invasive, on- or off-line acoustic monitoring of rotating machinery such as off-shore pumps and diesel engines. New developments within acoustic sensor technology coupled with chemometric data analysis of complex signals now allow condition monitoring of hitherto unavailable flexibility and diagnostic specificity. Chemometrics paired with existing knowledge yields a new and powerful tool for condition monitoring. By the use of multivariate techniques and acoustics it is possible to quantify wear and tear as well as predict the performance of working components in complex machinery. This presentation describes the AMCM method and one result of a feasibility study conducted onboard the LPG/C `Norgas Mariner` owned by Norwegian Gas Carriers as (NGC), Oslo. (orig.) 6 refs.

  13. Environmental protection in exploration and production by AGIP

    International Nuclear Information System (INIS)

    Dossena, G.; Di Luise, G.; Ceffa, L.

    1991-01-01

    This paper provides a panorama of environmental protection activities being undertaken by AGIP (Italian General Petroleum Company). The Company has developed a wide-ranging program based on 20 years experience in world-wide on- and off-shore exploration and production. The research studies on technologically innovative on-site waste management, noise abatement and subsidence control and monitoring techniques are co-operative efforts involving the joint participation of national research institutions, universities and leading international petroleum companies. Given the intense oil carrier traffic along Italy's tourism dependent coastlines, one of the key projects is the creation of a national emergency plan to deal with oil spills. AGIP is also actively involved in the training of national and foreign site personnel in environmental protection techniques

  14. The Statistical Distribution of Turbulence Driven Velocity Extremes in the Atmosperic Boundary Layer cartwright/Longuet-Higgins Revised

    DEFF Research Database (Denmark)

    Hansen, Kurt Schaldemose

    2007-01-01

    The statistical distribution of extreme wind excursions above a mean level, for a specified recurrence period, is of crucial importance in relation to design of wind sensitive structures. This is particularly true for wind turbine structures. Based on an assumption of a Gaussian "mother......" distribution, Cartwright and Longuet-Higgens [1] derived an asymptotic expression for the distribution of the largest excursion from the mean level during an arbitrary recurrence period. From its inception, this celebrated expression has been widely used in wind engineering (as well as in off-shore engineering...... associated with large excursions from the mean [2]. Thus, the more extreme turbulence excursions (i.e. the upper tail of the turbulence PDF) seem to follow an Exponential-like distribution rather than a Gaussian distribution, and a Gaussian estimate may under-predict the probability of large turbulence...

  15. Energy change in the industrial society

    International Nuclear Information System (INIS)

    Hebeler, Timo; Hendler, Reinhard; Proelss, Alexander; Reiff, Peter

    2014-01-01

    The present volume contains the speeches and discussion reports of the 29th Trier colloquium on the environmental and techniques law, which was dedicated to the theme ''Energy change in the industrial society''. The goal a the colloquium consisted, to work out central questions of the energy change and also to look beyond the legal field. The documented speeches deal mainly with the promotional system of the renewal-energy law and its need for reform, whereby this topic is discussed from legal, economic, and business perspective. A further main topic form questions of planning. Hereby it deals both with the regulation of the increased use of renewable energies in zoning and land-use planning and with the network expansion including public participation. Object of the discussion are also the providing of the base load by conventional power plants as well as legal questions of the compensation and load balancing in the connection of off-shore facilities.

  16. On-Shore Pipeline Emergency Repair Center; Centro de Reparos Emergenciais de Dutos Terrestres

    Energy Technology Data Exchange (ETDEWEB)

    Souza Filho, Byron Goncalves de [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil)

    2003-07-01

    After the accidents happened on years 2000 and 2001, in TRANSPETRO's operated pipelines, appeared a common conscientiousness about the necessity for the creation of a basic infrastructure for emergency and contingency pipeline repair that centralize equipment, procedures and technologies applied to pipeline maintenance. Then, it was planned the creation of the On-Shore Pipeline Emergency Center (CRE-DUT), following the model of the Off-Shore Pipelines Repair Group from PETROBRAS/EP, (Exploration and Production) and other similar centers of pipeline transport companies worldwide (Canada, Colombia, Mexico, Argentina). The CRE-DUT has the Mission of offering contingency; emergency and specials on-shore pipelines repair services, with safety, quality and at the less possible time, seeking for the leadership on applying new technologies and the excellency in repair activities. (author)

  17. Numerical and Experimental Results of a Passive Free Yawing Downwind Wind Turbine

    DEFF Research Database (Denmark)

    Verelst, David Robert; Van Wingerden, Jan-Willem

    The background of this PhD study concerns a medium sized 3 bladed wind turbine in a free yawing and downwind configuration. Largely funded by an EU Marie-Curie IAPP grant, the project was jointly setup by the renewable energy consultant 3E, DTU Wind Energy and the TU Delft. The 3 bladed free yawing...... downwind concept is pursued in an attempt to increase the robustness of a wind turbine by eliminating the traditionally actively controlled, and sometimes failure prone yawing mechanism. Under certain conditions, such as for remote (off shore) and off grid applications, a decreased failure rate can...... increase the economical competitiveness significantly compared to more traditional power supplies. This work presents aeroelastic analysis and results of a wind tunnel test campaign for the 3 bladed free yawing downwind concept. The investigated topics concern free yawing stability and how it is affected...

  18. Effects of copepod size on fish growth: A model based on data for North Sea sandeel

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Jørgensen, C.; Fiksen, Ø.

    2015-01-01

    In productive marine off-shore ecosystems, the flow of energy from zooplankton to large predators is channeled through a few species of short-lived, highly abundant schooling planktivorous fish. There are indications that these species respond to qualitative and phenological changes...... in the zooplankton. If so, the climate-induced alterations of the local copepod communities that we see in temperate and arctic regions may influence the energy flux in marine food chains. In order to investigate how different processes contribute to the relationship between copepod size and fish growth, we merged 2...... was the most important factor, followed by handling time limitation and prey energy content. These limitations became stronger with increasing fish length, showing that copepod size and energy content have a strong effect on the specific growth potential of these fish...

  19. Analysis of Grain Size Distribution and Hydraulic Conductivity for a Variety of Sediment Types with Application to Wadi Sediments

    KAUST Repository

    Rosas Aguilar, Jorge

    2013-05-01

    Grain size distribution, porosity, and hydraulic conductivity from over 400 unlithified sediment samples were analized. The measured hydraulic conductivity values were then compared to values calculated using 20 different empirical equations commonly used to estimate hydraulic conductivity from grain size analyses. It was found that most of the hydraulic conductivity values estimated from the empirical equations correlated very poorly to the measured hydraulic conductivity values. Modifications of the empirical equations, including changes to special coefficients and statistical off sets, were made to produce modified equations that considerably improve the hydraulic conductivity estimates from grain size data for beach, dune, off shore marine, and wadi sediments. Expected hydraulic conductivity estimation errors were reduced. Correction factors were proposed for wadi sediments, taking mud percentage and the standard deviation (in phi units) into account.

  20. 12th International Conference of Dynamical Systems-Theory and Applications

    CERN Document Server

    Applied Non-Linear Dynamical Systems

    2014-01-01

    The book is a collection of contributions devoted to analytical, numerical and experimental techniques of dynamical systems, presented at the International Conference on Dynamical Systems: Theory and Applications, held in Łódź, Poland on December 2-5, 2013. The studies give deep insight into both the theory and applications of non-linear dynamical systems, emphasizing directions for future research. Topics covered include: constrained motion of mechanical systems and tracking control; diversities in the inverse dynamics; singularly perturbed ODEs with periodic coefficients; asymptotic solutions to the problem of vortex structure around a cylinder; investigation of the regular and chaotic dynamics; rare phenomena and chaos in power converters; non-holonomic constraints in wheeled robots; exotic bifurcations in non-smooth systems; micro-chaos; energy exchange of coupled oscillators; HIV dynamics; homogenous transformations with applications to off-shore slender structures; novel approaches to a qualitative s...

  1. Economic instruments in the service of climate

    International Nuclear Information System (INIS)

    Buba, Johanne; Ben-Jelloul, Mahdi; Schaff, Clement

    2011-11-01

    Within the perspective of new international agreements after those signed in Kyoto (1997), in Cancun (2010) and in Durban (2011), this document recalls the frameworks defined during these summits, outline the challenges regarding climate change and makes five propositions. The first one is to prepare the conditions for and experimentation of a CO 2 emission trading scheme between the European market and the one of other countries. The second one is to re-establish competitive neutrality in the most emitting industrial sectors which are the most exposed to international competition and more easily subjected to off-shoring practices. The third one is the possibility for a country to reduce its greenhouse gas emissions while financing reductions in other countries. The fourth one is to harmonise emission measurement and accounting standards. The last one is to create a European institute for research and education on economic mechanisms of struggle against global warming

  2. High frequent modelling of a modular multilevel converter using passive components

    DEFF Research Database (Denmark)

    El-Khatib, Walid Ziad; Holbøll, Joachim; Rasmussen, Tonny Wederberg

    2013-01-01

    ). This means that a high frequency model of the converter has to be designed, which gives a better overview of the impact of high frequency transients etc. The functionality of the model is demonstrated by application to grid connections of off-shore wind power plants. Grid connection of an offshore wind power...... wind power plant employing HVDC. In the present study, a back to back HVDC transmission system is designed in PSCAD/EMTDC. Simulations and results showing the importance of high frequent modeling are presented....... plant using HVDC fundamentally changes the electrical environment for the power plant. Detailed knowledge and understanding of the characteristics and behavior of all relevant power system components under all conditions, including under transients, are required in order to develop reliable offshore...

  3. Low-frequency wave propagation in an elastic plate loaded by a two-layer fluid

    DEFF Research Database (Denmark)

    Indeitsev, Dmitrij; Sorokin, Sergey

    2012-01-01

    concern is propagation of low-frequency waves in such a coupled waveguide. In the present paper, we assume that an inhomogeneous fluid may be modelled as two homogeneous, inviscid and incompressible layers with slightly different densities. The lighter layer of fresh water lies on top of the heavier layer......In several technical applications, for example, in the Arctic off-shore oil industry, it is necessary to predict waveguide properties of floating elastic plates in contact with a relatively thin layer of water, which has a non-uniform density distribution across its depth. The issue of particular...... formulation, such as depths of the layers, stiffness and inertia of the plate, are assessed in several frequency ranges. Dispersion diagrams obtained from approximate dispersion relations are compared with their exact counterparts....

  4. Structural Reliability Methods for Wind Power Converter System Component Reliability Assessment

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2012-01-01

    Wind power converter systems are essential subsystems in both off-shore and on-shore wind turbines. It is the main interface between generator and grid connection. This system is affected by numerous stresses where the main contributors might be defined as vibration and temperature loadings....... The temperature variations induce time-varying stresses and thereby fatigue loads. A probabilistic model is used to model fatigue failure for an electrical component in the power converter system. This model is based on a linear damage accumulation and physics of failure approaches, where a failure criterion...... is defined by the threshold model. The attention is focused on crack propagation in solder joints of electrical components due to the temperature loadings. Structural Reliability approaches are used to incorporate model, physical and statistical uncertainties. Reliability estimation by means of structural...

