Tribophyiscal scaling effects in friction and wear of polymers on small- and large-scale tests

Tribotest ◽  
10.1002/tt.60 ◽  
2008 ◽  
Vol 14 (4) ◽  
pp. 207-224
Author(s):  
P. Samyn ◽  
G. Schoukens
Keyword(s):  
Friction And Wear ◽  
Large Scale ◽  
Scaling Effects ◽  
Large Scale Tests

SYNTHETIC PHEROMONES DISRUPT MALE DIORYCTRIA SPP. MOTHS IN A LOBLOLLY PINE SEED ORCHARD

2000 ◽  
Vol 132 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Gary L. DeBarr ◽  
James L. Hanula ◽  
Christine G. Niwa ◽  
John C. Nord
Keyword(s):  
Loblolly Pine ◽  
Large Scale ◽  
Sex Pheromones ◽  
Mating Disruption ◽  
Seed Orchard ◽  
Control Treatment ◽  
Tetradecenyl Acetate ◽  
Lepidoptera Pyralidae ◽  
Trap Catches ◽  
Large Scale Tests

AbstractSynthetic sex pheromones released in a loblolly pine, Pinus taeda L. (Pinaceae), seed orchard interfered with the ability of male coneworm moths, Dioryctria Zeller spp. (Lepidoptera: Pyralidae), to locate traps baited with sex pheromones or live females. Pherocon 1C® traps baited with synthetic pheromones or live conspecific females were hung near the center of two 1.2-ha circular plots during emergence of Dioryctria amatella (Hulst), Dioryctria disclusa (Heinrich), and Dioryctria merkeli (Mutuura and Munroe). In a paired design, trap catches for the mating-disruption treatment with synthetic pheromone dispensers consisting of three polyvinyl chloride rods placed in every tree were compared with the control treatment. Treatments were alternated at intervals of 2–3 d. Trap catches of D. amatella were reduced by 91% when plots were treated with 2.5 g/ha of Z-11-hexadencenyl acetate. Catches were reduced by 99.5% for D. disclusa and by 97% for D. merkeli when plots were treated with 12.5 g/ha of Z-9-tetradecenyl acetate, whereas catches of D. amatella were unaffected by this mating-disruption treatment. Daily disappearance of Z-9-tetradecenyl acetate from the dispensers averaged 0.46 g/ha or less. Manually placing dispensers on nylon lines in the tops of trees was an effective method for releasing synthetic Dioryctria pheromones in the orchard. These data suggest it may be feasible to prevent mating of Dioryctria spp. in pine seed orchards by using synthetic pheromones for mating disruption, but large-scale tests will be required to demonstrate cone protection.

scholarly journals Seismic Behavior and Force-Displacement Characterization of Neotype Column-Slab High Piers

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
YanQun Zhou ◽  
YeZhi Zhang ◽  
MeiXin Ye ◽  
MengSi Zhan
Keyword(s):  
Seismic Behavior ◽  
Large Scale ◽  
Scale Model ◽  
Test Results ◽  
Lateral Displacements ◽  
High Pier ◽  
Experimental Values ◽  
Large Scale Tests ◽  
Force Displacement

The seismic behavior and plasticity spreading of a neotype column-slab high pier are researched in this paper. Four scale model tests of a web slab with two boundary columns are carried out under cyclic inelastic lateral displacements simulating seismic response. The test results show that the neotype column-slab high pier has strong and stable bearing capacity, good ductility, and energy dissipation capacity. The experimental values pertaining to the spread of plasticity are derived. An approach for deriving the spread of plasticity analytically is deduced and applied to the four tests. This method accurately assesses a pier’s spread of plasticity for most ductility levels. At nearly all ductility levels, the mean difference between analytical assessments of the spread of plasticity and results from 4 large-scale tests is 12% with a 9% coefficient of variation.

