Fast Determination of Soil Behavior in the Capillary Zone Using Simple Laboratory Tests

INE/AUTC 13.1

Using a bio-inspired model to understand the evolution of the remora adhesive disk

Manmade adhesives often fail on wet, compliant surfaces, which can result in poor performance when attaching sensors in medical, defense, and research situations. However, a number of fishes have evolved adhesive discs that allow adhesion to surfaces under challenging wetted conditions. A remarkable evolutionary advancement is found in the family of echenidae, colloquially known as the remora. In particular, the remora fishes have the ability to attach to wet, compliant bodies under high shear conditions for extended periods of time. This research addresses the lack of underwater adhesives by using remora adhesion as a bioinspired model. Evolution has taken part on this family of species, allowing them to have a biologically advanced suction cup (adhesive disk), which is dorsally located. This adhesive disk includes a complex and integrated bone and muscle structure that enhances the adhesion of the remora on rough surfaces. Manmade adhesives often fail on wet, compliant surfaces, which can result in poor performance when attaching sensors in medical, defense, and research situations. However, a number of fishes have evolved adhesive discs that allow adhesion to surfaces under challenging wetted conditions. A remarkable evolutionary advancement is found in the family of echenidae, colloquially known as the remora. In particular, the remora fishes have the ability to attach to wet, compliant bodies under high shear conditions for extended periods of time. This research addresses the lack of underwater adhesives by using remora adhesion as a bioinspired model. Evolution has taken part on this family of species, allowing them to have a biologically advanced suction cup (adhesive disk), which is dorsally located. This adhesive disk includes a complex and integrated bone and muscle structure that enhances the adhesion of the remora on rough surfaces

Design and development of wall climbing robot

This research work presents the design of a robot capable of climbing vertical and rough planes, such as stucco walls. Such a capacity offers imperative non military person and military preferences, for example, observation, perception, look and recover and actually for diversion and amusements. The robot's locomotion is performed using rack and pinion mechanism and adhesion to wall is performed by sticking using suction cups. The detailed design is modelled and fabrication is performed. It utilizes two legs, each with two degrees of freedom. And a central box containing the required mechanisms to perform the locomotion and adhesion is designed to carry any device to perform works on wall. A model of the robot is fabricated in a workshop using general tools. This model show how the mechanisms in the robot will work and how they are assembled together

NASA patent abstracts bibliography: A continuing bibliography. Section 1: Abstracts (supplement 34)

Abstracts are provided for 124 patents and patent applications entered into the NASA scientific and technical information systems during the period July 1988 through December 1988. Each entry consists of a citation, an abstract, and in most cases, a key illustration selected from the patent or patent application

Bioinspired materials for underwater adhesion with pathways to switchability

Strong adherence to underwater or wet surfaces for applications like tissue adhesion and underwater robotics is a significant challenge. This is especially apparent when switchable adhesion is required that demands rapid attachment, high adhesive capacity, and easy release. Nature displays a spectrum of permanent to reversible attachment from organisms ranging from the mussel to the octopus, providing inspiration for underwater adhesion design that has yet to be fully leveraged in synthetic systems. Here, we review the challenges and opportunities for creating underwater adhesives with a pathway to switchability. We discuss key material, geometric, modeling, and design tools necessary to achieve underwater adhesion similar to the adhesion control demonstrated in nature. Through these interdisciplinary efforts, we envision that bioinspired adhesives can rise to or even surpass the extraordinary capabilities found in biological systems

Aerodynamic measurements on a small HAWT rotor in axial and yawed flow

Current wind turbine performance codes are not yet able to predict the rotor aerodynamic behaviour with sufficient certainty. This has led to both the over-design of blades and to operational restrictions in certain wind conditions. Essentially the problem is one of aerodynamic stall. Steady 3-dimensional stall can occur near the blade root in high wind conditions and may produce more power than predicted. Dynamic stall can also be expected due to the effects of yawed operation, turbulence, tower shadow and the earth's boundary layer. The main aim of this work is to provide a coherent set of measured aerodynamic data accounting for both axial/non-axial flow and stall in high winds. These measurements are designed to highlight the effects of both steady and dynamic stall on the rotor aerodynamic performance. In addition, the data will enable current performance prediction codes to be developed and validated. A completely new turbine has been designed and built at Cranfield to make aerodynamic measurements using pressure transducers. The design has been dominated by the requirements of accommodating the transducer signal processing equipment and allowing variation of many of the rotor parameters. Three commercial glass fibre blades were installed and performance curves measured on a conventional field site at a height of 11.5m for three rotor speed settings. These measurements show the turbine to give adequate power performance. A mobile trailer has been used to tow the turbine at a height of 4m along the Cranfield runways. Mobile testing facilitates an accelerated test schedule and allows aerodynamic data to be acquired under controlled wind conditions. A fully instrumented blade, fitted with forty transducers, has been tested under these circumstances and produced a large database of pressure measurements covering operation in winds up to 25 iq/s and yaw angles between -4511 and +55°. Analysis of the data has shown it to be of good quality and allowed some of the effects of yaw and stall to be identified. The use of the data base for performance prediction code validation has also been established

