P.W. Wessels

Bio: P.W. Wessels is an academic researcher from Netherlands Organisation for Applied Scientific Research. The author has contributed to research in topics: Industrial noise & Noise control. The author has an hindex of 5, co-authored 11 publications receiving 104 citations.

Common sole larvae survive high levels of pile-driving sound in controlled exposure experiments.

Abstract: In view of the rapid extension of offshore wind farms, there is an urgent need to improve our knowledge on possible adverse effects of underwater sound generated by pile-driving. Mortality and injuries have been observed in fish exposed to loud impulse sounds, but knowledge on the sound levels at which (sub-)lethal effects occur is limited for juvenile and adult fish, and virtually non-existent for fish eggs and larvae. A device was developed in which fish larvae can be exposed to underwater sound. It consists of a rigid-walled cylindrical chamber driven by an electro-dynamical sound projector. Samples of up to 100 larvae can be exposed simultaneously to a homogeneously distributed sound pressure and particle velocity field. Recorded pile-driving sounds could be reproduced accurately in the frequency range between 50 and 1000 Hz, at zero to peak pressure levels up to 210 dB re 1mPa2 (zero to peak pressures up to 32 kPa) and single pulse sound exposure levels up to 186 dB re 1mPa2s. The device was used to examine lethal effects of sound exposure in common sole (Solea solea) larvae. Different developmental stages were exposed to various levels and durations of pile-driving sound. The highest cumulative sound exposure level applied was 206 dB re 1mPa2s, which corresponds to 100 strikes at a distance of 100 m from a typical North Sea pile-driving site. The results showed no statistically significant differences in mortality between exposure and control groups at sound exposure levels which were well above the US interim criteria for non-auditory tissue damage in fish. Although our findings cannot be extrapolated to fish larvae in general, as interspecific differences in vulnerability to sound exposure may occur, they do indicate that previous assumptions and criteria may need to be revised.

Intelligent autonomous vehicles with an extendable knowledge base under meaningful human control

Abstract: Intelligent robotic autonomous systems (unmanned aerial/ground/surface/underwater vehicles) are attractive for military application to relieve humans from tedious or dangerous tasks. These systems require awareness of the environment and their own performance to reach a mission goal. This awareness enables them to adapt their operations to handle unexpected changes in the environment and uncertainty in assessments. Components of the autonomous system cannot rely on perfect awareness or actuator execution, and mistakes of one component can affect the entire system. To obtain a robust system, a system-wide approach is needed and a realistic model of all aspects of the system and its environment. In this paper, we present our study on the design and development of a fully functional autonomous system, consisting of sensors, observation processing and behavior analysis, information database, knowledge base, communication, planning processes, and actuators. The system behaves as a teammate of a human operator and can perform tasks independently with minimal interaction. The system keeps the human informed about relevant developments that may require human assistance, and the human can always redirect the system with high-level instructions. The communication behavior is implemented as a Social AI Layer (SAIL). The autonomous system was tested in a simulation environment to support rapid prototyping and evaluation. The simulation is based on the Robotic Operating System (ROS) with fully modelled sensors and actuators and the 3D graphics-enabled physics simulation software Gazebo. In this simulation, various flying and driving autonomous systems can execute their tasks in a realistic 3D environment with scripted or user-controlled threats. The results show the performance of autonomous operation as well as interaction with humans

Effect of pile-driving sounds on the survival of larval fish (abstract)

Abstract: In view of the rapid extension of offshore wind farms, there is an urgent need to improve our knowledge on possible adverse effects of underwater sound generated by pile-driving. Mortality and injuries have been observed in fish exposed to loud impulse sounds, but knowledge on the sound levels at which (sub-)lethal effects occur is limited, especially for fish larvae. A device was developed in which recorded pile-driving noise can be reproduced accurately in the frequency range between 50 and 1000Hz, at zero-to-peak pressure levels up to 210 dB re 1μPa2 (zero-to-peak pressures up to 32 kPa) and single pulse sound exposure levels up to 186 dB re 1μPa2s. This device was used to examine lethal effects of sound exposure in common sole (Solea solea) larvae. Different developmental stages were exposed to various levels and durations of pile-driving noise. The highest cumulative sound exposure level applied was 206 dB re 1μPa2s, which corresponds to 100 strikes at a distance of 100 m from a typical North Sea piledriving site. The results showed no statistically significant differences in mortality between exposure and control groups at sound exposure levels which were well above the US interim criteria for non-auditory tissue damage in fish. These findings cannot be extrapolated to fish larvae in general, as interspecific differences in vulnerability to sound exposure may occur. Therefore, controlled exposure experiments are currently being carried out for European sea bass (Dicentrarchus labrax) larvae and will be carried out for herring (Clupea harengus) larvae in the near future.

