814 research outputs found
Evaluation of two designs for cryogenic insulation
Shingle-type, crinkled, aluminized polyethylene ester is thermally and structurally tested for cryogenic insulation. Insulation systems require thermal efficiency with minimum weight, and the ability to withstand vibration, acceleration, and rapid pressure drops
New Audiovisual Methods in Veterinary Medical Education
In the years 1953-1954 and 1954-55, the veterinary students afforded us the opportunity to discuss Recent developments in veterinary anatomy at Iowa State College as well as Visual aids and their application to the teaching of veterinary medicine . I am indeed honored and pleased to again be given the opportunity, not only to review the progress made to date, but also to project, into the foreseeable future, our thoughts relative to the role of the multi-media approach to veterinary education
Megapezia longipes Willard and Cleaves 1930 from the Pennsylvanian Rhode Island Formation of Massachusetts: ichnotaxonomic status
The type and only specimen of the ichnospecies Megapezia longipes, from the Pennsylvanian Rhode Island Forma-tion of Plainville, Massachusetts, consists of two poorly defined tracks, one made by a manus and the other by a pes, rather than a single pedal imprint. Whereas the type species of Megapezia, Megapezia pineoi, has tetradactyl pedal imprints, the pes imprint of Megapezia longipes is pentadactyl, a feature that precludes assignment to this ichnogenus. Rather, the tracks share two characteristics with the ichnogenus Matthewichnus, namely elongate digits II and III on the manus, and a pes imprint oriented anterolaterally to the manus imprint, and are thus tentatively reassigned to that ichnogenus. Cf. Matthewichnus longipes is retained as a separate ichnospecies pending the collection of additional ma-terial that can be compared with other species within the ichnogenus. With the tentative reassignment of the Plainville tracks to Matthewichnus, Megapezia becomes monospecific and is no longer recorded in New England. The tracks are the first known occurrence of Matthewichnus from this region
Recent Developments in Veterinary Anatomy at Iowa State College
A check on figures reveals that the credit hours in gross anatomy have been gradually reduced from 27 credit hours in 1930 to 15 credit hours in 1952. Histology, which was listed as 4 credits in 1930, has increased to 14 credits in 1952. These figures compare favorably with the credit hours offered in the various anatomy departments throughout the country today. Dr. Merchant (Dean of Veterinary Medicine at Iowa State College) and the Curriculum Committee made a rather thorough study a few years ago of the credit hours allocated to all the subjects in the four professional years in the various veterinary institutions. This figure is also within the 15 to 17 per cent clock-hours recommendation of the A.V.M.A. Council on Education as listed in the 1952 directory. However, we must admit we cannot hope to cover as completely the anatomy of the horse in one quarter when formerly two years were devoted to its study
Visual Aids and Their Application To the Teaching of Veterinary Medicine
Within the past two decades, the scope of veterinary anatomy instruction has been broadened to include not only the detailed study of the horse, but also that of each of the domesticated animals as well. However, the over-all trend throughout the country has been to decrease the allotted time for dissection. This has resulted in a wide discrepancy between the vast amount of material that each student is expected to master and the time which is allotted him to accomplish this feat. Today, we are attempting to teach the anatomy of more than half a dozen animals in less time than was formerly allotted to the horse alone
Farm Uses for Native Lumber
Portions of the lumber from native Iowa woodlands go into many different uses-both industrial and on the farm. But most of the lumber is used right on the farm where it grows, for construction, repair work and fuel
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Paleobiology of the Climactichnites Trackmaker: An Enigmatic Late Cambrian Animal Known Only from Trace Fossils
Based on a thorough examination of museum and field Climactichnites specimens, two species of this trace, which is restricted to North America, are recognized, each representing a unique behavioral variant. C. wilsoni represents surface-produced trackways, whereas C. youngi is re-erected for subsurface burrows. Burrowing behavior is supported by the presence of C. youngi within beds, the orientation of burrows inclined to bedding, and the presence of distinct burrow fills. Burrows are distinguished from surface traces by characteristics including the absence of lateral ridges and the presence of mm-sized striations superimposed on the trace. Burrowing behavior was previously unknown and represents a new behavior for the animal. A new ichnospecies, Musculopodus sedentarius, is erected for sedentary impressions of the animal. In the future Musculopodus may be expanded to include the resting traces of other soft-bodied animals known from fossils.
Analysis of Climactichnites indicates that the trackmaker was elongate, bilaterally symmetric, dorsoventrally flattened, and soft-footed. These characteristics are consistent with the trackmaker being a primitive mollusk or mollusk-like animal. Unlike other Neoproterozoic and Cambrain mollusks, such as Matthevia, Wiwaxia, and Odontogriphus, the Climactichnites trackmaker could reach considerable size. At up to 29 cm wide and possibly 67 cm long, it was one of the largest animals of its time.
During locomotion, the animal generated muscular waves along the sole of its foot, which was extended and clamped into the substrate. Contraction of pedal muscles then pulled the body forward. This method of locomotion is similar to that employed by some gastropods, including Bullia and Polinices, which make Climactichnites-like trackways in exposed intertidal settings today. However, these modern trackways are not preserved because they are eroded by wind, waves, tides and subsequent bioturbation, as experiments confirm. Abundant microbial sedimentary structures associated with Cambrian occurrences suggests that microbial binding may have mediated the preservation of Climactichnites.
Two lines of evidence suggest that the Climactichnites trackmaker may have been one of the first animals to venture onto land: the co-occurrence of subaerially-produced sedimentary structures, such as adhesion structures and raindrop impressions, and trackways that span shoreline depth gradients and exhibit variable preservation quality along their length
Frequency multiplication in high-energy electron beams Semiannual progress report, 1 Apr. - 1 Oct. 1967
High energy electron beam studies dealing with nonlinear analysis of beam-plasma interactions, cyclotron harmonic instabilities, and frequency multiplicatio
Microwave device investigations Semiannual progress report, 1 Oct. 1969 - 1 Apr. 1970
Beam-plasma interactions, cyclotron harmonic instability study, and millimeter and submillimeter wave detection by paramagnetic material
Semiquantitative Infrared Analysis of Diketones and Anhydrides in a Reaction Mixture
The ozonolysis of a hydroxymethylene ketone yields a mixture of diketone and anhydride. Treatment of hydroxymethylene camphor with ozone affords, in addition to the expected camphor quinone, a surprisingly large amount of camphoric anhydride (56%) via Baeyer-Villager reaction. Use of infrared absorption to analyze the relative amounts of camphor quinone and camphoric anhydride in a reaction mixture was studied by comparing peak heights of their carbonyl stretching bands
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