  5. Study on seismic stability of seawall in man-made island. Pt. 1. Shaking table tests on dynamic behavior of seawall constructed on the bedrock

    International Nuclear Information System (INIS)

    Tochigi, Hitoshi; Kanatani, Mamoru; Kawai, Tadashi

    1999-01-01

    In the development of siting technology for off-shore nuclear power plants on man-made island, assessing the stability of seawall which ensures the safety of backfill ground against ocean waves and earthquakes is indispensable. In assessing seismic stability of seawall, evaluation of dynamic nonlinear behavior like sliding and settlement is an important factor. For this purpose, shake-table tests of seawall model have been carried out. By the experiments in the case of well compacted backfill ground, it is indicated that dynamic failure of caisson type seawall constructed on the strong seabed ground is mainly induced by the sliding of caisson toward the sea and followed by the settlement of backfill ground. And as the influence of armour embankment on the seismic stability of seawall, we experimentally showed that the sliding displacement of caisson during earthquake is reduced by the lateral pressure of armour units and armour embankment works effectively to rise up earthquake resistance capability of seawall. (author)

  6. Study on seismic stability of seawall in man-made island. Pt. 3. Development of evaluation method for seismic stability of seawall considering dynamic interaction of armour embankment and caisson

    International Nuclear Information System (INIS)

    Tochigi, Hitoshi; Kanatani, Mamoru; Kawai, Tadashi

    1999-01-01

    In the development of siting technology for off-shore nuclear power plants on man-made island, assessing the stability of seawall which ensure the safety of backfill ground against ocean waves and earthquakes is indispensable. Concerning the seismic stability of seawall, it is indicated that the evaluation of the influence of lateral pressure of armour embankment acting on the caisson wall is an important factor. We proposed modeling method of discontinuity such as armour unit by distinct element method (DEM) and combined them with caisson type seawall model idealized by FEM. To show the validity of this DEM-FEM hybrid analysis method, the numerical simulation for the shaking table tests was conducted. For the two kinds of seawall model with armour embankment and without the one, the lateral displacement of the seawall induced by sliding of caisson is successfully reproduced and accuracy of above mentioned numerical procedure is confirmed. (author)

  7. Effects of organic enrichment on macrofauna community structure: an experimental approach

    Directory of Open Access Journals (Sweden)

    Rodrigo Riera

    2013-12-01

    Full Text Available The determination of the resilience of benthic assemblages is a capital issue for the off-shore aquaculture industry in its attempts to minimize environmental disturbances. Experimental studies are an important tool for the establishment of thresholds for macrofaunal assemblages inhabiting sandy seabeds. An experiment was conducted with three treatments (Control, 1x and 3x,in which organic load (fish pellets was added (1x (10 g of fish pellets and 3x (30 g. A reduction in abundance of individuals and species richness was found as between the control and organic-enriched treatments. Significant changes in assemblage structure were also found, mainly due to the decrease of the sensitive tanaid Apseudes talpa in organically-enriched treatments. AMBI and M-AMBI indices were calculated and a decrease of ecological status was observed in treatment 3x.

  8. Computational mechanics of nonlinear response of shells

    International Nuclear Information System (INIS)

    Kraetzig, W.B.; Onate, E.

    1990-01-01

    Shell structures and their components are utilized in a wide spectrum of engineering fields reaching from space and aircraft structures, pipes and pressure vessels over liquid storage tanks, off-shore installations, cooling towers and domes, to bodyworks of motor vehicles. Of continuously increasing importance is their nonlinear behavior, in which large deformations and large rotations are involved as well as nonlinear material properties. The book starts with a survey about nonlinear shell theories from the rigorous point of view of continuum mechanics, this starting point being unavoidable for modern computational concepts. There follows a series of papers on nonlinear, especially unstable shell responses, which draw computational connections to well established tools in the field of static and dynamic stability of systems. Several papers are then concerned with new finite element derivations for nonlinear shell problems, and finally a series of authors contribute to specific applications opening a small window of the above mentioned wide spectrum. (orig./HP) With 159 figs

  9. Extreme winds and waves for offshore turbines: Coupling atmosphere and wave modeling for design and operation in coastal zones

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo; Bolanos, Rodolfo; Du, Jianting

    modeling for oshore wind farms. This modeling system consists of the atmospheric Weather Research and Forecasting (WRF) model, the wave model SWAN and an interface the Wave Boundary Layer Model WBLM, within the framework of coupled-ocean-atmosphere-wave-sediment transport modeling system COAWST...... (Hereinafter the WRF-WBLM-SWAN model). WBLM is implemented in SWAN, and it calculates stress and kinetic energy budgets in the lowest atmospheric layer where the wave-induced stress is introduced to the atmospheric modeling. WBLM ensures consistent calculation of stress for both the atmospheric and wave......, which can aect the choice of the off-shore wind turbine type. X-WiWa examined various methodologies for wave modeling. The offline coupling system using atmospheric data such as WRF or global reanalysis wind field to the MIKE 21 SW model has been improved with considerations of stability, air density...

  10. Incentives and barriers for wind power expansion and system integration in Denmark

    DEFF Research Database (Denmark)

    Hvelplund, Frede; Ostergaard, Poul Alberg; Meyer, Niels I

    2017-01-01

    In Denmark expansion of on-shore, near-shore and off-shore wind power is planned to increase the wind power share to 50% of electricity consumption by 2020. In this situation a continuation of past policies will not suffice, and a dual-track incentive system that both establishes incentives...... for investing in wind power and integration infrastructure with integration between the electricity, heating and transportation sectors, is required. The current Danish taxation system discourages electricity use and works against this integration. Likewise, the current day-ahead electricity spot market...... is not appropriate for a high-wind future as wind reduces price levels, but integration across sectors can partly assist in increasing demand and prices. The European Emission Trading System does not suffice in providing a level playing field for wind power and thus needs a revision. Another barrier for on...

  11. Decommissioning of offshore oil and gas installations

    International Nuclear Information System (INIS)

    Day, M.D.; Marks, M.H.

    1997-01-01

    A task facing the offshore oil and gas industry is the removal of about 7000 platforms. In this chapter, the legal framework for offshore platform decommissioning is first discussed. The various phases of abandonment are then described. The first and most critical of these is the planning phase which should be initiated years in advance when depletion plans for a field are recommended. Seven discrete activities are identified in the abandonment process itself and briefly discussed. These are: the permanent plugging and abandonment of non-productive well bores; pre-abandonment surveys and data gathering to gain knowledge about the platform and its condition; decommissioning; structure removal; disposal, recycle or reuse of platform components on or off shore; site clearance. (13 figures; 13 references) (UK)

  12. Rethinking Lean Service

    Science.gov (United States)

    Seddon, John; O'Donovan, Brendan; Zokaei, Keivan

    Ever since Levitt's influential Harvard Business Review article 'Production-Line Approach to Service' was published in 1972, it has been common for services to be treated like production lines in both the academic literature and more widely in management practice. The belief that achieving economies of scale will reduce unit costs is a common feature of management decision-making. As technological advancement has produced ever more sophisticated IT and telephony, it has become increasingly easier for firms to standardise and off-shore services. The development of the 'lean' literature has only helped to emphasise the same underlying management assumptions: by managing cost and workers' activity, organisational performance is expected to improve. This chapter argues that through misinterpretation of the core paradigm 'lean' has become subsumed into the 'business as usual' of conventional service management. As a result, 'lean' has become synonymous with 'process efficiency' and the opportunity for significant performance improvement - as exemplified by Toyota - has been missed.

  13. Evaluating commercial marine emissions and their role in air quality policy using observations and the CMAQ model

    Science.gov (United States)

    Ring, Allison M.; Canty, Timothy P.; Anderson, Daniel C.; Vinciguerra, Timothy P.; He, Hao; Goldberg, Daniel L.; Ehrman, Sheryl H.; Dickerson, Russell R.; Salawitch, Ross J.

    2018-01-01

    We investigate the representation of emissions from the largest (Class 3) commercial marine vessels (c3 Marine) within the Community Multiscale Air Quality (CMAQ) model. In present emissions inventories developed by the United States Environmental Protection Agency (EPA), c3 Marine emissions are divided into off-shore and near-shore files. Off-shore c3 Marine emissions are vertically distributed within the atmospheric column, reflecting stack-height and plume rise. Near-shore c3 Marine emissions, located close to the US shoreline, are erroneously assumed to occur only at the surface. We adjust the near-shore c3 Marine emissions inventory by vertically distributing these emissions to be consistent with the off-shore c3 Marine inventory. Additionally, we remove near-shore c3 Marine emissions that overlap with off-shore c3 Marine emissions within the EPA files. The CMAQ model generally overestimates surface ozone (O3) compared to Air Quality System (AQS) site observations, with the largest discrepancies occurring near coastal waterways. We compare modeled O3 from two CMAQ simulations for June, July, and August (JJA) 2011 to surface O3 observations from AQS sites to examine the efficacy of the c3 Marine emissions improvements. Model results at AQS sites show average maximum 8-hr surface O3 decreases up to ∼6.5 ppb along the Chesapeake Bay, and increases ∼3-4 ppb around Long Island Sound, when the adjusted c3 Marine emissions are used. Along with the c3 Marine emissions adjustments, we reduce on-road mobile NOX emissions by 50%, motivated by work from Anderson et al. 2014, and reduce the lifetime of the alkyl nitrate species group from ∼10 days to ∼1 day based on work by Canty et al. 2015, to develop the ;c3 Science; model scenario. Simulations with these adjustments further improve model representation of the atmosphere. We calculate the ratio of column formaldehyde (HCHO) and tropospheric column nitrogen dioxide (NO2) using observations from the Ozone

  14. Arsenal of democracy in the face of change: Precision Guided Munitions (PGMs), their evolution and some economic considerations, Working Paper No. 4

    Energy Technology Data Exchange (ETDEWEB)

    Chester, C.V.

    1990-08-01

    A brief study was made of some of the forces driving the move to Precision Guided Munitions (PGMs), including the quest for military effectiveness, combat experience, and logistic compression. PGMs cost from a few hundred to a few thousand dollars per Kg but are tens to hundreds of times more effective than conventional munitions. A year's peacetime plateau production of each US PGM can be carried by a few C-5 aircraft. Surge quantities of PGMs are within US airlift capabilities, taking some of the risk out of off-shore procurement. The improving capability of antiaircraft PGMs and the escalating cost of combat aircraft (50 to 100-fold in constant dollars since WW II) may bring into question the economic viability of manned attack aircraft. The same may be true to a slightly lesser degree for heavy armored vehicles. 14 refs., 5 tabs.

  15. Improvement of detection of stress corrosion cracks with ultrasonic phased array probes

    International Nuclear Information System (INIS)

    Wustenberg, H.; Mohrle, W.; Wegner, W.; Schenk, G.; Erhard, A.

    1986-01-01

    Probes with linear arrays can be used for the detection of stress corrosion cracks especially if the variability of the sound field is used to change the skewing angle of angle beam probes. The phased array concept can be used to produce a variable skewing angle or a variable angle of incidence depending on the orientation of the linear array on the wedge. This helps to adapt the direction of the ultrasonic beam to probable crack orientations. It has been demonstrated with artificial reflectors as well as with corrosion cracks, that the detection of misoriented cracks can be improved by this approach. The experiences gained during the investigations are encouraging the application of phased array probes for stress corrosion phenomena close to the heat effected zone of welds. Probes with variable skewing angles may find some interesting applications on welds in tubular structures e.g., at off shore constructions and on some difficult geometries within the primary circuit of nuclear power plants

  16. Modern high strength QT, TM and duplex-stainless steels

    International Nuclear Information System (INIS)

    Bocquet, P.; Luxenburger, G.; Porter, D.; Ericsson, C.

