Shiny Metal Research Articles

Effect of hydrogen-switchable mirrors on the Casimir force.

We present systematic measurements of the Casimir force between a gold-coated plate and a sphere coated with a hydrogen-switchable mirror. Hydrogen-switchable mirrors are shiny metals that can become transparent upon hydrogenation. Despite such a dramatic change of the optical properties of the sphere, we did not observe any significant decrease of the Casimir force after filling the experimental apparatus with hydrogen. This counterintuitive result can be explained by the Lifshitz theory that describes the Casimir attraction between metallic and dielectric materials.

String crossings [computer graphics

When the author was about 10 years old, he completed a project which involved driving little brass nails into a piece of wood so that they were equally spaced around a circle, and then winding shiny metal wire between every pair of nails. The result was a shiny spider's web of wire-it was an algorithm for making an aesthetic visual piece. Years later, when he started to learn computer graphics, he programmed up these string art creations on vector storage tubes and plotters, mixing colors and changing line widths. Then recently, an artist friend (Dan Robbins) mentioned that he was planning a sculpture that involved a similar kind of design. Part of his sculpture involved placing objects at the intersections of pairs of strings. He wanted to plan part of the sculpture in advance and asked if there was a way to determine how many strings were necessary to get a desired number of intersections. The article starts with an answer to Dan's question. It also explores some other questions derived from these simple but elegant little string art patterns. These lovely little geometric patterns lead to numerical patterns every bit as graceful and aesthetically pleasing.

Rapid graphitization of a pulsed laser remelted ductile cast iron during multipass overlap melting

As-cast ductile cast iron with an as-machined shiny metal surface was remelted with a high-power (1 kW) pulsed Nd:YAG laser using both single- and multipass overlap melt tracks. Changes in the microstructure of the underlying laser melted track caused by the transient overlap heating during multipass overlap remelting process were studied. The rapidly solidified metastable ledeburite structure of the underlying laser melted track was found to be rapidly graphitized during overlap remelting. The graphitized zone consists of a fully graphitized zone containing extremely fine graphite nodules and a partially graphitized zone containing extremely fine graphite nodules and undissolved cementite. The overlap ratios of the melt tracks were shown to have no noticeable influence on either the graphitized microstructure and the size of the graphitization zones. This newly observed rapid graphitization phenomenon is preliminarily discussed in terms of the microstructural characteristics of the rapidly solidified ductile iron and the unique heating behavior of pulsed laser beam to material.

If I Only Had a Brain

If I Only Had a Brain Steven Shaviro Burroughs writes: “in this life we have to take things as we find them as the torso murderer said when he discovered his victim was a quadruple amputee.” Good advice for the anatomically deranged, like Cliff Steele. He’s a character in the DC/Vertigo comic book DOOM PATROL; I refer in particular to the issues written by Grant Morrison and illustrated by Richard Case, between 1989 and 1992 (#s 19–63). Cliff has a problem with his body, you see. It happened like this. He used to be a daredevil racing car driver; he had a horrible wreck. Nearly all of him was burned to ashes, but they snatched his brain from the flames. And then they implanted that brain in a new prosthetic body, all shiny metal, ultra high tech, a veritable fighting machine. Now Cliff is the muscle of the DOOM PATROL, a brain turned into brawn. They expect him to be a macho bruiser, when actually he’s quite sensitive underneath. And to add insult to injury, they call him Robotman—a name he violently hates. What would that do for your sense of self-esteem? The life of a superhero these days! Cliff thinks of himself as just a regular guy; Robocop fantasies are the last thing on his mind. But with a metallic casing like this, he can’t exactly blend into the crowd. It’s what Baudrillard calls hyper-visibility, the postmodern condition par excellence. No chance of chilling out with a secret identity, like old Clark Kent used to do. All this metal is a clunky encumbrance, no matter how great its tensile strength. You know you’re in bad shape when you bang your head against a wall, and you still don’t feel a thing. At this point, Cliff doesn’t even really know what his body can do. How good is all this cyber-tech stuff anyway? How accurate and detailed is sensory input? How fast is motor response? What unaccustomed relays and connections now trigger the pain and pleasure centers in Cliff’s brain? Will he ever be able to taste and smell? Can he ever have sex again? What about getting drunk or stoned? “The only good thing about having a human brain in a robot body,” Cliff remarks sardonically at one point, “is that it’s easier to control brain chemistry.” Just the touch of a button, and anxiety is dissipated, alertness is heightened, or memory is enhanced. But alas, this techno-manipulation seems to work only for utilitarian ends, and not for hedonistic ones. “Our machines are disturbingly lively,” Donna Haraway writes, “and we ourselves frighteningly inert.” It might not be so bad, if only you could get used to the situation. After all, Descartes argued long ago that the body is a machine. It shouldn’t matter all that much whether metal or flesh is the medium. In either case, it’s simply a matter of mastering the electrochemical interface: regularizing chains of association, facilitating neural feedback patterns, reinforcing the appropriate re-entrant connections. In short, a question of recognition and memory, of cultivating habits over the course of time. The problem is that Cliff’s mechanical body never stays the same. He’s continually being sent back to the shop for upgrades and repairs. Transistors burn out; programming errors and faulty couplings throw him off stride. He gets into fights, and enemies regularly mangle his metal to bits. As if that weren’t bad enough, Doc Magnus (who built and programmed his body in the first place) and Niles Caulder (the Chief of the DOOM PATROL) tend to use Cliff as a pawn in their ongoing professional rivalry. Neither of them is content to let well enough alone; they are both all too eager to retool him in order to try out their latest cybernetic design ideas. And let’s not even think about those insectoid aliens who at one point fit Cliff out in a new metal carapace with six legs. Life in a robot body, even if you’re strong, is just one humiliation after another. The persistence of memory in the brain...