Fusion of multiple microphone array data for localizing sound sources in an industrial area

Abstract: Locating sound sources that contribute to noise annoyance near large industrial areas under different meteorological conditions is a hard problem. Permanently installed microphone arrays at the edges of an industrial area allow to determine the direction of arrival of the sound at their location. Several algorithms have been proposed for this purpose yet not all of them are robust against changes in effective sound speed and loss of coherence. Therefore algorithm parameters have to be chosen carefully. In addition, in this paper, a probabilistic approach is proposed to combine the information obtained from three or more arrays. The methodology accounts for the effect of wind and temperature on the direction of arrival. It also estimates uncertainty caused by uncertainty in the local meteorological situation, ground impedance, and presence of typical harbor objects such as stacked containers and piles of coal, etc. The proposed methodology is applied to an industrial area of over 10 kilometer squared and the consistency of detected sources under varying weather conditions is investigated. This shows the validity of the approach.

Time varying sound propagation for a large industrial area

Abstract: The distance between noise sources at a large industrial area and a local community can be in the order of several kilometers. At such distances it may not be clear which sources are the main contributors to possible noise complaints. A long-term monitoring project is described that measures the sound sources in the industrial area and the sound in the nearby residential area. This paper focuses on the time varying sound propagation that is needed to determine the industrial source strengths and the relevance of the sources for the nearby community. Data from a meteorological model is combined with measurements from four geographically distributed meteorological masts via data assimilation. In this way the wind and temperature, as a function of height and time, between all possible source and receiver locations can be determined. Next, the corresponding sound propagation for all transfer paths is obtained near real time as these have been calculated beforehand. It will be shown that this monitoring project captures the time varying industrial noise as perceived in the residential area, whereas a standard noise model uses a constant sound propagation based on an average meteorology. This approach makes a comparison with registered complaints over time meaningful. © 2016, German Acoustical Society (DEGA). All rights reserved.

Assessing environmental impacts of offshore wind farms: lessons learned and recommendations for the future

Abstract: Offshore wind power provides a valuable source of renewable energy that can help reduce carbon emissions. Technological advances are allowing higher capacity turbines to be installed and in deeper water, but there is still much that is unknown about the effects on the environment. Here we describe the lessons learned based on the recent literature and our experience with assessing impacts of offshore wind developments on marine mammals and seabirds, and make recommendations for future monitoring and assessment as interest in offshore wind energy grows around the world. The four key lessons learned that we discuss are: 1) Identifying the area over which biological effects may occur to inform baseline data collection and determining the connectivity between key populations and proposed wind energy sites, 2) The need to put impacts into a population level context to determine whether they are biologically significant, 3) Measuring responses to wind farm construction and operation to determine disturbance effects and avoidance responses, and 4) Learn from other industries to inform risk assessments and the effectiveness of mitigation measures. As the number and size of offshore wind developments increases, there will be a growing need to consider the population level consequences and cumulative impacts of these activities on marine species. Strategically targeted data collection and modeling aimed at answering questions for the consenting process will also allow regulators to make decisions based on the best available information, and achieve a balance between climate change targets and environmental legislation.

Information gaps in understanding the effects of noise on fishes and invertebrates

Abstract: The expansion of shipping and aquatic industrial activities in recent years has led to growing concern about the effects of man-made sounds on aquatic life. Sources include (but are not limited to) pleasure boating, fishing, the shipping of goods, offshore exploration for oil and gas, dredging, construction of bridges, harbors, oil and gas platforms, wind farms and other renewable energy devices, and the use of sonar by commercial and military vessels. There are very substantial gaps in our understanding of the effects of these sounds, especially for fishes and invertebrates. Currently, it is almost impossible to come to clear conclusions on the nature and levels of man-made sound that have potential to cause effects upon these animals. In order to develop a better understanding of effects of man-made sound, this paper identifies the most critical information needs and data gaps on the effects of various sounds on fishes, fisheries, and invertebrates resulting from the use of sound-generating devices. It highlights the major issues and discusses the information currently available on each of the information needs and data gaps. The paper then identifies the critical questions concerning the effects of man-made sounds on aquatic life for which answers are not readily available and articulates the types of information needed to fulfill each of these drivers for information—the key information gaps. Finally, a list of priorities for research and development is presented.