    2003-01-01

    Pressure vessels are commonly manufactured with normalised steel grades with a yield strength up to 355 MPa or with austenitic stainless steels when corrosion as to be considered. From three decades, modern steels with higher mechanical properties - up to yield strength of 960 Mpa - are available and largely used for other applications where weight saving is of major importance as per off-shore, bridges, cranes, shipbuilding, line pipes.. The paper presents these modern steel's families - TMCP (Thermo Mechanically Controlled Process), QT (Quenched and Tempered) and Duplex (austeno-ferritic) stainless - in comparison with the normalised and austenitic steel grades. The following aspects are presented: the main mechanical properties (tensile and Charpy) as per the requirements of the standards for pressure equipment; some examples of use of these modern steels in the industry are given; the limitations of the forming conditions are considered; the weldability aspects and welds properties are developed; the interest of the PWHT (Post Weld Heat Treatment) is discussed. (orig.)

  17. Experience of cumulative effects assessment in the UK

    Directory of Open Access Journals (Sweden)

    Piper Jake

    2004-01-01

    Full Text Available Cumulative effects assessment (CEA is a development of environmental impact assessment which attempts to take into account the wider picture of what impacts may affect the environment as a result of either multiple or linear projects, or development plans. CEA is seen as a further valuable tool in promoting sustainable development. The broader canvas upon which the assessment is made leads to a suite of issues such as complexity in methods and assessment of significance, the desirability of co-operation between developers and other parties, new ways of addressing mitigation and monitoring. After outlining the legislative position and the process of CEA, this paper looks at three cases studies in the UK where cumulative assessment has been carried out - the cases concern wind farms, major infrastructure and off-shore developments.

  18. Power applications for superconducting cables in Denmark

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Østergaard, Jacob; Olsen, S. Krüger

    1999-01-01

    In Denmark a growing concern for environmental protection has lead to wishes that the open country is kept free of overhead lines as far as possible. New lines under 100 kV and existing 60/50 kV lines should be established as underground cables. Superconducting cables represent an interesting...... in cases such as transmission of energy into cities and through areas of special interest. The planned large groups of windmills in Denmark generating up to 2000 MVA or more both on dry land and off-shore will be an obvious case for the application of superconducting AC or DC cables. These opportunities...... can be combined with other new technologies such as HVDC light transmission using isolated gate bipolar transistors (IGBTs). The network needed in a system with a substantial wind power generation has to be very strong in order to handle energy fluctuations. Such a network will be possible...

  19. Timing matters

    DEFF Research Database (Denmark)

    Kothari, Ninad B.; Wohlgemuth, Melville J.; Hulgard, Katrine

    2014-01-01

    To successfully negotiate a cluttered environment, an echolocating bat must control the timing of motor behaviors in response to dynamic sensory information. Here we detail the big brown bat's adaptive temporal control over sonar call production for tracking prey, moving predictably or unpredicta...

  20. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/reso/010/02/0020-0032. Keywords. Discovery of echolocation; Donald Griffin; bats; magic well. Author Affiliations. H Raghuram1 G Marimuthu1. Department of Animal Behaviour and Physiology Schpol of Biological Sciences Madurai Kamaraj University Madurai 625 021, ...

  1. Refresher Course on Animal Behaviour

    Indian Academy of Sciences (India)

    an insect, echolocation and foraging behaviour of bats, and human circadian rhythms. The Course Director will be Dr G Marimuthu and Dr Sripathi Kandula will be the Course. Coordinator. Teachers who wish to participate in this Refresher Course should submit their brief curriculum vitae (including name, date of birth, sex, ...

  2. Accounting for false-positive acoustic detections of bats using occupancy models

    Science.gov (United States)

    Clement, Matthew J.; Rodhouse, Thomas J.; Ormsbee, Patricia C.; Szewczak, Joseph M.; Nichols, James D.

    2014-01-01

    1. Acoustic surveys have become a common survey method for bats and other vocal taxa. Previous work shows that bat echolocation may be misidentified, but common analytic methods, such as occupancy models, assume that misidentifications do not occur. Unless rare, such misidentifications could lead to incorrect inferences with significant management implications.

  3. Hearing and evasive behavior in the greater wax moth, Galleria mellonella (Pyralidae)

    DEFF Research Database (Denmark)

    Skals, Niels; Surlykke, Annemarie

    2000-01-01

    Greater wax moths (Galleria mellonella L., Pyraloidea) use ultrasound sensitive ears to detect clicking conspeci®cs and echolocating bats. Pyralid ears have four sensory cells, A1±4. The audiogram of G. mellonella has best frequency at 60 kHz with a threshold around 47 dB sound pressure level. A1...

  4. Flight activity and habitat preference of bats in a karstic area, as revealed by bat detectors

    Czech Academy of Sciences Publication Activity Database

    Zukal, Jan; Řehák, Z.

    2006-01-01

    Roč. 55, č. 3 (2006), s. 273-281 ISSN 0139-7893 Institutional research plan: CEZ:AV0Z60930519 Keywords : Moravian Karst * echolocation calls * bat community * detectoring Subject RIV: EG - Zoology Impact factor: 0.529, year: 2006 http://www.ivb.cz/folia/55/3/273-281.pdf

  5. The Microchip Optera Project

    National Research Council Canada - National Science Library

    Moss, Cynthia; Horiuchi, Timothy K

    2006-01-01

    .... The long-term goal of this project is to build a tiny, low-power, neuromorphic VLSI-based model of an FM bat echolocation system that can be demonstrated in an aerial target capture task using a flying vehicle...

  6. The simple ears of noctuoid moths are tuned to the calls of their sympatric bat community

    DEFF Research Database (Denmark)

    Ter Hofstede, Hannah M; Goerlitz, Holger R; Ratcliffe, John M

    2013-01-01

    Insects with bat-detecting ears are ideal animals for investigating sensory system adaptations to predator cues. Noctuid moths have two auditory receptors (A1 and A2) sensitive to the ultrasonic echolocation calls of insectivorous bats. Larger moths are detected at greater distances by bats than ...

  7. Functional convergence in bat and toothed whale biosonars

    DEFF Research Database (Denmark)

    Madsen, P T; Surlykke, A

    2013-01-01

    Echolocating bats and toothed whales hunt and navigate by emission of sound pulses and analysis of returning echoes to form a self-generated auditory scene. Here, we demonstrate a striking functional convergence in the way these two groups of mammals independently evolved the capability to sense ...

  8. Calculation of Head Related Transfer Functions of bats using the Boundary Element Method

    DEFF Research Database (Denmark)

    Juhl, Peter Møller; Cutanda Henriquez, Vicente; Vanderelst, Dieter

    2009-01-01

    Overskrift: ChiRoPing (Chiroptera, Robots, and Sonar) is an EU-funded research project aimed at understanding how bats use their echolocation perception ability and apply this knowledge to the design of new robotic senses. Four species of bats are selected for the study and models of their heads...

  9. Clicking in a killer whale habitat: narrow-band, high-frequency biosonar clicks of harbour porpoise (Phocoena phocoena and Dall's porpoise (Phocoenoides dalli.

    Directory of Open Access Journals (Sweden)

    Line A Kyhn

    Full Text Available Odontocetes produce a range of different echolocation clicks but four groups in different families have converged on producing the same stereotyped narrow band high frequency (NBHF click. In microchiropteran bats, sympatric species have evolved the use of different acoustic niches and subtly different echolocation signals to avoid competition among species. In this study, we examined whether similar adaptations are at play among sympatric porpoise species that use NBHF echolocation clicks. We used a six-element hydrophone array to record harbour and Dall's porpoises in British Columbia (BC, Canada, and harbour porpoises in Denmark. The click source properties of all porpoise groups were remarkably similar and had an average directivity index of 25 dB. Yet there was a small, but consistent and significant 4 kHz difference in centroid frequency between sympatric Dall's (137±3 kHz and Canadian harbour porpoises (141±2 kHz. Danish harbour porpoise clicks (136±3 kHz were more similar to Dall's porpoise than to their conspecifics in Canada. We suggest that the spectral differences in echolocation clicks between the sympatric porpoises are consistent with evolution of a prezygotic isolating barrier (i.e., character displacement to avoid hybridization of sympatric species. In practical terms, these spectral differences have immediate application to passive acoustic monitoring.

  10. Floral acoustics : conspicuous echoes of a dish-shaped leaf attract bat pollinators

    NARCIS (Netherlands)

    Simon, Ralph; Holderied, Marc W; Koch, Corinna U; von Helversen, Otto

    2011-01-01

    The visual splendor of many diurnal flowers serves to attract visually guided pollinators such as bees and birds, but it remains to be seen whether bat-pollinated flowers have evolved analogous echo-acoustic signals to lure their echolocating pollinators. Here, we demonstrate how an unusual

  11. Hearing diversity in moths confronting a neotropical bat assemblage.

    Science.gov (United States)

    Cobo-Cuan, Ariadna; Kössl, Manfred; Mora, Emanuel C

    2017-09-01

    The tympanal ear is an evolutionary acquisition which helps moths survive predation from bats. The greater diversity of bats and echolocation strategies in the Neotropics compared with temperate zones would be expected to impose different sensory requirements on the neotropical moths. However, even given some variability among moth assemblages, the frequencies of best hearing of moths from different climate zones studied to date have been roughly the same: between 20 and 60 kHz. We have analyzed the auditory characteristics of tympanate moths from Cuba, a neotropical island with high levels of bat diversity and a high incidence of echolocation frequencies above those commonly at the upper limit of moths' hearing sensitivity. Moths of the superfamilies Noctuoidea, Geometroidea and Pyraloidea were examined. Audiograms were determined by non-invasively measuring distortion-product otoacoustic emissions. We also quantified the frequency spectrum of the echolocation sounds to which this moth community is exposed. The hearing ranges of moths in our study showed best frequencies between 36 and 94 kHz. High sensitivity to frequencies above 50 kHz suggests that the auditory sensitivity of moths is suited to the sounds used by sympatric echolocating bat fauna. Biodiversity characterizes predators and prey in the Neotropics, but the bat-moth acoustic interaction keeps spectrally matched.

  12. Neural network modeling of a dolphin's sonar discrimination capabilities

    DEFF Research Database (Denmark)

    Andersen, Lars Nonboe; René Rasmussen, A; Au, WWL

    1994-01-01

    The capability of an echo-locating dolphin to discriminate differences in the wall thickness of cylinders was previously modeled by a counterpropagation neural network using only spectral information of the echoes [W. W. L. Au, J. Acoust. Soc. Am. 95, 2728–2735 (1994)]. In this study, both time a...

  13. How the bat got its buzz

    DEFF Research Database (Denmark)

    Ratcliffe, John M; Elemans, Coen P H; Jakobsen, Lasse

    2013-01-01

    Since the discovery of echolocation in bats, the final phase of an attack on a flying insect, the 'terminal buzz', has proved enigmatic. During the buzz, bats increase information update rates by producing vocalizations up to 220 times s(-1). The buzz's ubiquity in hawking and trawling bats impli...

  14. NED-DARWINIAN ACCOUNTS OF mE EVOLUTION OF LANGUAGE ...

    African Journals Online (AJOL)

    echo-location or stereopsis, and that the only way to explain the origin of such abilities is ...... explanation. They force me into a position from which I can only criticize ..... The emergence of homo loquens and the laws of physics. Behavioral.

