15,727 research outputs found
Automotive gas turbine fuel control
A fuel control system is reported for automotive-type gas turbines and particulary advanced gas turbines utilizing variable geometry components to improve mileage and reduce pollution emission. The fuel control system compensates for fuel density variations, inlet temperature variations, turbine vane actuation, acceleration, and turbine braking. These parameters are utilized to control various orifices, spool valves and pistons
Gas turbine engine fuel control
A variable orifice system is described that is responsive to compressor inlet pressure and temperature, compressor discharge pressure and rotational speed of a gas-turbine engine. It is incorporated into a hydraulic circuit that includes a zero gradient pump driven at a speed proportional to the speed of the engine. The resulting system provides control of fuel rate for starting, steady running, acceleration and deceleration under varying altitudes and flight speeds
A degree bound for codimension two lattice ideals
Herzog and Srinivasan have conjectured that for any homogeneous k-algebra,
the degree is bounded above by a function of the maximal degrees of the
syzygies. Combining the syzygy quadrangle decomposition of Peeva and Sturmfels
and a delicate case analysis, we prove that this conjectured bound holds for
codimension 2 lattice ideals
Methods of attenuating wind turbine ac generator output variations
Wind speed variation, tower blockage and structural and inertial factors produce unsteady torque in wind turbines. Methods for modifying the turbine torque so that steady torque is delivered to the coupled ac generator are discussed. The method that may evolve will be influenced by the power use that develops and the trade-offs of cost, weight and complexity
Torsional suspension system for testing space structures
A low frequency torsional suspension system for testing a space structure uses a plurality of suspension stations attached to the space structure along the length thereof in order to suspend the space structure from an overhead support. Each suspension station includes a disk pivotally mounted to the overhead support, and two cables which have upper ends connected to the disk and lower ends connected to the space structure. The two cables define a parallelogram with the center of gravity of the space structure being vertically beneath the pivot axis of the disk. The vertical distance between the points of attachment of the cables to the disk and the pivot axis of the disk is adjusted to lower the frequency of the suspension system to a level which does not interfere with frequency levels of the space structure, thereby enabling accurate measurement
Competing magnetic interactions in CeNi9-xCoxGe4
CeNi9Ge4 exhibits outstanding heavy fermion features with remarkable
non-Fermi- liquid behavior which is mainly driven by single-ion effects. The
substitution of Ni by Cu causes a reduction of both, the RKKY coupling and
Kondo interaction, coming along with a dramatic change of the crystal field
(CF) splitting. Thereby a quasi-quartet ground state observed in CeNi9Ge4
reduces to a two-fold degenerate one in CeNi8CuGe4. This leads to a
modiffcation of the effective spin degeneracy of the Kondo lattice ground state
and to the appearance of antiferromagnetic (AFM) order. To obtain a better
understanding of consequences resulting from a reduction of the effective spin
degeneracy, we stepwise replaced Ni by Co. Thereby an increase of the Kondo and
RKKY interactions through the reduction of the effective d-electron count is
expected. Accordingly, a paramagnetic Fermi liquid ground state should arise.
Our experimental studies, however, reveal AFM order already for small Co
concentrations, which becomes even more pronounced with increasing Co content
x. Thereby the modiffcation of the effective spin degeneracy seems to play a
crucial role in this system
Comment on: Weak Anisotropy and Disorder Dependence of the In-Plane Magnetoresistance in High-Mobility (100) Si Inversion Layers
Comment on: Weak Anisotropy and Disorder Dependence of the In-Plane
Magnetoresistance in High-Mobility (100) Si Inversion LayersComment: 1 page, submitted to PR
The surface geometry of inherited joint and fracture trace patterns resulting from active and passive deformation
Hypothetical models are considered for detecting subsurface structure from the fracture or joint pattern, which may be influenced by the structure and propagated to the surface. Various patterns of an initially orthogonal fracture grid are modeled according to active and passive deformation mechanisms. In the active periclinal structure with a vertical axis, fracture frequency increased both over the dome and basin, and remained constant with decreasing depth to the structure. For passive periclinal features such as a reef or sand body, fracture frequency is determined by the arc of curvature and showed a reduction over the reefmound and increased over the basin
Ambulation protocols leading to decreased postoperative complications and hospital stay
Background:
In the postoperative course, patients are routinely encouraged to ambulate as frequently as possible. Typically in the hospital this can become burdensome to the staff and often becomes low priority. Patients are also not aware of the frequency and quality of the ambulation that is sufficient in the postoperative period. At present, patients on the surgical floor who are completely independent and without any devices (eg. Oxygen, nasogastric tubes, chest tubes) are freely able to ambulate at will although there is no reliable way to track this progress. Other patients with devices are limited to waiting for nursing or ancillary staff to assist them with securing the devices that they require in the postoperative period. Ambulation has been positively associated with decreased postoperative complications ranging from bowel function to deep venous thrombosis to pneumonia.https://jdc.jefferson.edu/patientsafetyposters/1065/thumbnail.jp
- …