Conveyor tracking using adept robot with vision guidance system

This thesis examines the integration of the robotic assembly workcell and the capability of the AdeptOne SCARA robot in performing both non-vision and vision based conveyor tracking. An experiment is set up for a Plastic Leadless Chip Carrier, or PLCC, chip and socket assembly operation. A PLCC chip is a square-shape integrated circuit that has its pins bent down around its perimeter to prevent damage to the pins during assembly and transportation. Binary image processing is employed by the vision system to recognize the random locations of incoming PLCC chips at the upstream location of the conveyor. When at least one PLCC chip is identified, the robot will acquire the chip using a special designed end effector and will wait until a printed circuit board passes the sensor at the downstream location of the conveyor. The robot will then insert the PLCC chip into the PLCC socket on the moving circuit board which is transported into the robot\u27s work envelope by the conveyor. The circuit board is fixed on the conveyor belt. The entire operation is conducted without any interruption of the conveyor\u27s motion. This thesis covers the design of the robot workcell and the end effector that accomplishes the assembly task and the results of non-vision and vision conveyor tracking during PLCC assembly using the Adept robot system

Monitoring of a full-scale embankment experiment regarding soil–vegetation–atmosphere interactions

Slope mass-wasting like shallow slides are mostly triggered by climate effects, such as rainfall, and soil–vegetation–atmosphere (SVA) interactions play a key role. SVA interactions are studied by a full-scale embankment with different orientations (North and South) and vegetation covers (bare and vegetated) in the framework of the prediction of climate change effects on slope stability in the Pyrenees. A clayey sand from the Llobregat river delta was used for the construction of the embankment and laboratory tests showed the importance of suction on the strength and hydraulic conductivity. Sixty sensors, which are mostly installed at the upper soil layer of the embankment, registered 122 variables at four vertical profiles and the meteorological station with a 5 min scan rate. Regarding temperature, daily temperature fluctuation at the shallow soil layer disappeared at a depth of about 0.5 m. There was great influence of orientation with much higher values at the South-facing slope (up to 55 °C at -1 cm depth) due to solar radiation. Regarding rainfall infiltration, only long duration rainfalls produced an important increase of soil moisture and pore water pressure, while short duration rainfalls did not trigger significant variations. However, these changes mostly affected the surface soil layer and decreased with depth.Peer ReviewedPostprint (published version

Solar heating and cooling demonstration project at the Florida solar energy center

The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. The system was designed to supply approximately 70 percent of the annual cooling and 100 percent of the heating load. The project provides unique high temperature, nonimaging, nontracking, evacuated tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection. Information is provided on the system's acceptance test results operation, controls, hardware and installation, including detailed drawings

Agricultural Structures and Mechanization

In our globalized world, the need to produce quality and safe food has increased exponentially in recent decades to meet the growing demands of the world population. This expectation is being met by acting at multiple levels, but mainly through the introduction of new technologies in the agricultural and agri-food sectors. In this context, agricultural, livestock, agro-industrial buildings, and agrarian infrastructure are being built on the basis of a sophisticated design that integrates environmental, landscape, and occupational safety, new construction materials, new facilities, and mechanization with state-of-the-art automatic systems, using calculation models and computer programs. It is necessary to promote research and dissemination of results in the field of mechanization and agricultural structures, specifically with regard to farm building and rural landscape, land and water use and environment, power and machinery, information systems and precision farming, processing and post-harvest technology and logistics, energy and non-food production technology, systems engineering and management, and fruit and vegetable cultivation systems. This Special Issue focuses on the role that mechanization and agricultural structures play in the production of high-quality food and continuously over time. For this reason, it publishes highly interdisciplinary quality studies from disparate research fields including agriculture, engineering design, calculation and modeling, landscaping, environmentalism, and even ergonomics and occupational risk prevention