  15. Moth hearing and sound communication

    DEFF Research Database (Denmark)

    Nakano, Ryo; Takanashi, Takuma; Surlykke, Annemarie

    2015-01-01

    Active echolocation enables bats to orient and hunt the night sky for insects. As a counter-measure against the severe predation pressure many nocturnal insects have evolved ears sensitive to ultrasonic bat calls. In moths bat-detection was the principal purpose of hearing, as evidenced by compar......Active echolocation enables bats to orient and hunt the night sky for insects. As a counter-measure against the severe predation pressure many nocturnal insects have evolved ears sensitive to ultrasonic bat calls. In moths bat-detection was the principal purpose of hearing, as evidenced...... by comparable hearing physiology with best sensitivity in the bat echolocation range, 20–60 kHz, across moths in spite of diverse ear morphology. Some eared moths subsequently developed sound-producing organs to warn/startle/jam attacking bats and/or to communicate intraspecifically with sound. Not only...... the sounds for interaction with bats, but also mating signals are within the frequency range where bats echolocate, indicating that sound communication developed after hearing by “sensory exploitation”. Recent findings on moth sound communication reveal that close-range (~ a few cm) communication with low...

  16. Cooperative control system of the floating cranes for the dual lifting

    Directory of Open Access Journals (Sweden)

    Mihee Nam

    2018-01-01

    Full Text Available This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes are well-coordinated to add up the lift capabilities of both cranes without any loss such that virtually a single crane is lifting, maneuvering and unloading. Two main constraints for the dual lifting are as follows: First, two barges of floating cranes should be constrained as a rigid body not to cause a relative motion between two barges and main hooks of the two cranes should be controlled as main hooks of a single crane. In order words, it is necessary to develop the cooperative control of two floating cranes in order to sustain a center of gravity of the module and minimize the tilting angle during the lifting and unloading by the two floating cranes. Two floating cranes are handled as a master-slave system. The master crane is able to gather information about all working conditions and make a decision to control the individual hook speed, which communicates the slave crane by TCP/IP. The developed control system has been embedded in the real floating crane systems and the dual lifting has been demonstrated five times at SHI shipyard in 2015. The moving angles of the lifting module are analyzed and verified to be suitable for hoisting control. It is verified that the dual lifting can be applied for many heavier and wider blocks and modules to shorten the construction time of ships and off-shore platforms.

  17. Western Continental Margin of India - Re-look using potential field data

    Science.gov (United States)

    Rajaram, M.; S P, A.

    2008-05-01

    The Western Continental Margin of India (WCMI) evolved as a result of rifting between India and Madagascar that took place during mid Cretaceous (~88Ma).The WCMI is equally important in terms of natural resources as well as research point of view. The major tectonic elements in the western offshore includes the Laxmi and Chagos- Laccadive ridge dividing the WCMI and the adjoining Arabian sea into two basins, Pratap Ridge, Alleppey platform etc. Different theories have been proposed for the evolution of each of these tectonic elements. In the current paper we look at geopotential data on the west coast of India and the western off-shore. The data sets utilized include Satellite derived High Resolution Free Air Gravity data over the off-shore, Bouguer data onland, Champ Satellite Magnetic data, published Marine Magnetic data collected by ONGC, NIO, ground magnetic data over west cost collected by IIG and available aeromagnetic data. From the free air gravity anomaly the structural details of the western offshore can be delineated. The Euler depths of FAG depict deep solutions associated with Pratap Ridge, Comorin Ridge, the west coast fault and the Laxmi Ridge. These may be associated with continental margin and continental fragments. From the aeromagnetic and marine magnetic data it is evident that the West Coast Fault is dissected at several places. The shallow circular feature associated with Bombay High is evident both on the FAG and the analytic signal derived from satellite Magnetic data. The crustal magnetic thickness from MF5 lithospheric model of the Champ appears to suggest that the continental crust extends up to the Chagos- Laccadive ridge. Based on the analysis of these geopotential data sets the various theories for the evolution of the WCMI will be evaluated and these results will be presented.

  18. Towards sustainable fishery management for skates in South America: The genetic population structure of Zearaja chilensis and Dipturus trachyderma (Chondrichthyes, Rajiformes in the south-east Pacific Ocean.

    Directory of Open Access Journals (Sweden)

    Carolina Vargas-Caro

    Full Text Available The longnose skates (Zearaja chilensis and Dipturus trachyderma are the main component of the elasmobranch fisheries in the south-east Pacific Ocean. Both species are considered to be a single stock by the fishery management in Chile however, little is known about the level of demographic connectivity within the fishery. In this study, we used a genetic variation (560 bp of the control region of the mitochondrial genome and ten microsatellite loci to explore population connectivity at five locations along the Chilean coast. Analysis of Z. chilensis populations revealed significant genetic structure among off-shore locations (San Antonio, Valdivia, two locations in the Chiloé Interior Sea (Puerto Montt and Aysén and Punta Arenas in southern Chile. For example, mtDNA haplotype diversity was similar across off-shore locations and Punta Arenas (h = 0.46-0.50, it was significantly different to those in the Chiloé Interior Sea (h = 0.08. These results raise concerns about the long-term survival of the species within the interior sea, as population resilience will rely almost exclusively on self-recruitment. In contrast, little evidence of genetic structure was found for D. trachyderma. Our results provide evidence for three management units for Z. chilensis, and we recommend that separate management arrangements are required for each of these units. However, there is no evidence to discriminate the extant population of Dipturus trachyderma as separate management units. The lack of genetic population subdivision for D. trachyderma appears to correspond with their higher dispersal ability and more offshore habitat preference.

  19. Electrorheology for energy production and conservation

    Science.gov (United States)

    Huang, Ke

    Recently, based on the physics of viscosity, we developed a new technology, which utilizes electric or magnetic fields to change the rheology of complex fluids to reduce the viscosity, while keeping the temperature unchanged. The method is universal and applicable to all complex fluids with suspended particles of nano-meter, submicrometer, or micrometer size. Completely different from the traditional viscosity reduction method, raising the temperature, this technology is energy-efficient, as it only requires small amount of energy to aggregate the suspended particles. In this thesis, we will first discuss this new technology in detail, both in theory and practice. Then, we will report applications of our technology to energy science research. Presently, 80% of all energy sources are liquid fuels. The viscosity of liquid fuels plays an important role in energy production and energy conservation. With an electric field, we can reduce the viscosity of asphalt-based crude oil. This is important and useful for heavy crude oil and off-shore crude oil production and transportation. Especially, since there is no practical way to raise the temperature of crude oil inside the deepwater pipelines, our technology may play a key role in future off-shore crude oil production. Electrorehology can also be used to reduce the viscosity of refinery fuels, such as diesel fuel and gasoline. When we apply this technology to fuel injection, the fuel droplets in the fuel atomization become smaller, leading to faster combustion in the engine chambers. As the fuel efficiency of internal combustion engines depends on the combustion speed and timing, the fast combustion produces much higher fuel efficiency. Therefore, adding our technology on existing engines improves the engine efficiency significantly. A theoretical model for the engine combustion, which explains how fast combustion improves the engine efficiency, is also presented in the thesis. As energy is the key to our national

  20. Considérations Concernant la Transposition dans la Législation Nationale des Stipulations de la Directive 2005/60/Ce du Parlement Européen et du Conseil, en Date du 26 Octobre 2005 Concernant la Prévention de L’utilisation du Système Financier dans le But du Blanchiment d’argent et du Financement du Terrorisme Relativement à L’obligation des Avocats de Rapporter les Transactions Suspectes de Blanchiment d’argent

    Directory of Open Access Journals (Sweden)

    Gabriela Lupsan

    2009-06-01

    Full Text Available En mars 1997, le Rapport de la Stratégie Internationale de Contrôle des Narcotiques1 a mentionné que le blanchiment d'argent est effectué par des spécialistes, qui vendent leurs services de haute qualité, leur expérience et savoir dans le mouvement des capitaux. Ces services sont offerts sur trois niveaux, à savoir:- Le premier niveau consiste en les conseils financiers, qui écrivent des livres, dirigent des séminaires concernant le bénéfice des taxes dans les centres off-shore. Ils sont dispos à offrir à tout moment des conseils spécifiques pour les personnes qui ont été convaincues que ce mouvement, en partie ou au total des biens financiers vers les centres off-shore, est bénéfique;- Le troisième niveau est formé d'avocats, comptables ou brokers qui détiennent unportefeuille de services offert tant aux clients légaux qu'aux infracteurs;- Le troisième niveau est formé de managers financiers, qui offrent des services spécialisés aux clients spécifiques, engagés en des activités infractionnelles. Le plus souvent, ils sont de connivence avec les infracteurs, dans le but de cacher et de blanchir l'argent de ces derniers.

  1. Edge waves excited by underwater landslides : scenarios in the sea of Marmara

    Science.gov (United States)

    Sinan Özeren, Mehmet; Postacioglu, Nazmi; Canlı, Umut; Gasperini, Luca

    2014-05-01

    In this work we quantify the travel distance of edge waves created by submarine landslide over slopes of finite length. Edge waves, if generated, can constitute severe coastal hazard because they can travel long distances along the shores. In the Sea of Marmara there are several submarine masses susceptible to slide in case of a big earthquake on the Main Marmara Fault and some damage scenarios might involve edge waves. The edge waves generated by landslide Tsunamis over slopes of infinite lenghts are recently studied by Sammarco and Renzi (Landslide tsunamis propagating along a plane beach, 2008, Journal of Fluid Mech.). However the infinite slope length assumption causes a perfect confinement of the waves over the coastal slope, thereby overestimating the edge wave damage. Because of this, in their work there is no alongshore length scale over which these waves can lose their energy. In the real worls, the off-shore limiting depth will be finite and the off-shore direction wave vector will not be completely complex, pointing to radiation damping of these edge waves. In this work we analytically quantify the amount of this damping and we estimate the travel distance of the edge waves along the shoreline as a function of the limiting depth. We examine some some scenarios in the north coast of the Sea of Marmara and the northern shelf to quantify the edge waves. Since the method does not require high-resolution numerical computing, it can be used to calculate the edge-wave related risk factor anywhere with submarine landslide risk.

  2. Wind power barometer

    International Nuclear Information System (INIS)

    2014-01-01

    The worldwide wind power increased by 12.4% in 2013 to reach 318.6 GW but the world market globally decreased by losing 10 GW: only 35.6 GW have been installed in 2013 which is even less than was installed in 2009. This activity contraction is mainly due to the collapse of the American market, American authorities having been late to decide to maintain federal incentives. The European wind power market also contracted in 2013 because of the lack of trust of the investors in the new energy policies of the European governments. In the rest of the world wind energy has kept on growing particularly in China and Canada. At the end of 2013 the cumulated wind power reached 117,73 GW in Europe. About 1.5 MW out of 10 MW of wind power installed in Europe in 2013 come from off-shore wind farms, United-Kingdom and Denmark being the most important players by totalling more than 70% of the off-shore wind power installed at the end of 2013. Various charts and tables give the figures of the wind power cumulated and installed in 2013 in different parts of the world: Europe, North America and Asia, the time evolution of the worldwide wind power since 1995, the wind power cumulated and installed in 2013 for the different countries of Europe and the ratio between the cumulated wind power and the country population. A table lists the main manufacturers of wind turbines and gives their turnover and number of employees at the end of 2013

  3. Compound specific radiocarbon content of lignin oxidation products from the Altamaha river and Coastal Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Culp, Randy, E-mail: rculp@uga.edu [Center for Applied Isotope Studies, University of Georgia, Athens, Georgia (United States)

    2013-01-15

    Compound-specific isotope analysis (CSIA) is a powerful tool in organic geochemistry by providing detailed information about an individual organic compound's history with regard to its source and process of formation. Most CSIA involves measurement of the stable isotope ratio of carbon ({sup 13}C/{sup 12}C) and hydrogen (D/H) following separation by gas or liquid chromatography. New applications are being developed using compound-specific radiocarbon ({sup 14}C) content for delineating age of materials, rates of decomposition and residence time in various environments. This paper details the isotopic work on specific lignin monomers derived from terrestrial plants transported and deposited within the Altamaha River, estuary and off-shore Georgia in the Atlantic Ocean. By using gas chromatographic separation and identification of selected lignin oxidation products (LOP), the harvesting of these compounds using preparative fraction collection, and measurement of their {sup 14}C content using accelerator mass spectrometry, details of the age and presence of specific biomarkers unique to a given terrestrial source are revealed. Radiocarbon ages determined from water-column particulate organic carbon and sediment LOPs indicate a range of ages from modern to well over 5,000 years for the former and latter respectively. Transport mechanisms and particle size associations on mineral grains may play a significant role in {sup 14}C distribution in estuary and near-shore coastal environments. This data indicates higher than modern {sup 14}C activities in large particle-size sediment fractions in contrast to older LOP {sup 14}C ages found associated with the same coarse grain sediments. Individual LOP ages substantiate older terrestrial materials persist in the off-shore environment even though in the presence of modern marine {sup 14}C sources.

