Radar imaging mechanism of the Birkenfels wreck in the southern North Sea

Varying tidal currents close to the sea bed cause sediment motion around wrecks leading to formation of scour holes and sand ribbons. Consequently, scouring destabilizes the position and shape of wrecks. Changing water depths above the shallowest parts of wrecks due to such sediment displacements can be crucial for the safety of ship navigation. For that reason, many wreck positions must be routinely re-surveyed. In 2008 changes occurred at 12 % of 259 investigated wrecks in German sea areas compared with the last survey. Especially lower water depths above wrecks have been measured. Therefore, basic research is still necessary to achieve new insights of wave- and current-induced sand transport in the boundary layer of the sea bed covered by wrecks and sand ribbons. Here, it will be focused on the role of active microwave remote sensing potentials for studying radar signatures at the water surface caused by submerged wrecks. The Ka band radar imaging mechanism of the submerged wreck/sand ribbon of the motor vessel (M/V) Birkenfels in the southern North Sea is investigated by applying the quasi-specular scattering theory and considering the capillary as well as the gravity wave ranges of the wave energy density spectrum. Multi-beam echo sounder images of the Birkenfels wreck and associated sand ribbons as well as other available environmental in situ data have been analyzed. The formation of sand ribbons at the sea bed and the manifestation of its radar signatures at the water surface are caused by an elliptical vortex or helical flow cell triggered by unidirectional tidal current flow interacting with the wreck. The difference of simulated and measured normalized radar cross section (NRCS) modulation as a function of the space variable is less than 31.6%. Results are presented for NRCS simulations dependent on position for different effective incidence angles, unidirectional current speeds, wind speeds, and relaxation rates

Development of a trench cutting re-mixing deep wall method model test device

The trench cutting re-mixing deep wall (TRD) is a new type of underground waterproof curtain. Mixing uniformity is the key index affecting the efficiency and quality of this method. However, because of many influencing factors, existing theories cannot be used to express the relationship between various factors and mixing uniformity. By analyzing the cutting and mixing process of the TRD method, the main factors affecting the uniformity of the mixing were obtained. A model test device was designed and manufactured, based on Buckingham's pi theorem. The validity of the model test device was verified through a comparative analysis of model and field test results. The model test device was demonstrated to be able to simulate the mixing process of the TRD method. The results provide guidance for promotion and better application of the TRD method

Kickin\u27 Sand and Tellin\u27 Lies

This document is the script of the two-act play, Kickin’ Sand and Tellin’ Lies, by Jackson B. Miller and Christopher Forrer. The Linfield College Theatre Program presented the world premieres of the play in November 2012 in McMinnville, Oregon and in Pacific City, Oregon. The play was created as part of the Launching through the Surf: The Dory Fleet of Pacific City project, which focuses on the historical and contemporary role of dory fishers and dories in the life of the coastal village of Pacific City, Oregon. Inspired by stories from the project, Kickin’ Sand and Tellin’ Lies is a fictional work. Inquiries concerning the professional or amateur rights to produce Kickin’ Sand and Tellin’ Lies, or any part thereof, should be addressed to Jackson B. Miller ([email protected]) or the Department of Theatre and Communication Arts, Linfield College, 900 SE Baker St., McMinnville, OR 97128 (503-883-2802).https://digitalcommons.linfield.edu/dory_kstl_play/1002/thumbnail.jp

Carmel River Lagoon Enhancement Project: Water Quality and Aquatic Wildlife Monitoring, 2005-6

In summer and fall 2004, the California Department of Parks and Recreation (DPR) initiated the Carmel River Lagoon Enhancement Project. The project involved excavation of a dry remnant Arm of the lagoon and adjacent disused farmland to form a significant new lagoon volume. The intention was to provide habitat, in particular, for two Federally threatened species: the California Red-Legged Frog, and the Steelhead Trout (South Central-Coastal California Evolutionary Significant Unit). DPR contracted with the Foundation of California State University Monterey Bay (Central Coast Watershed Studies Team, Watershed Institute) to monitor water quality and aquatic invertebrates in association with the enhancement, and to attempt to monitor steelhead using novel video techniques. The monitoring objective was to assess whether the enhancement was successful in providing habitat with good water quality, adequate invertebrate food for steelhead, and ultimately the presence of steelhead. (Document contains 102 pages

Robotic Tankette for Intelligent BioEnergy Agriculture: Design, Development and Field Tests

In recent years, the use of robots in agriculture has been increasing mainly due to the high demand of productivity, precision and efficiency, which follow the climate change effects and world population growth. Unlike conventional agriculture, sugarcane farms are usually regions with dense vegetation, gigantic areas, and subjected to extreme weather conditions, such as intense heat, moisture and rain. TIBA - Tankette for Intelligent BioEnergy Agriculture - is the first result of an R&D project which strives to develop an autonomous mobile robotic system for carrying out a number of agricultural tasks in sugarcane fields. The proposed concept consists of a semi-autonomous, low-cost, dust and waterproof tankette-type vehicle, capable of infiltrating dense vegetation in plantation tunnels and carry several sensing systems, in order to perform mapping of hard-to-access areas and collecting samples. This paper presents an overview of the robot mechanical design, the embedded electronics and software architecture, and the construction of a first prototype. Preliminary results obtained in field tests validate the proposed conceptual design and bring about several challenges and potential applications for robot autonomous navigation, as well as to build a new prototype with additional functionality.Comment: 9 pages, 15 figure

Why are probabilistic laws governing quantum mechanics and neurobiology?

We address the question: Why are dynamical laws governing in quantum mechanics and in neuroscience of probabilistic nature instead of being deterministic? We discuss some ideas showing that the probabilistic option offers advantages over the deterministic one.Comment: 40 pages, 8 fig

Modelling Washboard Road: from experimental measurements to linear stability analysis

When submitted to the repeated passages of vehicles unpaved roads made of sand or gravel can develop a ripply pattern known as washboard or corrugated road. We propose a stability analysis based on experimental measurements of the force acting on a blade (or plow) dragged on a circular sand track and show that a linear model is sufficient to describe the instability near onset. The relation between the trajectory of the plow and the profile of the sand bed left after its passage is studied experimentally. The various terms in the expression of the lift force created by the flow of granular material on the plow are determined up to first order by imposing a sinusoidal trajectory to the blade on an initially flat sand bed, as well as by imposing a horizontal trajectory on an initially rippled sand bed. Our model recovers all the previously observed features of washboard road and accurately predicts the most unstable wavelength near onset as well as the critical velocity for the instability.Comment: 9 pages, 10 figure