Bioavailability of iron, zinc, and provitamin A carotenoids in biofortified staple crops.

Abstract: International research efforts, including those funded by HarvestPlus, a Challenge Program of the Consultative Group on International Agricultural Research (CGIAR), are focusing on conventional plant breeding to biofortify staple crops such as maize, rice, cassava, beans, wheat, sweet potatoes, and pearl millet to increase the concentrations of micronutrients that are commonly deficient in specific population groups of developing countries. The bioavailability of micronutrients in unfortified staple crops in developing regions is typically low, which raises questions about the efficacy of these crops to improve population micronutrient status. This review of recent studies of biofortified crops aims to assess the micronutrient bioavailability of biofortified staple crops in order to derive lessons that may help direct plant breeding and to infer the potential efficacy of food-based nutrition interventions. Although reducing the amounts of antinutrients and the conduction of food processing generally increases the bioavailability of micronutrients, antinutrients still possess important benefits, and food processing results in micronutrient loss. In general, biofortified foods with relatively higher micronutrient density have higher total absorption rates than nonbiofortified varieties. Thus, evidence supports the focus on efforts to breed plants with increased micronutrient concentrations in order to decrease the influence of inhibitors and to offset losses from processing.

Robot Operating System (ROS) The Complete Reference (Volume 2)

Abstract: Model Predictive Control for Trajectory Tracking of Unmanned Aerial Vehicles Using ROS -- Design of Fuzzy Logic Controllers to ROS-based UAVs -- Flying Multiple UAVs Using ROS -- SkiROS -- A skill-based robot control architecture on top of ROS -- Control of Mobile Robots using ActionLib -- Parametric Identification of the Dynamics of Mobile Robots and Its Application for the Tuning of Controllers in ROS -- ROSLink: Bridging ROS with the Internet-of-Things for Cloud Robotics -- A ROS Package for Dynamic Bandwidth Management in Multi-Robot Systems -- An autonomous companion UAV for the SpaceBot Cup competition 2015. .

Threshold for onset of injury in Chinook salmon from exposure to impulsive pile driving sounds.

Abstract: The risk of effects to fishes and other aquatic life from impulsive sound produced by activities such as pile driving and seismic exploration is increasing throughout the world, particularly with the increased exploitation of oceans for energy production. At the same time, there are few data that provide insight into the effects of these sounds on fishes. The goal of this study was to provide quantitative data to define the levels of impulsive sound that could result in the onset of barotrauma to fish. A High Intensity Controlled Impedance Fluid filled wave Tube was developed that enabled laboratory simulation of high-energy impulsive sound that were characteristic of aquatic far-field, plane-wave acoustic conditions. The sounds used were based upon the impulsive sounds generated by an impact hammer striking a steel shell pile. Neutrally buoyant juvenile Chinook salmon (Oncorhynchus tshawytscha) were exposed to impulsive sounds and subsequently evaluated for barotrauma injuries. Observed injuries ranged from mild hematomas at the lowest sound exposure levels to organ hemorrhage at the highest sound exposure levels. Frequency of observed injuries were used to compute a biological response weighted index (RWI) to evaluate the physiological impact of injuries at the different exposure levels. As single strike and cumulative sound exposure levels (SELss, SELcum respectively) increased, RWI values increased. Based on the results, tissue damage associated with adverse physiological costs occurred when the RWI was greater than 2. In terms of sound exposure levels a RWI of 2 was achieved for 1920 strikes by 177 dB re 1 µPa2⋅s SELss yielding a SELcum of 210 dB re 1 µPa2⋅s, and for 960 strikes by 180 dB re 1 µPa2⋅s SELss yielding a SELcum of 210 dB re 1 µPa2⋅s. These metrics define thresholds for onset of injury in juvenile Chinook salmon.