  4. Wind-drive coastal currents in the Gulf of Tehuatepec: HF radar observations and numerical model simulations.

    Science.gov (United States)

    Velazquez, F. A.; Martinez, J. A.; Durazo, R.; Flament, P.

    2007-12-01

    Most of the studies on coastal dynamics in the Gulf of Tehuatepec (GT) have been focused on mixing processes and mesoscale eddies generated due to strong off-shore wind events, know as Nortes or Tehuanos. In order to investigate the spatial and temporal mesoscale variability of surface dynamic in the GT in February 2005, two HF Radar model WERA were deployed along the shore of Oaxaca, Mexico. The spatial coverage of radars reaches up to 120 km off-shore. The radial velocities were processed to obtain total velocity maps every hour in a regular grid of 5.5 km. space resolution. The information of surface velocity and quickscat/NCEP wind obtained during the first sample days show that exist a coastal current toward the west and, during the wind events, is accelerated and steered toward the southwest. In this same period, we find that spatial density of kinetic energy and divergence of velocity field increase during wind events while the vorticity becomes negative. When strong wind events are not present the surface circulation is weakened, mainly for the zonal component of the wind that is mostly positive (westward). These results are in agreement with the upwelling processes observed on the coast and the anticyclonic eddie generation west of the GT during Tehuanos. Images of sea surface temperature and chlorophyll concentration are also used to observe the signature of wind events near the shore. Complementary to field observations, numerical simulation using a 3D primitive equations model (POM) are used to study the wind-driven circulation in the GT. It has been commonly accepted in previous studies that the strong wind events generate mesoscale eddies. We discuss the limited effect of the wind and the interaction of the wind with a coastal current required to generate long life eddies.

  5. Compound specific radiocarbon content of lignin oxidation products from the Altamaha river and Coastal Georgia

    International Nuclear Information System (INIS)

    Culp, Randy

    2013-01-01

    Compound-specific isotope analysis (CSIA) is a powerful tool in organic geochemistry by providing detailed information about an individual organic compound’s history with regard to its source and process of formation. Most CSIA involves measurement of the stable isotope ratio of carbon ( 13 C/ 12 C) and hydrogen (D/H) following separation by gas or liquid chromatography. New applications are being developed using compound-specific radiocarbon ( 14 C) content for delineating age of materials, rates of decomposition and residence time in various environments. This paper details the isotopic work on specific lignin monomers derived from terrestrial plants transported and deposited within the Altamaha River, estuary and off-shore Georgia in the Atlantic Ocean. By using gas chromatographic separation and identification of selected lignin oxidation products (LOP), the harvesting of these compounds using preparative fraction collection, and measurement of their 14 C content using accelerator mass spectrometry, details of the age and presence of specific biomarkers unique to a given terrestrial source are revealed. Radiocarbon ages determined from water-column particulate organic carbon and sediment LOPs indicate a range of ages from modern to well over 5,000 years for the former and latter respectively. Transport mechanisms and particle size associations on mineral grains may play a significant role in 14 C distribution in estuary and near-shore coastal environments. This data indicates higher than modern 14 C activities in large particle-size sediment fractions in contrast to older LOP 14 C ages found associated with the same coarse grain sediments. Individual LOP ages substantiate older terrestrial materials persist in the off-shore environment even though in the presence of modern marine 14 C sources.

  6. Offshore wind energy storage concept for cost-of-rated-power savings

    International Nuclear Information System (INIS)

    Qin, Chao; Saunders, Gordon; Loth, Eric

    2017-01-01

    Highlights: •Investigated CAES + HPT system concept for offshore wind energy; •Validated cost model for offshore wind farm including CAPEX and OPEX items; •Quantified cost-of-rated-power savings associated with CAES + HPT concept; •Estimated savings of 21.6% with CAES + HPT for a sample $2.92 billion project. -- Abstract: The size and number of off-shore wind turbines over the next decade is expected to rapidly increase due to the high wind energy potential and the ability of such farms to provide utility-scale energy. In this future, inexpensive and efficient on-site wind energy storage can be critical to address short-time (hourly) mismatches between wind supply and energy demand. This study investigates a compressed air energy storage (CAES) and hydraulic power transmission (HPT) system concept. To assess cost impact, the NREL Cost and Scaling Model was modified to improve accuracy and robustness for offshore wind farms with large turbines. Special attention was paid to the support structure, installation, electrical interface and connections, land leasing, and operations and maintenance cost items as well as specific increased/reduced costs reductions associated with CAES + HPT systems. This cost model was validated and applied to a sample $2.92 billion project Virginia Offshore case It was found that adaption of CAES + HPT can lead to a substantial savings of 21.6% of this 20-year lifetime cost by dramatically reducing capital and operating cost of the generator and power transmission components. However, there are several additional variables that can impact the off-shore energy policy and planning for this new CAES + HPT concept. Furthermore, these cost-savings are only first-order estimates based on linear mass-cost relationships, and thus detailed engineering and economic analysis are recommended.

  7. Un simulateur de production de puits exploité en gas-lift A Production Simulator for Gas-Lift Wells

    Directory of Open Access Journals (Sweden)

    Caralp L.

    2006-11-01

    Full Text Available Le procédé d'exploitation assisté de pétrole par gas-lift " est utilisé dans les applications off-shore. Sa dynamique lente nuit à la réalisation in situ d'études de conditions d'exploitation optimales. Si l'on veut apprendre à conduire ce type de procédé ou optimiser les conditions d'exploitation sur un ensemble de puits, disposer d'un logiciel de simulation est une nécessité. Réalisé à partir des modèles de connaissance : - d'écoulement diphasique incluant le taux de gaz dans les bouchons d'huile (régime poches-bouchons et les échanges de masse entre phases; - de gisement; - de l'injection de gaz; le simulateur, qui emploie les corrélations les plus fréquemment utilisées décrivant les mélanges huile-gaz, fournit des résultats physiquement acceptables qui sont présentés. Le processus est non linéaire et asymétrique. Help oil well process by gas-liftare use in off shore application. Slow dynamic is an handicap for a study of optimal exploitation conditions. To learn to drive this process and to optimize exploitation conditions on an oil field it is necessary to set of a simulator. It is realized from knowledge models :(a two-phases flows, (b oil pool,(c gaz injection, including gas rate in oil slug (slug regime and mass exchange into phases. The simulator work with the most commonly use oil-gas mixture correlations. This results are physically reasonable. Process is non linear and asymetrical.

  8. Aural localization of silent objects by active human biosonar: neural representations of virtual echo-acoustic space.

    Science.gov (United States)

    Wallmeier, Ludwig; Kish, Daniel; Wiegrebe, Lutz; Flanagin, Virginia L

    2015-03-01

    Some blind humans have developed the remarkable ability to detect and localize objects through the auditory analysis of self-generated tongue clicks. These echolocation experts show a corresponding increase in 'visual' cortex activity when listening to echo-acoustic sounds. Echolocation in real-life settings involves multiple reflections as well as active sound production, neither of which has been systematically addressed. We developed a virtualization technique that allows participants to actively perform such biosonar tasks in virtual echo-acoustic space during magnetic resonance imaging (MRI). Tongue clicks, emitted in the MRI scanner, are picked up by a microphone, convolved in real time with the binaural impulse responses of a virtual space, and presented via headphones as virtual echoes. In this manner, we investigated the brain activity during active echo-acoustic localization tasks. Our data show that, in blind echolocation experts, activations in the calcarine cortex are dramatically enhanced when a single reflector is introduced into otherwise anechoic virtual space. A pattern-classification analysis revealed that, in the blind, calcarine cortex activation patterns could discriminate left-side from right-side reflectors. This was found in both blind experts, but the effect was significant for only one of them. In sighted controls, 'visual' cortex activations were insignificant, but activation patterns in the planum temporale were sufficient to discriminate left-side from right-side reflectors. Our data suggest that blind and echolocation-trained, sighted subjects may recruit different neural substrates for the same active-echolocation task. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  9. Monitoring effects of offshore windfarms on harbour porpoises using PODs (porpoise detectors)

    International Nuclear Information System (INIS)

    Teilmann, J.; Damsgaard Henriksen, O.; Carstensen, Jacob; Skov, H.

    2002-02-01

    The areas designated for offshore windfarms in Denmark, are all known habitats for harbour porpoises. It is possible that some of the activities involved in erection and operation of offshore windfarms will have a negative impact on the harbour porpoises in and around the windfarms. The most significant sources of these effects are thought to be the physical presence and the noise from ships and construction work as well as temporary and even permanent loss of suitable habitats near the windfarms. The noise from existing offshore windturbines has been measured and a detection distance of 20 m was calculated in the EIA study regarding the Roedsand windfarm. In order to study possible effects from the erection and operation of windfarms on harbour porpoises a number of studies were suggested as part of the EIA background study on harbour porpoises. Among these suggestions was the use of acoustic dataloggers (PODs). The POD is recording click sounds of short duration. It is programmable and can be set to specifically record the echolocation signals that harbour porpoises uses for orientation and foraging. This method will potentially give data on harbour porpoise activity in a specific area on a diurnal and year-round basis. The construction work will take place over several months and since there is no available information on the seasonal sensitivity of porpoises to disturbance, the data necessary to detect and evaluate the effect of the windfarm would need to cover all seasons. No other method is feasible to provide data on the presence of harbour porpoises year round in a particular area. However, this method has its limitations in that only porpoises echolocating are recorded. No data exists on the seasonal, diurnal and area specific use of echolocation but since echolocation is believed to be the primary sense for porpoises we expect that porpoises used their echolocation most of the time and that it is correlated to the density of porpoises. However, the actual

  10. Monitoring effects of offshore windfarms on harbour porpoises using PODs (porpoise detectors)

    Energy Technology Data Exchange (ETDEWEB)

    Teilmann, J.; Damsgaard Henriksen, O. [National Environmental Res. Inst., Dept. of Arctic Enviroment, Roskilde (Denmark); Carstensen, Jacob [National Environmental Res. Lab., Dept. of Marine Ecology, Roskilde (Denmark); Skov, H. [Ornis Consult A/S, Copenhagen (Denmark)

