Fixed base simulator study of an externally blown flap STOL transport airplane during approach and landing

A fixed-base simulator study was conducted to determine the flight characteristics of a representative STOL transport having a high wing and equipped with an external-flow jet flap in combination with four high-bypass-ratio fan-jet engines during the approach and landing. Real-time digital simulation techniques were used. The computer was programed with equations of motion for six degrees of freedom and the aerodynamic inputs were based on measured wind-tunnel data. A visual display of a STOL airport was provided for simulation of the flare and touchdown characteristics. The primary piloting task was an instrument approach to a breakout at a 200-ft ceiling with a visual landing

Secondary gamma-ray production in a coded aperture mask

The application of the coded aperture mask to high energy gamma-ray astronomy will provide the capability of locating a cosmic gamma-ray point source with a precision of a few arc-minutes above 20 MeV. Recent tests using a mask in conjunction with drift chamber detectors have shown that the expected point spread function is achieved over an acceptance cone of 25 deg. A telescope employing this technique differs from a conventional telescope only in that the presence of the mask modifies the radiation field in the vicinity of the detection plane. In addition to reducing the primary photon flux incident on the detector by absorption in the mask elements, the mask will also be a secondary radiator of gamma-rays. The various background components in a CAMTRAC (Coded Aperture Mask Track Chamber) telescope are considered. Monte-Carlo calculations are compared with recent measurements obtained using a prototype instrument in a tagged photon beam line

Antioxidative Properties of Bitter Gourd (Momordica charantia) and Zucchini (Cucurbita pepo)

The enzymatic and non-enzymatic antioxidative capacities of bitter gourd (Momordica charantia) and zucchini (Cucurbita pepo) were investigated in water extracts and chemical buffer extracts. Bitter gourd and zucchini fruits were purchased from a farmer’s market and homogenized separately in water and in a native enzyme extraction buffer. Total phenolic compounds, free radical DPPH scavenging activity, SOD activity and β- glucosidase activity were assayed in the extracts. The average total phenolic compounds recorded in bitter gourd were 13.28 GAE/g fresh weights while in zucchini, the average was 8.67GAE/g fresh weight. This study also found that bitter gourd was 82.05% as effective as ascorbic acid in inhibiting the free radical DPPH while zucchini was 12.19% as effective. The results indicated that bitter gourd was significantly higher in antioxidant content and in β-glucosidase activities than zucchini (P\u3c0.05). On the other hand, significantly higher SOD activities were recorded in zucchini than in bitter gourd extracts

Self-stabilised fractality of sea-coasts through damped erosion

Erosion of rocky coasts spontaneously creates irregular seashores. But the geometrical irregularity, in turn, damps the sea-waves, decreasing the average wave amplitude. There may then exist a mutual self-stabilisation of the waves amplitude together with the irregular morphology of the coast. A simple model of such stabilisation is studied. It leads, through a complex dynamics of the earth-sea interface, to the appearance of a stationary fractal seacoast with dimension close to 4/3. Fractal geometry plays here the role of a morphological attractor directly related to percolation geometry.Comment: 4 pages, 5 figure

Non-Linear Effects in Non-Kerr spacetimes

There is a chance that the spacetime around massive compact objects which are expected to be black holes is not described by the Kerr metric, but by a metric which can be considered as a perturbation of the Kerr metric. These non-Kerr spacetimes are also known as bumpy black hole spacetimes. We expect that, if some kind of a bumpy black hole exists, the spacetime around it should possess some features which will make the divergence from a Kerr spacetime detectable. One of the differences is that these non-Kerr spacetimes do not posses all the symmetries needed to make them integrable. We discuss how we can take advantage of this fact by examining EMRIs into the Manko-Novikov spacetime.Comment: 8 pages, 3 Figures; to appear in the proceedings of the conference "Relativity and Gravitation: 100 Years after Einstein in Prague" (2012

METHODOLOGICAL INVESTIGATION OF VIBRATION EFFECTS ON PERFORMANCE OF THREE TASKS

ABSTRACT Twenty young Navy e n l i s t e d male volunteers were f i r s t rehearsed and then t e s t e d before, during. and a f t e r whole-body v i b r a t i o n . Fourteen were t e s t e d only a t 8 Hz, and six were t e s t e d a t 8 Hz/0.21 g rms, 16 HzI0.43 & rms and 32 HzI0.85 & rms. using t h r e e paper-and-pencil t a s k s involving v i s u a l , motor, and c o g n i t i v e s k i l l s . The t a s k s were "Spoke". a speed of tapping test; "Aiming", a test of f i n e motor coordination; and "Coding", involving mental computation. Results showed an approximately equal decrement e f f e c t a c r o s s conditions i n t h e Spoke and Coding (but not Aiming) tests t h a t conforms w i t h t h e frequency function embodied i n t h e c u r r e n t i n t e r n a t i o n a l standard ( I S 0 2631:1978) on human exposure t o v i b r a t i o n ; but t h a t a modicum of previous v i b r a t i o n experience may be necessary before r e l i a b l e d a t a are obtained i n t h i s kind of t e s t i n g . t i o n of t h e c u r r e n t standard are b r i e f l y discussed. Implications f o r methodology and f o r t h e applica

Operating characteristics of a prototype high energy gamma-ray telescope

The field of gamma-ray astronomy in the energy range from ten to several hundred MeV is severely limited by the angular resolution that can be achieved by present instruments. The identification of some of the point sources found by the COS-B mission and the resolution of detailed structure existing in those sources may depend on the development of a new class of instrument. The coded aperture mask telescope, used successfully at X-ray energies hold the promise of being such an instrument. A prototype coded aperture telescope was operated in a tagged photon beam ranging in energy from 23 to 123 MeV. The purpose of the experiment was to demonstrate the feasibility of operating a coded aperture mask telescope in this energy region. Some preliminary results and conclusions drawn from some of the data resulting from this experiment are presented