Noise requirements from a military point of view

External and internal aircraft noise requirements are discussed in terms of application to military helicopters. The impact of the application of noise reduction technology to comply with FAA standards on cost and performance is emphasized

Sequentially deployable maneuverable tetrahedral beam

A tetrahedral beam that can be compactly stowed, sequentially deployed, and widely manipulated to provide a structurally sound yet highly maneuverable truss structure is comprised of a number of repeating units of tandem tetralhedral sharing common sides. Fixed length battens are jointed into equilateral triangles called batten frames. Apexes of adjacent triangles are interconnected by longerons having a mid-point folding hinge. Joints, comprised of gussets pivotabley connected by links, permit two independent degrees of rotational freedom between joined adjacent batten frames, and provide a stable structure from packaged configuration to complete deployment. The longerons and joints can be actuated in any sequence, independently of one another. The beam is suited to remote actuation. Longerons may be provided with powered mid-point hinges enabling beam erection and packaging under remote control. Providing one or more longerons with powered telescoping segments permits the shape of the beam central axis to be remotely manipulated so that the beam may function as a remote manipulator arm

Predation by Amphibians and Small Mammals on the Spruce Budworm (Lepidoptera: Tortricidae)

Stomach-content analyses of pitfall-trapped amphibians and small mammals showed that the eastern American toad, Bujo americanus americanus, and the wood frog, Rana sylvatica, preyed on late instars and moths of the spruce budworm, Choristoneura fumiferana. The spotted salamander, Ambystoma maculatum, and the masked shrew, Sorex cinereus, also preyed on late instars of the spruce budworm

Effect of control logic modifications on airstart performance of F100 engine model derivative engines in an F-15 airplane

A series of airstarts were conducted in an F-15 airplane with two prototype Pratt and Whitney F100 Engine Model Derivative engines equipped with Digital Electronic Engine Control (DEEC) systems. The airstart envelope and the time required for airstarts were defined. Comparisons were made between the original airstart logic, and modified logic which was designed to improve the airstart capability. Spooldown airstarts with the modified logic were more successful at lower altitudes than were those with the original logic. Spooldown airstart times ranged from 33 seconds at 250 knots to 83 seconds at 175 knots. The modified logic improved the airstart time from 31% to 53%, with the most improved times at slower airspeeds. Jet fuel starter (JFS)-assisted airstarts were conducted at 7000 m and airstart times were significantly faster than unassisted airstarts. The effect of altitude on airstart times was small

Spectroscopic Study Of The Use Of Lanthanide Metalloporphyrins As Sensors For Benzene And Acetonitrile Detection In Aqueous Studies

This work entails the research on lanthanide metalloporphyrins for their potential use as chemical sensors for benzene and acetonitrile. This research is of importance due to the health implications that benzene and acetonitrile cause; benzene is a known carcinogen and acetonitrile is a known lung irritant. The use of UV-Vis spectroscopy, Fluorescence spectroscopy, Gaussian DFT, and X-ray diffraction crystallography were used in the characterization and analysis of the lanthanide porphyrin complexes. Europium, terbium, dysprosium, cerium, and gadolinium were the lanthanides used in conjunction with 5,10,15,20-tetraphenylporphyrin, TPP and 5,10,15,20 tetrakissulfonato porphyrin, TBSP. Based on the luminescence spectroscopy and UV-Vis spectroscopy data, an aqueous sensor for acetonitrile and benzene was shown to be promising. Among the compounds studied, EuTPP and DyTPP complexes exposed to sodium hydroxide showed promising results for sensing acetonitrile due to significant narrowing of the soret band and the decrease of Q bands in the UV-Vis spectra, along with the blue shifting of luminescence emission spectra. On the other hand, the CeTPP and EuTPP solutions show promise as benzene sensors due to the blue shifting of emission luminescence and variation in intensity. Based on the lanthanide TBSP complexes, TbTBSP was shown to be a promising sensor for acetonitrile due to the narrow soret band, decreased Q bands, and blue shifted emission spectra. EuTBSP, DyTBSP, and TbTBSP were shown to be promising for benzene sensors. Benzene stabilized the TBSP at a higher energy state, S2, to facilitate the energy transfer to the lanthanide ions

An analysis of the transient behavior of infiltrated tungsten composites including the effect of the melt layer Final report

Transient one dimensional heat transfer analysis of infiltrated tungsten composite

Notes and Descriptions of Bees

The specimens on which this paper is based are in the collection of the University of Nebraska, unless otherwise stated. Especial acknowledgments are due to Prof. Cockerell for specimens and suggestions, to Prof. Titus for specimens, and to Prof. Bruner for overseeing my work

Development Of Human Adaptation To Cold

Thesis (Ph.D.) University of Alaska Fairbanks, 197