Testing an Online Spread Pattern Determination Sensor on a Broadcast Fertilizer Spreader

An alternative method for fertilizer spread pattern determination was developed based on predicting where individual fertilizer particles land on the ground, in contrast to the traditional method of collecting the particles in bins (ASAE Standard S341.2). A small broadcast granular fertilizer spreader (Lowery 300) was equipped with an optical sensor designed to measure the velocity and diameter of individual fertilizer particles shortly after they leave the impeller disc. The measured velocity and diameter of individual particles were input into a ballistic model that predicted where particles land on the ground. A total of over 1000 landing spots revealed the spread pattern. The results have shown that the optical sensor is capable of automatically determining the spread pattern of a fertilizer spreader on the fly. The sensor could be a key component in the development of uniformity-controlled fertilizer application systems

Base line studies North Sea wind farms: strategy of approach for pelagic fish

The Dutch Government has decided to allow the construction of a Near Shore Wind Farm (NSW) demonstration project under the condition that a monitoring programme on - among other things - the ecological impacts is carried out. The Dutch government is responsible for providing a thorough description of the ecological reference situation in order to evaluate future effects of planned wind farms. This report describes the detailed plan of approach to establish the occurrence, density, population structure and migration patterns of pelagic fish fauna in the Dutch coastal zone. Sampling sites have been selected such that they cover the planned location of the Near Shore Wind Farm, cover reference sites and provide representative data of the pelagic fish community in the Dutch coastal zone

Development of a tabletop guidance system for educational robots

The guidance of a vehicle in an outdoor setting is typically implemented using a Real Time Kinematic Global Positioning System (RTK-GPS) potentially enhanced by auxiliary sensors such as electronic compasses, rotation encoders, gyroscopes, and vision systems. Since GPS does not function in an indoor setting where educational competitions are often held, an alternative guidance system was developed. This article describes a guidance method that contains a laser-based localization system, which uses a robot-borne single laser transmitter spinning in a horizontal plane at an angular velocity up to 81 radians per second. Sensor arrays positioned in the corners of a flat rectangular table with dimensions of 1.22 m × 1.83 m detected the laser beam passages. The relative time differences among the detections of the laser passages gave an indication of the angles of the sensors with respect to the laser beam transmitter on the robot. These angles were translated into Cartesian coordinates. The guidance of the robot was implemented using a uni-directional wireless serial connection and position feedback from the localization system. Three experiments were conducted to test the system: 1) the accuracy of the static localization system was determined while the robot stood still. In this test the average error among valid measurements was smaller than 0.3 %. However, a maximum of 3.7 % of the measurements were invalid due to several causes. 2) The accuracy of the guidance system was assessed while the robot followed a straight line. The average deviation from this straight line was 3.6 mm while the robot followed a path with a length of approximately 0.9 m. 3) The overall performance of the guidance system was studied while the robot followed a complex path consisting of 33 sub-paths. The conclusion was that the system worked reasonably accurate, unless the robot came in close proximity

Effects of Roads and Traffic on Wildlife Populations and Landscape Function Road Ecology is Moving toward Larger Scales

Road ecology has developed into a significant branch of ecology with steady growth in the number of refereed journal articles, books, conferences, symposia, and “best practice” guidelines being produced each year. The main objective of this special issue of Ecology and Society is to highlight the need for studies that document the population, community, and ecosystem-level effects of roads and traffic by publishing studies that document these effects. It became apparent when compiling this special issue that there is a paucity of studies that explicitly examined higher order effects of roads and traffic. No papers on landscape function or ecosystem-level effects were submitted, despite being highlighted as a priority for publication. The 17 papers in this issue, from Australia, Canada, the Netherlands, and USA, all deal to some extent with either population or community-level effects of roads and traffic. Nevertheless, many higher order effects remain unquantified, and must become the focus of future studies because the complexity and interactions among the effects of roads and traffic are large and potentially unexpected. An analysis of these complex interrelations requires systematic research, and it is necessary to further establish collaborative links between ecologists and transportation agencies. Many road agencies have “environmental sustainability” as one of their goals and the only way to achieve such goals is for them to support and foster long-term and credible scientific research. The current situation, with numerous small-scale projects being undertaken independently of each other, cannot provide the information required to quantify and mitigate the negative effects of roads and traffic on higher levels. The future of road ecology research will be best enhanced when multiple road projects in different states or countries are combined and studied as part of integrated, well-replicated research projects

The impact of Dutch works councils according to managers

Although works councils have, by and large, equally extensive legal rights in Germany and the Netherlands, this is the first econometric analysis that investigates the influence of Dutch works councils on firm performance. We use a nation-wide Dutch dataset with information on management’s perceptions of the works council’s impact on their firms’ efficiency and innovation. Inspired by the German study of Jirjahn and Smith (2006), we analyze which determinants influence management’s attitude toward employee participation in the Netherlands. We establish a preponderant influence emanating from the works council’s role attitude and management’s leadership style.works councils, managerial response, effectiveness, efficiency, innovation

Richtlijnen voor het meten van het gebruik van faunapassages

Faunapassages zijn een veelgebruikt middel om de barrièrewerking van wegen en spoorwegen op te heffen en het aantal aanrijdingen met dieren te beperken. De vraag is nu: Hoe komen we te weten of deze voorzieningen werken