9,779 research outputs found
Bounded gaps between primes with a given primitive root, II
Let be a natural number, and let be a set containing at
least primes. We show that one can find infinitely many strings of
consecutive primes each of which has some as a primitive
root, all lying in an interval of length . This is
a bounded gaps variant of a theorem of Gupta and Ram Murty. We also prove a
result on an elliptic analogue of Artin's conjecture. Let be an
elliptic curve with an irrational -torsion point. Assume GRH. Then for every
, there are infinitely many strings of consecutive primes for which
is cyclic, all lying an interval of length . If has CM, then the GRH assumption can be removed. Here , ,
and are absolute constants
A method for measuring cooling air flow in base coolant passages of rotating turbine blades
Method accurately determines actual coolant mass flow rate in cooling passages of rotating turbine blades. Total and static pressures are measured in blade base coolant passages. Mass flow rates are calculated from these measurements of pressure, measured temperature and known area
On the freeness of anticyclotomic selmer groups of modular forms
We establish the freeness of certain anticyclotomic Selmer groups of modular forms. The freeness of these Selmer groups plays a key role in the Euler system arguments introduced by Bertolini and Darmon in their work on the anticyclotomic main conjecture for modular forms. In particular, our result fills some implicit gaps which appeared in generalizations of the Bertolini-Darmon result to the case where the associated residual representation is not minimally ramified. The removal of such a minimal ramification hypothesis is essential for applications involving congruences of modular forms.Accepted manuscrip
A critical test of the electrical discharge model of the Venus microwave emission
Critical test of electric discharge model for Venus microwave emissio
Evaluation differences on Mars
Space science research on elevation differences on Mar
An analysis of Martian photometry and polarimetry
Martian surface photometry and polarimetry analysi
Optical Detection of Blade Flutter
Dynamic strain gages mounted on rotor blades are used as the primary instrumentation for detecting the onset of flutter and defining the vibratory mode and frequency. Optical devices are evaluated for performing the same measurements as well as providing supplementary information on the vibratory characteristics. Two separate methods are studied: stroboscopic imagery of the blade tip and photoelectric scanning of blade tip motion. Both methods give visual data in real time as well as video tape records. The optical systems are described, and representative results are presented. The potential of this instrumentation in flutter research is discussed
Flow measurement in base cooling air passages of a rotating turbine blade
The operational performance is decribed of a shaft-mounted system for measuring the air mass flow rate in the base cooling passages of a rotating turbine blade. Shaft speeds of 0 to 9000 rpm, air mass flow rates of 0.0035 to 0.039 kg/sec (0.0077 to 0.085 lbm/sec), and blade air temperatures of 300 to 385 K (80 to 233 F) were measured. Comparisons of individual rotating blade flows and corresponding stationary supply orifice flows agreed to within 10 percent
- …