    2002-02-15

    The areas designated for offshore windfarms in Denmark, are all known habitats for harbour porpoises. It is possible that some of the activities involved in erection and operation of offshore windfarms will have a negative impact on the harbour porpoises in and around the windfarms. The most significant sources of these effects are thought to be the physical presence and the noise from ships and construction work as well as temporary and even permanent loss of suitable habitats near the windfarms. The noise from existing offshore windturbines has been measured and a detection distance of 20 m was calculated in the EIA study regarding the Roedsand windfarm. In order to study possible effects from the erection and operation of windfarms on harbour porpoises a number of studies were suggested as part of the EIA background study on harbour porpoises. Among these suggestions was the use of acoustic dataloggers (PODs). The POD is recording click sounds of short duration. It is programmable and can be set to specifically record the echolocation signals that harbour porpoises uses for orientation and foraging. This method will potentially give data on harbour porpoise activity in a specific area on a diurnal and year-round basis. The construction work will take place over several months and since there is no available information on the seasonal sensitivity of porpoises to disturbance, the data necessary to detect and evaluate the effect of the windfarm would need to cover all seasons. No other method is feasible to provide data on the presence of harbour porpoises year round in a particular area. However, this method has its limitations in that only porpoises echolocating are recorded. No data exists on the seasonal, diurnal and area specific use of echolocation but since echolocation is believed to be the primary sense for porpoises we expect that porpoises used their echolocation most of the time and that it is correlated to the density of porpoises. However, the actual

  11. Bats coordinate sonar and flight behavior as they forage in open and cluttered environments

    DEFF Research Database (Denmark)

    Falk, Benjamin; Jakobsen, Lasse; Surlykke, Annemarie

    2014-01-01

    Echolocating bats use active sensing as they emit sounds and listen to the returning echoes to probe their environment for navigation, obstacle avoidance and pursuit of prey. The sensing behavior of bats includes the planning of 3D spatial trajectory paths, which are guided by echo information....... The temporal patterning of sonar sound groups was related to path planning around obstacles in the forest. Together, these results contribute to our understanding of how bats coordinate echolocation and flight behavior to represent and navigate their environment........ In this study, we examined the relationship between active sonar sampling and flight motor output as bats changed environments from open space to an artificial forest in a laboratory flight room. Using high-speed video and audio recordings, we reconstructed and analyzed 3D flight trajectories, sonar beam aim...

  12. Application of Density Estimation Methods to Datasets Collected From a Glider

    Science.gov (United States)

    2015-09-30

    2832. PUBLICATIONS Küsel, E.T., Siderius, M., and Mellinger, D.K., “Single-sensor, cue- counting population density estimation: Average ...contained echolocation clicks of sperm whales (Physeter macrocephalus). This species is also known to occur in the Gulf of Mexico where data is...Because such approach considers the entire click bandwidth, the average probability of detection of thousands of click realizations, and hence the

  13. The furrows of Rhinolophidae revisited.

    Science.gov (United States)

    Vanderelst, Dieter; Jonas, Reijniers; Herbert, Peremans

    2012-05-07

    Rhinolophidae, a family of echolocating bats, feature very baroque noseleaves that are assumed to shape their emission beam. Zhuang & Muller (Zhuang & Muller 2006 Phys. Rev. Lett. 97, 218701 (doi:10.1103/PhysRevLett.97.218701); Zhuang & Muller 2007 Phys. Rev. E Stat. Nonlin. Soft Matter Phys. 76(Pt. 1), 051902 (doi:10.1103/PhysRevE.76.051902)) have proposed, based on finite element simulations, that the furrows present in the noseleaves of these bats act as resonance cavities. Using Rhinolophus rouxi as a model species, they reported that a resonance phenomenon causes the main beam to be elongated at a particular narrow frequency range. Virtually filling the furrows reduced the extent of the main lobe. However, the results of Zhuang & Muller are difficult to reconcile with the ecological background of R. rouxi. In this report, we replicate the study of Zhuang & Muller, and extend it in important ways: (i) we take the filtering of the moving pinnae into account, (ii) we use a model of the echolocation task faced by Rhinolophidae to estimate the effect of any alterations to the emission beam on the echolocation performance of the bat, and (iii) we validate our simulations using a physical mock-up of the morphology of R. rouxi. In contrast to Zhuang & Muller, we find the furrows to focus the emitted energy across the whole range of frequencies contained in the calls of R. rouxi (both in simulations and in measurements). Depending on the frequency, the focusing effect of the furrows has different consequences for the estimated echolocation performance. We argue that the furrows act to focus the beam in order to reduce the influence of clutter echoes.

  14. Species and acoustic diversity of bats in a palaeotropical wet evergreen forest in southern India

    OpenAIRE

    Raghuram, H; Jain, M; Balakrishnan, R

    2014-01-01

    The Western Ghats of India is among the top 25 biodiversity hotspots in the world. About 43% of the reported 117 bat species in India are found in this region, but few quantitative studies of bat echolocation calls and diversity have been carried out here thus far. A quantitative study of bat diversity was therefore conducted using standard techniques, including mist-netting, acoustical and roost surveys in the wet evergreen forests of Kudremukh National Park in the Western Ghats of Karnataka...

  15. Single-locus species delimitation: a test of the mixed Yule–coalescent model, with an empirical application to Philippine round-leaf bats

    OpenAIRE

    Esselstyn, Jacob A.; Evans, Ben J.; Sedlock, Jodi L.; Anwarali Khan, Faisal Ali; Heaney, Lawrence R.

    2012-01-01

    Prospects for a comprehensive inventory of global biodiversity would be greatly improved by automating methods of species delimitation. The general mixed Yule–coalescent (GMYC) was recently proposed as a potential means of increasing the rate of biodiversity exploration. We tested this method with simulated data and applied it to a group of poorly known bats (Hipposideros) from the Philippines. We then used echolocation call characteristics to evaluate the plausibility of species boundaries s...

  16. Modeling of Habitat and Foraging Behavior of Beaked Whales in the Southern California Bight

    Science.gov (United States)

    2015-09-30

    a species label. Data from acoustic line-transect surveys (2008-2011) carried out by NOAA Southwest Fisheries Science Center (Jay Barlow ) in...published, refereed] Baumann-Pickering S, Yack TM, Barlow J, Wiggins SM, Hildebrand JA (2013) Baird’s beaked whale echolocation signals. J Acoust Soc Am 133...4321-4331 [published, refereed] Yack TM, Barlow J, Calambokidis J, Southall B, and Coates S (2013) Identification of previously unknown beaked

  17. Cetacean Social Behavioral Response to Sonar Exposure

    Science.gov (United States)

    2015-09-30

    likely a social response which anticipates against potential loss of social cohesion, which may be induced by masking of their communication signals...Discrimination of fast click series produced by Risso’s dolphins for echolocation or communication . Wensveen P. et al (in review). The effectiveness of ramp...up of naval sonar to reduce sound levels received by marine mammals : experimental tests with humpback whales. Kvadsheim et al. (2015). The 3S2

  18. Propagation of sound

    DEFF Research Database (Denmark)

    Wahlberg, Magnus; Larsen, Ole Næsbye

    2017-01-01

    properties can be modified by sound absorption, refraction, and interference from multi paths caused by reflections.The path from the source to the receiver may be bent due to refraction. Besides geometrical attenuation, the ground effect and turbulence are the most important mechanisms to influence...... communication sounds for airborne acoustics and bottom and surface effects for underwater sounds. Refraction becomes very important close to shadow zones. For echolocation signals, geometric attenuation and sound absorption have the largest effects on the signals....

  19. Tactile maze solving in congenitally blind individuals

    DEFF Research Database (Denmark)

    Gagnon, Léa; Kupers, Ron; Schneider, Fabien C

    2010-01-01

    and environmental cues such as temperature and echolocation. We hypothesize that by limiting these cues, blind individuals will lose their advantage compared with controls in spatial navigation tasks. We therefore evaluated the performance of blind and sighted individuals in small-scale, tactile multiple T mazes....... Our results show that blindfolded sighted controls outperformed blind participants in the route-learning tasks. This suggests that, contrary to indoor large-scale spaces, navigational skills inside small-scale spaces benefit from visual experience....

  20. Multidimensional Signal Processing for Sensing & Communications

    Science.gov (United States)

    2015-07-29

    Spectrum Sensing,” submitted to IEEE Intl. Workshop on Computational Advances in Multi-Sensor Adaptive Processing, Cancun, Mexico , 13-16 Dec. 2015...Sensing,” submitted to IEEE Intl. Workshop on Computational Advances in Multi-Sensor Adaptive Processing, Cancun, Mexico , 13-16 Dec. 2015...diversity in echolocating mammals ,” IEEE Signal Processing Magazine, vol. 26, no. 1, pp. 65- 75, Jan. 2009. DISTRIBUTION A: Distribution approved for

  1. Bat detective—Deep learning tools for bat acoustic signal detection

    Science.gov (United States)

    Barlow, Kate E.; Firman, Michael; Freeman, Robin; Harder, Briana; Kinsey, Libby; Mead, Gary R.; Newson, Stuart E.; Pandourski, Ivan; Russ, Jon; Szodoray-Paradi, Abigel; Tilova, Elena; Girolami, Mark; Jones, Kate E.

    2018-01-01

    Passive acoustic sensing has emerged as a powerful tool for quantifying anthropogenic impacts on biodiversity, especially for echolocating bat species. To better assess bat population trends there is a critical need for accurate, reliable, and open source tools that allow the detection and classification of bat calls in large collections of audio recordings. The majority of existing tools are commercial or have focused on the species classification task, neglecting the important problem of first localizing echolocation calls in audio which is particularly problematic in noisy recordings. We developed a convolutional neural network based open-source pipeline for detecting ultrasonic, full-spectrum, search-phase calls produced by echolocating bats. Our deep learning algorithms were trained on full-spectrum ultrasonic audio collected along road-transects across Europe and labelled by citizen scientists from www.batdetective.org. When compared to other existing algorithms and commercial systems, we show significantly higher detection performance of search-phase echolocation calls with our test sets. As an example application, we ran our detection pipeline on bat monitoring data collected over five years from Jersey (UK), and compared results to a widely-used commercial system. Our detection pipeline can be used for the automatic detection and monitoring of bat populations, and further facilitates their use as indicator species on a large scale. Our proposed pipeline makes only a small number of bat specific design decisions, and with appropriate training data it could be applied to detecting other species in audio. A crucial novelty of our work is showing that with careful, non-trivial, design and implementation considerations, state-of-the-art deep learning methods can be used for accurate and efficient monitoring in audio. PMID:29518076

  2. Bat detective-Deep learning tools for bat acoustic signal detection.

    Science.gov (United States)

    Mac Aodha, Oisin; Gibb, Rory; Barlow, Kate E; Browning, Ella; Firman, Michael; Freeman, Robin; Harder, Briana; Kinsey, Libby; Mead, Gary R; Newson, Stuart E; Pandourski, Ivan; Parsons, Stuart; Russ, Jon; Szodoray-Paradi, Abigel; Szodoray-Paradi, Farkas; Tilova, Elena; Girolami, Mark; Brostow, Gabriel; Jones, Kate E

    2018-03-01

    Passive acoustic sensing has emerged as a powerful tool for quantifying anthropogenic impacts on biodiversity, especially for echolocating bat species. To better assess bat population trends there is a critical need for accurate, reliable, and open source tools that allow the detection and classification of bat calls in large collections of audio recordings. The majority of existing tools are commercial or have focused on the species classification task, neglecting the important problem of first localizing echolocation calls in audio which is particularly problematic in noisy recordings. We developed a convolutional neural network based open-source pipeline for detecting ultrasonic, full-spectrum, search-phase calls produced by echolocating bats. Our deep learning algorithms were trained on full-spectrum ultrasonic audio collected along road-transects across Europe and labelled by citizen scientists from www.batdetective.org. When compared to other existing algorithms and commercial systems, we show significantly higher detection performance of search-phase echolocation calls with our test sets. As an example application, we ran our detection pipeline on bat monitoring data collected over five years from Jersey (UK), and compared results to a widely-used commercial system. Our detection pipeline can be used for the automatic detection and monitoring of bat populations, and further facilitates their use as indicator species on a large scale. Our proposed pipeline makes only a small number of bat specific design decisions, and with appropriate training data it could be applied to detecting other species in audio. A crucial novelty of our work is showing that with careful, non-trivial, design and implementation considerations, state-of-the-art deep learning methods can be used for accurate and efficient monitoring in audio.

