Flutter suppression by active control and its benefits

A general discussion of the airplane applications of active flutter suppression systems is presented with focus on supersonic cruise aircraft configurations. Topics addressed include a brief historical review; benefits, risks, and concerns; methods of application; and applicable configurations. Results are presented where the direct operating costs and performance benefits of an arrow wing supersonic cruise vehicle equipped with an active flutter suppression system are compared with corresponding costs and performance of the same baseline airplane where the flutter deficiency was corrected by passive methods (increases in structural stiffness). The design, synthesis, and conceptual mechanization of the active flutter suppression system are discussed. The results show that a substantial weight savings can be accomplished by using the active system. For the same payload and range, airplane direct operating costs are reduced by using the active system. The results also indicate that the weight savings translates into increased range or payload

Art399 Portfolio

When I was young I wasn\u27t much into art. I liked doing my owns thing and looking at cool images and colors that grabbed my attention, now really understanding that I actually liked art. The way I really knew how to communicate my feelings was to draw them out since I struggled verbally expressing them. I really didn\u27t know exactly what I was doing but I was drawing or doing other creative ways to express the way I was feeling at the moment to others. Sometimes to this day I still do that but I\u27m at lot better at expressing my emotions on paper through graphite or charcoal and painting. My art is about feelings, thoughts that can’t be expressed aloud. I wanna make art so that my audience can understand the way I come up with my pieces. The places in the art are significant to me, they are somewhere I’ve been, and to me felt right to create a piece of art from. In my piece Through My Lense, the background is a place that I’ve been to and it has been a special memory and place that I had to make a piece out of. The value of contrast helps elevate the understanding of depth, space, giving it a more authentic look. Listening to music, being in my own space with my thoughts is the main drive for me to do art. Having the right music and beat that I can get in the zone with helps me focus, giving the artwork the accuracy I wanted. Most of the artwork I make doesn’t have color because to me it seems more real, also shows my improvement with tones of contrast along with my attention to detail. Some of the artworks that have color to show my range of color value and blends, making the art piece pop and capture the eye of the audience. Toyin Ojih’s portraits capture people in the middle of an activity or about to finish that action. Toyin captures the image of black people and tries to fight against the bad depictions that other people wanna see. I practice art in my own space while experimenting with some different techniques I’ve learned or noticed while observing others\u27 artwork and listening to how they went about doing, trying new things. Like painting, I picked some new methods and techniques on how to start and where to execute the process of going about making a portrait or landscape painting.https://digitalcommons.murraystate.edu/art399/1151/thumbnail.jp

Thiocyanate complexes of osmium

Osmium is a hard grey brittle metal which scratches glass. It has a melting point of 2700[degree]C, and a specific gravity of 22.4, which is greater than any other known substance. The grey color of osmium resembles the grey color of iron and ruthenium. Osmium was discovered in 1803 by Tennant in the insoluble residue remaining after treating an alloy of the platinum metals with acid. Osmium occurs in nature alloyed with the other metals of the platinum group. One type of alloy includes all six of the of the platinum metals, osmium, iridium, platinum, ruthernium, rhodium and palladium. Osmium also occurs in an alloy of osmium and iridium called osmiridium. These alloys are usually recovered by placer mining methods. Canada, Russia, Colombia, South Africa and the United States are the worlds producers of platinum metals. The beds of Alaskan rivers contain platinum metals. Osmium has limited uses due in part to scarcity. Its cost is approximately fifty dollars per ounce. Haber found that osmium metal catalyzes the synthesis of ammonia from the elements. Other investigators have ranked osmium first in catalytic powers among the platinum metals. Osmium alloys are used for bearings in place of jewels in precision instruments because of their resistance to wear. Osmium alloys are also used in pen points because of their resistance to wear and corrosion Osmium tetroxide finds use as a catalyst in inorganic and organic reactions. It is employed as a catalyst in the quantitative determination of arsenic in which arsenite is titrated with ceric sulfate. Osmium tetroxide catalyzes the action of potassium permanganate on maleic acid to form meso-tartaric acid; and also catalyzes the additions of hydrogen peroxide to other ethelenic compounds to form glycols. Osmium tetroxide is used to develop fresh glycols. Osmium tetroxide is used to develop fresh finger prints. It also finds use as a hardening and staining agent in making sections for study under the microscope in biological work. Many problems were encountered in attacking the structure of the osmium thiocyanate complex. Preliminary investigations showed that the red complex could be prepared by the direct action of osmium tetroxide on solutions of sodium thiocyanate in perchloric acid. Complex colors developed in great excess of thiocyanate showed no fading over a period of a week. The complex was found to follow Beers law (See figure 1). Sulfate ions appeared as a by product of the reaction, indicating a reduction of the osmium to a lower oxidation state. The speed of the reaction appeared to be dependent on on CNS concentration. At high CNS concentrations, good colors were developed, but at lower concentrations the colors were obscured by the appearance of a dark precipitate of a colloidal nature