Inhomogeneous surfaces as selective solar absorbers

An outstanding problem facing solar thermal collectors is the development of efficient, cheap and long-lived selective solar absorbing surfaces. Among the best products currently available are complicated inhomogeneous mixtures of metal and dielectric particles optimized from serendipitous discoveries rather than premediated constructions. We have utilized a computer code which uses mean field approximations and can accurately describe the reflectance of inhomogeneous surfaces. This approach gave us the freedom to use realistic materials parameters and surface topologies and arbitrary angles of incidence in our calculations. As a result of calculations on a large number of specific surface configurations and material combinations, we found that the optical properties of such surfaces are largely independent of the details of their topologies and can be described with only two parameters: surface depth, D, and correlation length, 2 a. A main conclusion of the paper is that the impression of a rough surface on an otherwise shiny metal leads to a sharply defined low reflection window between λ II≈20 A and λ≈6 D if λ II< λ I. For λ < λ II, the reflective approaches the bulk value. For λ < λ II, the reflectivity is diffuse. The calculations provide a new insight into the operation of the currently popular selective surfaces and define a bench mark against which their performance can be evaluated.

Rural Revolution in East Carolina

T OBACCO is the nation's fifth most important cash crop, after corn, soybeans, wheat, and cotton. In 1976 the crop placed a billion dollars in the pockets of in North Carolina, and half a billion in the pockets of Kentucky farmers; it accounted for approximately half of the total farm income in each state. In that same year the United States exported almost a billion dollars' worth of tobacco leaf and almost half a billion dollars' worth of manufactured tobacco products, mainly through the ports of Norfolk, Virginia, and Wilmington, North Carolina.1 Tobacco has been one of the last major field crops in the United States to be mechanized. Even after World War II, in fact, observers still wondered whether machines could ever perform some of the delicate tasks required in producing the crop.2 Within the past quarter-century, however, the production of flue-cured tobacco (which is concentrated in Virginia, the Carolinas, and Georgia) has become increasingly mechanized, although the mechanization of the crop is still far from complete. Much hand labor still is needed in certain stages of production, and some have adopted the new techniques and equipment less enthusiastically than their neighbors. The mechanization of flue-cured tobacco production, late and spasmodic though it has been, has nevertheless wrought a rural revolution in the producing districts, where the contemporary countryside is an odd blend of the past and the future, reflecting the changes that are taking place. Tens of thousands of tired old cubeshaped flue-cured tobacco barns still dot the land, but they have been superseded by shiny new metal bulk-curing barns. Field layouts have been modified to accommodate the new machines. Farmers have been obliged to cultivate larger acreages in order to use these machines efficiently. The land available for sale or rent has been scattered at ever greater distances from their original farmsteads, and some have succumbed to the temptation to move into nearby towns and become sidewalk farmers when their former farmsteads are no longer central to their farm operations. The traditional techniques of flue-cured tobacco production required large numbers of farm workers, mostly black people, but farm mechanization has not triggered a massive out-migration of displaced farm workers. The availability of a large labor force, emacipated from the land by the new farm machines, has attracted many new factories to the tobacco districts, and eastern North Carolina has made the transition from an agricultural to a mixed economy, a transition to which so many of the lesser-

Display of sodium as a shiny metal

Involves adding a few drops of a high molecular weight secondary alcohol to delay oxidation of the sodium while stored under kerosene.

Wear of steel due to intense seizing

Dry friction of steel on steel at high pressures and sliding speeds takes place without any noticeable oxidation of the rubbing surfaces and is accompanied by intense seizing and wear. The products of wear are not oxidized and appear as shiny metal particles [1].

3. Second harmonic generation in solids: P.L. Kelley (Lincoln Laboratory, Massachusetts Institute of Technology, Lexington 73, Massachusetts, U.S.A.)

This chapter describes molybdenum and its compounds, including oxides of molybdenum, sulfides of molybdenum, other compounds of molybdenum, molybdenum compounds in lubrication, and chemical uses of molybdenum. Molybdenum is the element of atomic number 42, and its atomic weight is 95.95. It is a shiny grey metal, resembling steel in appearance, but with an unusually high melting point of 2610°C. Like all the other transition elements, molybdenum is a metal, and it is widely used as an alloying element and as a metallic coating. At least nine oxides of molybdenum are reposed, but of these the monoclinic dioxide MoO2 and the orthorhombic trioxide are the most common and most stable. Molybdenum dioxide, although less important than the trioxide, is more abrasive. The only important sulphide of molybdenum is the disulphide MoS2. Apart from the oxides and sulphides, other groups of simple compounds are the halides, chalcogenides, and molybdates, and there are a number of well characterized organic compounds. Apart from molybdenum disulphide, diselenide, and ditelluride, several molybdenum compounds are used as additives in lubricating oils and greases.

Abnormal Appetite of Laying Hens in Feeding Experiments

APPETITE or hunger may be defined primarily as sensation resulting from need for food. Appetite may be mild hunger. With the chicken it may be that hunger or appetite is in a measure associated with habit since hens after having consumed their fill of any feed are passive, but will immediately recommence eating should a new supply of the same feed be added to the partly filled trough, a frequently repeated operation. Reflected light may also play a distinct part in the urge of chickens to consume certain food, as is witnessed by the picking at a gold ring or other shiny metal brought before them. This too is shown by the fact that chickens as a rule prefer oyster shell or cystalline calcite or other shiny material to the dull nonreflecting rock limestone which serves the same purpose of supplying calcium.Experiments have shown that many chickens prefer certain .