scholarly journals Evaluation of Various Perimeter Barrier Products

2021 ◽  
Author(s):  
Rabin Bhattarai ◽  
◽  
Yufan Zhang ◽  
Jacob Wood ◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Sediment Concentration ◽  
Department Of Transportation ◽  
Vegetative Cover ◽  
Buffer Strip ◽  
Erosion Rates ◽  
Sediment Removal ◽  
Loam Soil ◽  
A Site ◽  
Large Scale Tests

Construction activities entail substantial disturbance of topsoil and vegetative cover. As a result, stormwater runoff and erosion rates are increased significantly. If the soil erosion and subsequently generated sediment are not contained within the site, they would have a negative off-site impact as well as a detrimental influence on the receiving water body. In this study, replicable large-scale tests were used to analyze the ability of products to prevent sediment from exiting the perimeter of a site via sheet flow. The goal of these tests was to compare products to examine how well they retain sediment and how much ponding occurs upstream, as well as other criteria of interest to the Illinois Department of Transportation. The products analyzed were silt fence, woven monofilament geotextile, Filtrexx Siltsoxx, ERTEC ProWattle, triangular silt dike, sediment log, coconut coir log, Siltworm, GeoRidge, straw wattles, and Terra-Tube. Joint tests and vegetated buffer strip tests were also conducted. The duration of each test was 30 minutes, and 116 pounds of clay-loam soil were mixed with water in a 300 gallon tank. The solution was continuously mixed throughout the test. The sediment-water slurry was uniformly discharged over an 8 ft by 20 ft impervious 3:1 slope. The bottom of the slope had a permeable zone (8 ft by 8 ft) constructed from the same soil used in the mixing. The product was installed near the center of this zone. Water samples were collected at 5 minute intervals upstream and downstream of the product. These samples were analyzed for total sediment concentration to determine the effectiveness of each product. The performance of each product was evaluated in terms of sediment removal, ponding, ease of installation, and sustainability.

scholarly journals LARGE AND SMALL SCALE WAVE OVERTOPPING MEASUREMENTS FOR AFSLUITDIJK REHABILITATION PROJECT

2020 ◽  
pp. 15
Author(s):  
Wouter Ockeloen ◽  
Coen Kuiper ◽  
Sjoerd van den Steen
Keyword(s):  
Water Management ◽  
Physical Model ◽  
Large Scale ◽  
Wadden Sea ◽  
Model Tests ◽  
Small Scale ◽  
Water Safety ◽  
Wave Overtopping ◽  
Physical Model Tests ◽  
Large Scale Tests

The 'Afsluitdijk' is a 32 km enclosure dam which separates the Wadden sea and the Lake IJssel. The dam currently undergoes a major rehabilitation to meet the requirements with regard to water safety. The Dutch Ministry of infrastructure and Water Management (Rijkswaterstaat division) has commissioned Levvel, a consortium of BAM, Van Oord and Rebel, to prepare the design and carry out the reconstruction of the dam including sluices and highway. The project includes reinforcement of the armour layers and wave overtopping reduction. As part of the contract Rijkswaterstaat prescribed the contractor (Levvel) to verify the design with large scale physical model tests (min. 1:3 scale). These tests were carried out in the Delta Flume of Deltares. Prior to the large scale tests, smaller scale tests (1:20) have been carried out to optimize the design with regard to armour stability and wave overtopping. The research described here focuses on the wave overtopping.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kPga0wVCCIE

scholarly journals LOADS ON WIND TURBINES ACCESS PLATFORMS WITH GRATINGS

2011 ◽  
Vol 1 (32) ◽  
pp. 65
Author(s):  
Thomas Lykke Andersen ◽  
Peter Frigaard ◽  
Michael R Rasmussen ◽  
Luca Martinelli
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Peak Load ◽  
Multiplication Factor ◽  
Preliminary Results ◽  
Different Types ◽  
The Many ◽  
Large Scale Tests

The present paper deals with loads on wind turbine access platforms. The many planned new wind turbine parks together with the observed damages on platforms in several existing parks make the topic very important. The paper gives an overview of recently developed design formulae for different types of entrance platforms. Moreover, the paper present new results on loads on grates based on both drag coefficient measurements and preliminary results on slamming from large scale tests. As expected both investigations show that platforms with grates give a significant reduction in the loads compared to closed plate platforms. The grate multiplication factor, defined as the peak load on the grate platform relative to the peak load on a closed plate platform was found approximately equal to the solidity of the grate.

