Amino acid analysis

The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques

Performance prediction of point-based three-dimensional volumetric measurement systems

Point-based three-dimensional volumetric measurement systems are defined as multi-view vision systems which reconstruct a three-dimensional scene by first identifying key points on the views and then performing the reconstruction. Examples of these are defocusing digital particle image velocimetry (DDPIV) (Pereira et al 2000 Exp. Fluids 29 S78–84) and 3D particle tracking velocimetry (3DPTV) (Papantoniou and Maas 1990 5th Int. Symp. on the Application of Laser Techniques in Fluid Mechanics) which reconstruct clouds of flow tracers in order to estimate flow velocities. The reconstruction algorithms in these systems are variations of an epipolar line search. This paper presents a generalized error analysis of such methods, both in reconstruction precision (error in the reconstructed scene) and reconstruction quality (number of ambiguities or 'ghosts' produced)

Fundamentals of the oxidation protection of columbium and tantalum Semiannual report, Apr. 1 - Oct. 1, 1967

Oxidation protection of niobium and tantalum by their silicide

Fundamentals of the oxidation protection of columbium and tantalum Semiannual report, 1 Apr. - 1 Oct. 1969

Oxidation protection by silicides of niobium and tantalum, and thermochemical dat

Fundamentals of the oxidation protection of tantalum Final report

Fundamentals of oxidation protection of tantalum by silicide

Compressible Flows in Fluidic Oscillators

We present qualitative observations on the internal flow characteristics of fluidic oscillator geometries commonly referred to as sweeping jets in active flow control applications. This is part of the fluid dynamics videos.Comment: Videos include

Estimating and forecasting production and orders in manufacturing industry from business survey data: Evidence from Switzerland 1990-2003

A fundamental issue for policy-oriented business cycle research is access to leading - or at least coincident - and reliable indicators of economic activity in manufacturing industry. Therefore, we analyse how the quickly disposable, qualitative information of the business tendency survey conducted by the Swiss Institute for Business Cycle Research (KOF) is related to the official production and order statistics of Switzerland. Pairs of high cross-correlations were selected for further analyses (Granger causality, pattern of turning points). In the next step, the remaining variables are used as predictors of the official statistics in a bivariate and multivariate approach. The results show a very high and stable relationship between the two data-sets particularly for nowcasts and - though to a somewhat lesser degree - for short term prognostics

Low frequency elastic wave propagation in 2D locally resonant phononic crystal with asymmetric resonator

The resonance modes and the related effects to the transmission of elastic waves in a two dimensional phononic crystal formed by periodic arrangements of a two blocks unit cell in one direction are studied. The unit cell consists of two asymmetric elliptic cylinders coated with silicon rubber and embedded in a rigid matrix. The modes are obtained by the semi-analytic method in the least square collocation scheme and confirmed by the finite element method simulations. Two resonance modes, corresponding to the vibration of the cylinder along the long and short axes, give rise to resonance reflections of elastic waves. One mode in between the two modes, related to the opposite vibration of the two cylinders in the unit cell in the direction along the layer, results in the total transmission of elastic waves due to zero effective mass density at the frequency. The resonance frequency of this new mode changes continuously with the orientation angle of the elliptic resonator.Comment: 17 pages, 7 figure

Impact resistance of spar-shell composite fan blades

Composite spar-shell fan blades for a 1.83 meter (6 feet) diameter fan stage were fabricated and tested in a whirling arm facility to evaluate foreign object damage (FOD) resistance. The blades were made by adhesively bonding boron-epoxy shells on titanium spars and then adhesively bonding an Inconel 625 sheath on the leading edge. The rotating blades were individually tested at a tip speed of 800 feet per second. Impacting media used were gravel, rivets, bolt, nut, ice balls, simulated birds, and a real bird. Incidence angles were typical of those which might be experienced by STOL aircraft. The tests showed that blades of the design tested in this program have satisfactory impact resistance to small objects such as gravel, rivets, nuts, bolts, and two inch diameter ice balls. The blades suffered nominal damage when impacted with one-pound birds (9 to 10 ounce slice size). However, the shell was removed from the spar for a larger slice size