  3. Acoustic location of conspecifics in a nocturnal bird: the corncrake Crex crex

    OpenAIRE

    Ręk, Paweł

    2013-01-01

    Although the use of sounds in spatial orientation is widespread among animals, only a few groups advanced such specific adaptations as echolocation. In contrast, practically all animals and night-active species in particular, must occasionally orient themselves relative to invisible but audible objects such as a hidden rival or predator. In this study, I would like to determine the impact of locating which involves the use of acoustic parameters of sender’s vocalisations by receivers and chan...

  4. Neural network modeling of a dolphin's sonar discrimination capabilities

    OpenAIRE

    Andersen, Lars Nonboe; René Rasmussen, A; Au, WWL; Nachtigall, PE; Roitblat, H.

    1994-01-01

    The capability of an echo-locating dolphin to discriminate differences in the wall thickness of cylinders was previously modeled by a counterpropagation neural network using only spectral information of the echoes [W. W. L. Au, J. Acoust. Soc. Am. 95, 2728–2735 (1994)]. In this study, both time and frequency information were used to model the dolphin discrimination capabilities. Echoes from the same cylinders were digitized using a broadband simulated dolphin sonar signal with the transducer ...

  5. Temperature, productivity and sediment characteristics as drivers of seasonal and spatial variations of dissolved methane in the near-shore coastal areas (Belgian coastal zone, North Sea)

    Science.gov (United States)

    Borges, Alberto V.; Speeckaert, Gaëlle; Champenois, Willy; Scranton, Mary I.; Gypens, Nathalie

    2017-04-01

    The open ocean is a modest source of CH4 to the atmosphere compared to other natural and anthropogenic CH4 emissions. Coastal regions are more intense sources of CH4 to the atmosphere than open oceanic waters, in particular estuarine zones. The CH4 emission to the atmosphere from coastal areas is sustained by riverine inputs and methanogenesis in the sediments due to high organic matter (OM) deposition. Additionally, natural gas seeps are sources of CH4 to bottom waters leading to high dissolved CH4 concentrations in bottom waters (from tenths of nmol L-1 up to several µmol L-1). We report a data set of dissolved CH4 concentrations obtained at nine fixed stations in the Belgian coastal zone (Southern North Sea), during one yearly cycle, with a bi-monthly frequency in spring, and a monthly frequency during the rest of the year. This is a coastal area with multiple possible sources of CH4 such as from rivers and gassy sediments, and where intense phytoplankton blooms are dominated by the high dimethylsulfoniopropionate (DMSP) producing micro-algae Phaeocystis globosa, leading to DMSP and dimethylsulfide (DMS) concentrations. Furthermore, the BCZ is a site of important OM sedimentation and accumulation unlike the rest of the North Sea. Spatial variations of dissolved CH4 concentrations were very marked with a minimum yearly average of 9 nmol L-1 in one of the most off-shore stations and maximum yearly average of 139 nmol L-1 at one of the most near-shore stations. The spatial variations of dissolved CH4 concentrations were related to the organic matter (OM) content of sediments, although the highest concentrations seemed to also be related to inputs of CH4 from gassy sediments associated to submerged peat. In the near-shore stations with fine sand or muddy sediments with a high OM content, the seasonal cycle of dissolved CH4 concentration closely followed the seasonal cycle of water temperature, suggesting the control of methanogenesis by temperature in these OM

  6. Active listening for spatial orientation in a complex auditory scene.

    Science.gov (United States)

    Moss, Cynthia F; Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

    2006-04-01

    To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

  7. Active listening for spatial orientation in a complex auditory scene.

    Directory of Open Access Journals (Sweden)

    Cynthia F Moss

    2006-04-01

    Full Text Available To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

  8. Long-Term Monitoring of Dolphin Biosonar Activity in Deep Pelagic Waters of the Mediterranean Sea.

    Science.gov (United States)

    Caruso, Francesco; Alonge, Giuseppe; Bellia, Giorgio; De Domenico, Emilio; Grammauta, Rosario; Larosa, Giuseppina; Mazzola, Salvatore; Riccobene, Giorgio; Pavan, Gianni; Papale, Elena; Pellegrino, Carmelo; Pulvirenti, Sara; Sciacca, Virginia; Simeone, Francesco; Speziale, Fabrizio; Viola, Salvatore; Buscaino, Giuseppa

    2017-06-28

    Dolphins emit short ultrasonic pulses (clicks) to acquire information about the surrounding environment, prey and habitat features. We investigated Delphinidae activity over multiple temporal scales through the detection of their echolocation clicks, using long-term Passive Acoustic Monitoring (PAM). The Istituto Nazionale di Fisica Nucleare operates multidisciplinary seafloor observatories in a deep area of the Central Mediterranean Sea. The Ocean noise Detection Experiment collected data offshore the Gulf of Catania from January 2005 to November 2006, allowing the study of temporal patterns of dolphin activity in this deep pelagic zone for the first time. Nearly 5,500 five-minute recordings acquired over two years were examined using spectrogram analysis and through development and testing of an automatic detection algorithm. Echolocation activity of dolphins was mostly confined to nighttime and crepuscular hours, in contrast with communicative signals (whistles). Seasonal variation, with a peak number of clicks in August, was also evident, but no effect of lunar cycle was observed. Temporal trends in echolocation corresponded to environmental and trophic variability known in the deep pelagic waters of the Ionian Sea. Long-term PAM and the continued development of automatic analysis techniques are essential to advancing the study of pelagic marine mammal distribution and behaviour patterns.

  9. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis) in the Pearl River Estuary, China

    Science.gov (United States)

    Wang, Zhi-Tao; Nachtigall, Paul E.; Akamatsu, Tomonari; Wang, Ke-Xiong; Wu, Yu-Ping; Liu, Jian-Chang; Duan, Guo-Qin; Cao, Han-Jiang; Wang, Ding

    2015-01-01

    A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world’s largest known population of Indo-Pacific humpback dolphins (Sousa chinensis). Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts. PMID:26580966

  10. The aerodynamic cost of head morphology in bats: maybe not as bad as it seems.

    Science.gov (United States)

    Vanderelst, Dieter; Peremans, Herbert; Razak, Norizham Abdul; Verstraelen, Edouard; Dimitriadis, Grigorios; Dimitriadis, Greg

    2015-01-01

    At first sight, echolocating bats face a difficult trade-off. As flying animals, they would benefit from a streamlined geometric shape to reduce aerodynamic drag and increase flight efficiency. However, as echolocating animals, their pinnae generate the acoustic cues necessary for navigation and foraging. Moreover, species emitting sound through their nostrils often feature elaborate noseleaves that help in focussing the emitted echolocation pulses. Both pinnae and noseleaves reduce the streamlined character of a bat's morphology. It is generally assumed that by compromising the streamlined charactered of the geometry, the head morphology generates substantial drag, thereby reducing flight efficiency. In contrast, it has also been suggested that the pinnae of bats generate lift forces counteracting the detrimental effect of the increased drag. However, very little data exist on the aerodynamic properties of bat pinnae and noseleaves. In this work, the aerodynamic forces generated by the heads of seven species of bats, including noseleaved bats, are measured by testing detailed 3D models in a wind tunnel. Models of Myotis daubentonii, Macrophyllum macrophyllum, Micronycteris microtis, Eptesicus fuscus, Rhinolophus formosae, Rhinolophus rouxi and Phyllostomus discolor are tested. The results confirm that non-streamlined facial morphologies yield considerable drag forces but also generate substantial lift. The net effect is a slight increase in the lift-to-drag ratio. Therefore, there is no evidence of high aerodynamic costs associated with the morphology of bat heads.

  11. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis) in the Pearl River Estuary, China.

    Science.gov (United States)

    Wang, Zhi-Tao; Nachtigall, Paul E; Akamatsu, Tomonari; Wang, Ke-Xiong; Wu, Yu-Ping; Liu, Jian-Chang; Duan, Guo-Qin; Cao, Han-Jiang; Wang, Ding

    2015-01-01

    A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis). Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.

  12. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis in the Pearl River Estuary, China.

    Directory of Open Access Journals (Sweden)

    Zhi-Tao Wang

    Full Text Available A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis. Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.

  13. The detection of 'virtual' objects using echoes by humans: Spectral cues.

    Science.gov (United States)

    Rowan, Daniel; Papadopoulos, Timos; Archer, Lauren; Goodhew, Amanda; Cozens, Hayley; Lopez, Ricardo Guzman; Edwards, David; Holmes, Hannah; Allen, Robert

    2017-07-01

    Some blind people use echoes to detect discrete, silent objects to support their spatial orientation/navigation, independence, safety and wellbeing. The acoustical features that people use for this are not well understood. Listening to changes in spectral shape due to the presence of an object could be important for object detection and avoidance, especially at short range, although it is currently not known whether it is possible with echolocation-related sounds. Bands of noise were convolved with recordings of binaural impulse responses of objects in an anechoic chamber to create 'virtual objects', which were analysed and played to sighted and blind listeners inexperienced in echolocation. The sounds were also manipulated to remove cues unrelated to spectral shape. Most listeners could accurately detect hard flat objects using changes in spectral shape. The useful spectral changes for object detection occurred above approximately 3 kHz, as with object localisation. However, energy in the sounds below 3 kHz was required to exploit changes in spectral shape for object detection, whereas energy below 3 kHz impaired object localisation. Further recordings showed that the spectral changes were diminished by room reverberation. While good high-frequency hearing is generally important for echolocation, the optimal echo-generating stimulus will probably depend on the task. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Satellite tracking of harbour seals on Horns Reef - Use of the Horns Reef wind farm area and the North Sea

    International Nuclear Information System (INIS)

    Tougaard, J.; Tougaard, S.; Jensen, Thyge; Ebbesen, I.; Teilmann, J.