The Belgian Demonstration Programme for the Disposal of High-Level and Long-Lived Radioactive Waste

2006 ◽  
Vol 932 ◽  
Author(s):  
Bernier Frédéric ◽  
Demarche Marc ◽  
Bel Johan
Keyword(s):  
Radioactive Waste ◽  
Thermal Load ◽  
Large Scale ◽  
Mechanical Response ◽  
Boom Clay ◽  
Geological Formation ◽  
Important Input ◽  
Clay Layers ◽  
High Level ◽  
Large Scale Tests

ABSTRACTThe EIG EURIDICE is responsible for performing large-scale tests, technical demonstrations and experiments so as to assess the feasibility of a final disposal of vitrified radioactive waste in deep clay layers. This programme is part of the Belgian Research and Development programme managed by ONDRAF/NIRAS. The research infrastructure includes the Underground Research Facilities HADES (URF HADES) in the Boom Clay geological formation and surface facilities. The achievements of the demonstration programme are the demonstration of the construction of shafts and galleries at industrial scale, the characterisation of the hydro-mechanical response of the host rock, and the “OPHELIE mock-up” a large scale hydration test under thermal load of pre-fabricated bentonite blocks. The future works will consist mainly in the realisation of the “PRACLAY experiments” including a large scale heater test. The large scale heater test has to demonstrate that Boom Clay is suitable, in terms of performance of the disposal system, to undergo the thermal load induced by the vitrified waste. The combined effect of the excavation and the thermal load will be investigated. A long term (more than 10 years) large scale heater test would be representative of the most penalizing conditions that could be encountered in the real disposal. The results of this test will constitute an important input for the Safety and Feasibility Cases 1 (SFC-1, 2013) and 2 (SFC-2, 2020).

Friction and wear of diamond and diamond-like carbon films

2002 ◽  
Vol 216 (6) ◽  
pp. 387-400 ◽  
Author(s):  
A Erdemir
Keyword(s):  
Wear Mechanisms ◽  
Friction And Wear ◽  
Large Scale ◽  
Microelectromechanical Systems ◽  
Elevated Temperatures ◽  
Diamond Like Carbon ◽  
Mechanical Seals ◽  
Wear Properties ◽  
Specific Test ◽  
Wide Range

Detailed tribological studies on diamond and diamond-like carbon (DLC) films have confirmed that these films are inherently self-lubricating and resistant to abrasive, adhesive and corrosive wear. Because of their high chemical inertness, they are also resistant to corrosion and oxidation (even at elevated temperatures). The combination of such exceptional qualities in these films makes them ideal for a wide range of demanding tribological applications (such as microelectromechanical systems, cutting tools, mechanical seals, magnetic hard disks, etc.). These films, available for more than three decades, have been used extensively for tooling and magnetic hard disk applications. Their potential in other application areas is currently being explored around the world. With the development of new and more robust deposition methods in recent years, it is envisioned that the production of high quality diamond and DLC films will become very cost effective and highly reliable for large-scale applications in the transportation and manufacturing sectors. In this paper, sliding wear mechanisms of diamond and DLC films will be presented. Specifically, it will be shown that, in general, the wear of these films is extremely low (mainly because of their exceptional hardness and low friction characteristics). Specific test conditions established during each sliding test, however, may dramatically affect the wear performance of certain diamond and DLC films. One of the dominant wear mechanisms relates to a phase transformation that is primarily the result of very high mechanical and thermal loadings of sliding contact interfaces. The transformation products (such as disordered graphite) trapped at the sliding interface may transfer to the mating surface and significantly affect friction and wear. This paper describes, in terms of structural and fundamental tribological knowledge, the ideal film microstructures and chemistry, as well as operational conditions under which diamond and DLC films perform the best and provide superlow friction and wear properties in sliding tribological applications.

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