The tests establish certified aircraft Effective Perceived Noise Levels (EPNLs
) for each of the flight conditions: approach, flyover and sideline.
EPPL complexe, in conditii de stationar, au fost efectuate in 82 de cazuri (28,3 % din intreg lotul de cercetare), din care 71 de pacienti sau 86,5 % fiind adulti si 12 minori, cu 13,5 %; EPNL complexe, in conditii de stationar, au fost efectuate in 13 cazuri (4,5 % din intreg lotul de cercetare), toti fiind persoane mature si EPSL complexe, in conditii de stationar, care au constituit 1 % din intreg lotul de cercetare, inregistrand trei cazuri la adulti.
Structura EPL complexe in lotul de cercetare, in functie de categoriile de varsta (%) minori EPPL stat 4.10% EPPL amb 25.80% EPNL stat EPNL amb 0.30% EPS L stat EPSL amb adulti EPPL stat 24.40% EPPL amb 21.60% EPNL stat 4.50% EPNL amb 13.70% EPS L stat 1% EPSL amb 3% Note: Table made from bar graph.
NASA studied the amount of EPNL reduction for the following nozzle configurations: chevrons were installed only on the fan exhaust, only on the core exhaust, and on both.
A substantial benefit in EPNL occurs when the vanes have dissimilar angles of attack, with the upper pair at smaller incidence than the lower pair.
Papamoschou, subscale aero acoustic experiments simulated the exhaust flow of a turbofan engine with a bypass ratio of 6.0 (Papamoschou 2004c) Deflection of the bypass stream resulted in suppression of the overall peak sound pressure level by 4.5 dB and the effective perceived noise level (EPNL) by 2.8 dB.
They also considered the addition of a porous wedge-shaped fan flow deflector and show FFD increases the EPNL reductions to 5.0 dB and 3.9 dB in the downward and sideline directions, respectively.
Only the discovery and rapid development of new fields could ensure EPNL's survival in Nigeria and avoid massive staff reductions.
Crude oil will be evacuated through a 40km pipeline linked to EPNL's existing Odudu floating production, storage and offloading terminal, which has been exporting oil since 1993.
In July 1990, EPNL spudded the Amenam-1 well, which was drilled to a total depth of 4,028 metres: The discovery of the Amenam field also proved the existence of deep sands with substantial oil and gas condensate columns in this area.
Through these discoveries, EPNL has demonstrated the prospectivity of a new oil play, which is known as "deep Delta".
Thus, Elf thoroughly reinforced its position in Nigeria and EPNL is now one of the major subsidiaries of the Elf group in terms of proven reserves.