    2003-03-01

    Ten harbour seals (Phoca vitulina) caught on the Danish Wadden Sea island Roemoe were equipped with satellite linked time depth recorders. The animals were caught on three separate occasions (Jan. 4th, Feb. 18th and May 6th, 2002). The transmitters worked between 49 and 100 days, relaying positional and dive information back via the ARGOS satellite service until beginning of July. Background for the studies is the construction of the Worlds largest off shore wind farm on Horns Reef. Based on previous studies using VHF-transmitters, it was expected that the seals would spend considerable time on Horns Reef. The VHF-telemetry studies showed that the preferred direction for seals leaving the Danish Wadden Sea is NW from Graedyb tidal area outside Esbjerg, the direction directly towards the wind farm area. The previously used VHF-transmitters had a limited detection range and it was decided to equip a number of seals from the same area as before with satellite transmitters. This allows for positioning of the seals in the entire North Sea as well as providing dive summary information, as a transmitter with a depth transducer was chosen for the study. Positional information revealed that animals move about more extensively than previously believed. Substantial variation between animals was observed and each seal seemed to have adopted its own foraging strategy. Some animals travelled to the centre of the North Sea on foraging trips and spent considerable time close to the bottom at 30-70 meters depth. Other seals remained in the German Bight and yet others spent considerable time on and around Horns Reef. The area of Horns reef wind farm constitutes a negligible fraction of the total area visited by the tagged seals. The reef as a whole however, appears to be important to the seals both for foraging and as transit area to other feeding grounds further off shore. The resolution in positional information is not sufficiently high to allow for a detailed study of the effects

  15. Background noise levels and correlation with ship traffic in the Gulf of Catania

    Science.gov (United States)

    Viola, Salvatore; Buscaino, Giuseppa; Caruso, Francesco; Chierici, Francesco; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Grammauta, Roasario; Larosa, Giuseppina; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Riccobene, Giorgio; Sciacca, Virginia; Simeone, Francesco; Beranzoli, Laura; Marinaro, Giuditta

    2015-04-01

    In the last decades the growing interest in the evaluation of the underwater acoustic noise for studies in the fields of geology, biology and high-energy physics is driving the scientific community to collaborate towards a multidisciplinary approach to the topic. In June 2012 in the framework of the European project EMSO, a multidisciplinary underwater observatory, named NEMO-SN1, was installed 25 km off-shore the port of Catania, at a depth of 2100 m and operated until May 2013 by INFN (Istituto Nazionale di Fisica Nucleare) and INGV (Istituto Nazionale di Geofisica e Vulcanologia). NEMO-SN1 hosted aboard geophysical, oceanographic and acoustic sensors: among these a seismic hydrophone model SMID DT-405D(V). In this work, conducted within the activity of the SMO project, the results on the evaluation of the underwater acoustic pollution in the Gulf of Catania through SMID DT-405D(V) recordings are presented. The seismic hydrophone provided a data set of about 11 months of continuous (24/7) recordings. Underwater sounds have been continuously digitized at a sampling frequency of 2 kHz and the acquired data have been stored in 10min long files for off-line analysis. To describe one-year background noise levels, the mean integrated acoustic noise was measured every second (sampling frequency 2000, NFFT 2048) in the 1/3 octave bands with centre frequency 63 Hz and for each 10 minutes-long file the 5th, the 50th and the 98th percentiles were calculated. Measured noise was correlated with the shipping traffic in the area, thanks to the data provided by an AIS receiver installed at the INFN-Laboratori Nazionali del Sud. An acoustic noise increment was measured in coincidence with the passing of crafts in the area and it was possible to identify the characteristic spectrum of each ship. A simple model for the estimation of the acoustic noise induced by the ships passing through the area was developed. The model was applied by using AIS data acquired during the operation

  16. Anomalous Structure of Oceanic Lithosphere in the North Atlantic and Arctic Oceans: A Preliminary Analysis Based on Bathymetry, Gravity and Crustal Structure

    Science.gov (United States)

    Barantsrva, O.

    2014-12-01

    We present a preliminary analysis of the crustal and upper mantle structure for off-shore regions in the North Atlantic and Arctic oceans. These regions have anomalous oceanic lithosphere: the upper mantle of the North Atlantic ocean is affected by the Iceland plume, while the Arctic ocean has some of the slowest spreading rates. Our specific goal is to constrain the density structure of the upper mantle in order to understand the links between the deep lithosphere dynamics, ocean spreading, ocean floor bathymetry, heat flow and structure of the oceanic lithosphere in the regions where classical models of evolution of the oceanic lithosphere may not be valid. The major focus is on the oceanic lithosphere, but the Arctic shelves with a sufficient data coverage are also included into the analysis. Out major interest is the density structure of the upper mantle, and the analysis is based on the interpretation of GOCE satellite gravity data. To separate gravity anomalies caused by subcrustal anomalous masses, the gravitational effect of water, crust and the deep mantle is removed from the observed gravity field. For bathymetry we use the global NOAA database ETOPO1. The crustal correction to gravity is based on two crustal models: (1) global model CRUST1.0 (Laske, 2013) and, for a comparison, (2) a regional seismic model EUNAseis (Artemieva and Thybo, 2013). The crustal density structure required for the crustal correction is constrained from Vp data. Previous studies have shown that a large range of density values corresponds to any Vp value. To overcome this problem and to reduce uncertainty associated with the velocity-density conversion, we account for regional tectonic variations in the Northern Atlantics as constrained by numerous published seismic profiles and potential-field models across the Norwegian off-shore crust (e.g. Breivik et al., 2005, 2007), and apply different Vp-density conversions for different parts of the region. We present preliminary results

  17. Heterogeneity of the North Atlantic oceanic lithosphere based on integrated analysis of GOCE satellite gravity and geological data

    Science.gov (United States)

    Barantseva, Olga; Artemieva, Irina; Thybo, Hans; Herceg, Matija

    2015-04-01

    We present the results from modelling the gravity and density structure of the upper mantle for the off-shore area of the North Atlantic region. The crust and upper mantle of the region is expected to be anomalous: Part of the region affected by the Icelandic plume has an anomalously shallow bathymetry, whereas the northern part of the region is characterized by ultraslow spreading. In order to understand the links between deep geodynamical processes that control the spreading rate, on one hand, and their manifestations such as oceanic floor bathymetry and heat flow, on the other hand, we model the gravity and density structure of the upper mantle from satellite gravity data. The calculations are based on interpretation of GOCE gravity satellite data for the North Atlantics. To separate the gravity signal responsible for density anomalies within the crust and upper mantle, we subtract the lower harmonics caused by deep density structure of the Earth (the core and the lower mantle). The gravity effect of the upper mantle is calculated by subtracting the gravity effect of the crust for two crustal models. We use a recent regional seismic model for the crustal structure (Artemieva and Thybo, 2013) based om seismic data together with borehole data for sediments. For comparison, similar results are presented for the global CRUST 1.0 model as well (Laske, 2013). The conversion of seismic velocity data for the crustal structure to crustal density structure is crucial for the final results. We use a combination of Vp-to-density conversion based on published laboratory measurements for the crystalline basement (Ludwig, Nafe, Drake, 1970; Christensen and Mooney, 1995) and for oceanic sediments and oceanic crust based on laboratory measurements for serpentinites and gabbros from the Mid-Atlantic Ridge (Kelemen et al., 2004). Also, to overcome the high degree of uncertainty in Vp-to-density conversion, we account for regional tectonic variations in the Northern Atlantics as

  18. Distribution of polycyclic aromatic hydrocarbons (PAHs) in sewage effluent, continental and coastal waters from the Northwestern Mediterrean Sea: Comparison between two contrasted catchment areas (Marseilles Bay and Vermeille coast)

    Science.gov (United States)

    Guigue, Catherine; Ferretto, Nicolas; Méjanelle, Laurence; Tedetti, Marc; Ghiglione, Jean-François; Goutx, Madeleine

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAHs) were analysed from sewage treatment plant waters and surface waters collected in continental (rivers), harbour and off-shore marine sites from Marseilles Bay and Vermeille coastal areas between 2009 and 2013 (Northwestern Mediterranean Sea, France). After collection, water samples were first filtered on glass fiber filters, then PAHs from the dissolved phase were extracted using liquid-liquid or solid phase extraction (SPE) methods, while those from particles were treated according to Bligh and Dyer method. After a possible purification step, extracts were analysed by gas chromatography coupled to mass spectrometry (GC-MS). Regardless of the study area, dissolved and particulate PAH (18 parents + alkylated homologues) concentration averages were 150.2 ± 140.5 ng l-1and 39.4 ± 71.2 ng l-1, respectively. Interestingly, the concentration in dissolved PAHs was on average 3.8 higher than the concentration in particulate PAHs. In addition, a gradient of PAH concentrations was observed from coastal waters with the highest values in harbours and outlet sewage effluents and the lowest values in off-shore marine waters. Intermediate concentrations were recorded in continental waters. In the Marseilles Bay, dissolved PAH concentrations were significantly higher and associated to increased signatures of unburned and combusted fossil fuels, mainly from heating, during the cold period (November-April). In contrast, unburned petroleum signature dominated in the warm period (May-October), emphasizing the intense shipping traffic and urban/industrial activities occurring in one of the largest Mediterranean harbour and city. Conversely, in the Vermeille coastal waters, dissolved PAH concentrations were higher during the warm period when particulate PAHs displayed the lowest concentrations, suggesting a seasonal related partition between dissolved and particulate PAHs. In addition, in the Vermeille coastal waters, PAHs were dominated by

  19. The GMOS contributions to GEOSS

    Directory of Open Access Journals (Sweden)

    Pirrone N.

    2013-04-01

    Full Text Available The Group on Earth Observations (GEO is coordinating efforts to build a Global Earth Observation System of Systems (GEOSS. GEOSS is aimed at providing decision-support tools to a wide variety of users. These tools are addressed toward nine social benefit areas (SBAs that are of critical importance to society. These nine areas are addressed through the GEOSS Common Infrastructure. To support the implementation of the GEOSS Work Plan, two tasks within the Health SBA have been launched: i HE-02-C1: the Global Mercury Observation System and ii HE-02-C2: the Global Monitoring of Persistent Organic Pollutants, Emerging Contaminants and Global Change Indicators. The task HE-02-C1aims to: Increase the availability of Earth observation and information needed to both track pollutants and anticipate changes to the environment. Harmonize standard operating procedures for monitoring pollutants and their compounds in air, water, soil, sediments, vegetation and biota. Understand the temporal and spatial patterns of pollutant transport, deposition to, and evasion from, terrestrial and aquatic ecosystems. Support the validation of regional and global atmospheric pollutant models for use in evaluating different policy options. Evaluate the effectiveness of international efforts to reduce pollutant releases. The overarching goal of HE-02-C1 is the development of a global observation system for mercury, realized by harmonizing standard operating procedures for monitoring mercury and its compounds in air, precipitation samples, surface water, soil, sediments, vegetation and biota. The sharing of data from this network, which allows access to data that is comparable, long-term, and from a large number of ground-based and off-shore sites, will help us understand temporal and spatial patterns of mercury transport and deposition to, and evasion from, terrestrial and aquatic ecosystems. The data produced (at 40 ground-based sites, off-shore locations throughout the

  20. Wind power: Areva acquires a 51% stake in Multibrid

    International Nuclear Information System (INIS)

    2007-01-01

    AREVA announced the acquisition of a 51% stake in Multibrid, a designer and manufacturer of multi-megawatt off-shore wind turbines based in Germany. With this acquisition, AREVA has entered into a joint venture with Prokon Nord, a German off-shore wind turbine and biomass plant developer and current owner of Multibrid. This transaction values Multibrid at euro 150 million. AREVA plans to rapidly further develop Multibrid's activities by giving the company access to its industrial resources, financial base and international commercial network. In return, Multibrid will provide AREVA with its leading-edge technology which, developed for 5 MW turbines, can achieve a very high output while reducing operating costs thanks to a simplified maintenance system. With this stake in Multibrid, AREVA aims to increase its presence on the offshore wind market that meets land settlement requirements and that should grow significantly in the years to come (from 300 MW in Europe today to an expected 1400 MW by 2011). As an exclusive supplier of Prokon Nord, Multibrid will participate in projects such as Borkum West (30 MW), the first offshore project in Germany, Borkum West 2 (400 MW), and Cote d'Albatre (105 MW), the first offshore wind farm project in France. The stake in Multibrid strengthens AREVA's strategic positioning on the CO 2 -free energy market, thanks to complementary solutions ranging from nuclear technologies to renewables. A number of recent achievements illustrate this strategy: - bio-energy (crucial energy supply in numerous rural areas): delivery of turnkey biomass power plants; ongoing construction of 10 plants in India, Thailand and Brazil; future development plans in fast-growing regions, such as Latin America; - wind power: Multibrid adds to the Group's stake in REpower and to its partnership with Suzlon for which AREVA is the number one supplier of transmission and distribution solutions for wind power; - hydrogen and fuel cells: design and manufacture of