Influence of correlated visual cues on auditory signal detection

Influence of correlated visual cues on auditory signal detectio

Off-Campus Instruction Via Video Tape

The Continuing Education Via Video Tape Program presents Iowa State University graduate and advanced undergraduate courses to off-campus people at or near their place of employment solely by means of video tapes. Course offerings are primarily in engineering; some non-engineering courses have been and will be taped and shown

Genetic endangerment of wild Red Junglefowl *Gallus gallus*?

Domestic chickens were derived from the wild Red Junglefowl Gallus gallus. A survey of 745 museum specimens of Red Junglefowl suggests that most wild populations have been contaminated genetically by introgression of genes from domestic or feral chickens. A male eclipse plumage, which appears to be an indicator of pure wild genotypes, was found in populations in the western and central portions of the species's range, but not in the easternmost populations. Eclipse plumages probably disappeared from extreme south-eastern Asia and the Philippines prior to the advent of intensive scientific collecting (about i860) and have not been observed in Malaysia and neighbouring countries since the 1920s. Populations exhibiting eclipse plumages were found in north-eastern India as late as the 1960s, but the dense human populations there make their continuing genetic integrity uncertain. These data suggest that surveys of wild and captive populations should be undertaken to assess the genetic integrity of this species. A re-evaluation of the conservation status of Red Junglefowl might then follow

A Note on Embedding of M-Theory Corrections into Eleven-Dimensional Superspace

By analyzing eleven-dimensional superspace fourth-rank superfield strength F-Bianchi identities, we show that M-theory corrections to eleven-dimensional supergravity can not be embedded into the mass dimension zero constraints, such as the (\g^{a b})_{\a\b} X_{a b}{}^c or i (\g^{a_1... a_5})_{\a\b} X_{a_1... a_5}{}^c -terms in the supertorsion constraint T_{\a\b}{}^c. The only possible modification of superspace constraint at dimension zero is found to be the scaling of F_{\a\b c d} like F_{\a\b c d} = (1/2) \big(\g_{c d}\big)_{\a\b} e^\Phi for some real scalar superfield \Phi, which alone is further shown not enough to embed general M-theory corrections. This conclusion is based on the dimension zero F-Bianchi identity under the two assumptions: (i) There are no negative dimensional constraints on the F-superfield strength: F_{\a\b\g\d} = F_{\a\b\g d} =0; (ii) The supertorsion T-Bianchi identities and F-Bianchi identities are not modified by Chern-Simons terms. Our result can serve as a powerful tool for future exploration of M-theory corrections embedded into eleven-dimensional superspace supergravity.Comment: 14 pages, latex, some minor typos corrected, as well as old section 5 deleted, due to the subtlety about Chern-Simons term in F-Bianchi identitie

Tribology: The Story of Lubrication and Wear

Topics addressed include: lubrication and design of high speed rolling element bearings, high speed gears, and traction drives