Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
37,478
result(s) for
"cage"
Sort by:
Study on Cage Wear of Railway Traction Motor Bearings Based on Analysis of Rolling Element Motion
Cylindrical roller bearings used in traction motors for railway vehicles are used at high rotational speeds and under light loads. Under these operating conditions, the life due to cage wear is much shorter than the life due to raceway fatigue. Therefore, bearing life can be extended by reducing cage wear. The authors thought that to reduce cage wear, it is necessary to establish a dynamic analysis method for the contact between the roller and the cage, and to identify the wear mode of the cage. If cage wear follows Archard’s equation, then cage wear is proportional to the impulse caused by the contact between the rollers and the cage. Therefore, in this paper, a simple model consisting only of a roller and a cage was constructed, and the impulse was obtained via dynamic analysis. The impulses calculated by the dynamic analysis were in good agreement with those measured. In addition, the experiments showed that cage wear is proportional to the impulse and revealed the wear mode of the cage. These allow the method proposed in this paper to be used to predict cage wear and to determine bearing specifications to reduce cage wear.
Journal Article
Birds
Tweet! Tweet! Birds make fun pets. Some are small and some are tall; some are colorful and some have crests. Young readers will learn about the appearance, behavior, and abilities of pet birds, and discover why these feathered friends make amazing pets.
Book
Assembly of silver Trigons into a buckyball-like Ag180 nanocage
Buckminsterfullerene (C60) represents a perfect combination of geometry and molecular structural chemistry. It has inspired many creative ideas for building fullerene-like nanopolyhedra. These include other fullerenes, virus capsids, polyhedra based on DNA, and synthetic polynuclear metal clusters and cages. Indeed, the regular organization of large numbers of metal atoms into one highly complex structure remains one of the foremost challenges in supramolecular chemistry. Here we describe the design, synthesis, and characterization of a Ag180 nanocage with 180 Ag atoms as 4-valent vertices (V), 360 edges (E), and 182 faces (F)––sixty 3-gons, ninety 4-gons, twelve 5-gons, and twenty 6-gons––in agreement with Euler’s rule V − E + F = 2. If each 3-gon (or silver Trigon) were replaced with a carbon atom linked by edges along the 4-gons, the result would be like C60, topologically a truncated icosahedron, an Archimedean solid with icosahedral (I
h) point-group symmetry. If C60 can be described mathematically as a curling up of a 6.6.6 Platonic tiling, the Ag180 cage can be described as a curling up of a 3.4.6.4 Archimedean tiling. High-resolution electrospray ionization mass spectrometry reveals that {Ag₃}n subunits coexist with the Ag180 species in the assembly system before the final crystallization of Ag180, suggesting that the silver Trigon is the smallest building block in assembly of the final cage. Thus, we assign the underlying growth mechanism of Ag180 to the Silver-Trigon Assembly Road (STAR), an assembly path that might be further employed to fabricate larger, elegant silver cages.
Journal Article
Bi-Symmetric Polyhedral Cages with Three, Four, Five or Six Connected Faces and Small Holes
Polyhedral cages (p-cages) are Euclidean geometric structures corresponding to polyhedra with holes. They are a good example of the geometry of some artificial protein cages. In this paper we identify p-cages made out of two families of equivalent polygonal faces, where the face of one family is attached to three other faces while the faces of the other family are attached to three, four, five or six other faces. To restrict ourselves to p-cages with small holes, we consider p-cages where each hole comprises at most four faces. The construction starts from planar graphs made out of two families of equivalent nodes. One can then construct the dual of the solid corresponding to that graph and tile its faces with regular or nearly regular polygons. An energy function is then defined to quantify the amount of irregularity of the p-cages which is then minimised using a simulated annealing algorithm. We have analysed nearly 100,000 possible configurations, ruling out the p-cages made out of faces with deformations exceeding 10%. We then present graphically some of the most interesting geometries.
Journal Article
Birds
\"This search-and-find book invites early readers to look for new vocabulary words and pictures while giving simple facts about caring for a pet bird and bird behaviors\"-- Provided by publisher.
Book
Barely porous organic cages for hydrogen isotope separation
The separation of hydrogen isotopes for applications such as nuclear fusion is a major challenge. Current technologies are energy intensive and inefficient. Nanoporous materials have the potential to separate hydrogen isotopes by kinetic quantum sieving, but high separation selectivity tends to correlate with low adsorption capacity, which can prohibit process scale-up. In this study, we use organic synthesis to modify the internal cavities of cage molecules to produce hybrid materials that are excellent quantum sieves. By combining small-pore and large-pore cages together in a single solid, we produce a material with optimal separation performance that combines an excellent deuterium/hydrogen selectivity (8.0) with a high deuterium uptake (4.7 millimoles per gram).
Journal Article
No such thing as silence : John Cage's 4'33''
First performed at the midpoint of the 20th century, John Cage's '4'33\"', a composition conceived of without a single note, is among the most celebrated and ballyhooed cultural gestures in the history of modern music. This book explains '4'33\"' as a unique moment in American culture and musical composition.
Book
Bi-Symmetric Polyhedral Cages with Maximally Connected Faces and Small Holes
Polyhedral cages (p-cages) describe the geometry of some families of artificial protein cages. We identify the p-cages made out of families of equivalent polygonal faces such that the faces of one family have five neighbors and P1 edges, while those of the other family have six neighbors and P2 edges. We restrict ourselves to polyhedral cages where the holes are adjacent to four faces at most. We characterize all p-cages with a deformation of the faces, compared to regular polygons, not exceeding 10%.
Journal Article