Logic AND gate for fluid circuits Patent

Logic AND gate for fluid circuit

Wall attachment, flueric crossover ''AND'' gate

Gate performance is not adversely affected by normal dimensional variations encountered in fabrication and it operates throughout full loading range. Flow from one control must be sufficiently monostable to allow initial attachment and upon switching, return to outer wall. Venting must be adequate

Fluid pressure amplifier and system

A flueric beam-deflection amplifier and a method of controlling the same are described. Either a single or a series of cascaded fluid amplifier units are provided and each one of which may include the usual power nozzle, control nozzles, outlet passages and vent passages. All vent passages of each fluid amplifier unit lead to an enclosed vent outlet chamber which is connected to the ambient environment or to a return manifold through a variably restricted passage. To control the fluid amplifier unit, power and control stream pressures are first established, after which the restricted passage is reduced to regulate the input bias, the gain and the input impedance of the fluid amplifier unit

Evaluating potential drivers of four different types of moose browsing damage in a cross-border context

Moose (Alces alces) in Scandinavia rely on commercially valuable Scots pine (Pinus sylvestris) as a winter food source. Browsing impacts to forest resources are labeled as “damage” and have become especially important along the border between Norway and Sweden, where a semi-migratory moose population moves seasonally between two management regimes. As part of the EU-funded GRENSEVILT project, we studied multiple factors thought to drive browsing damages within a single sub-population in a cross-border context. We combined elements of two national methods of assessing browsing damage: Solbraa (Norwegian) and Äbin (Swedish). We analyzed four damage indicators (stem breakage, bark browsing, browsing pressure, and number of winter-browsed top shoots) by grouping over 20 predictor variables into three categories, using data collected on 3,033 individual pine trees. GLMM model variable selection was completed using AIC. Covariates that measured severity of prior damage (such as cumulative impacts on plant architecture) were included in the top models for all four indicators. Notably, the covariates for pine density and snow depth, factors previously found to be important in predicting browsing damage, were not present in any of the top models. GAM landscape models revealed that distributions of the four damage types are quite different – with bark browsing illustrating an isolated “hotspot” and browsing pressure showing more widespread prevalence. There is some evidence to suggest that different damage types represent a natural progression of moose foraging, with stem breakage and bark browsing signaling more severe damage and potential over-use with time

Flight evaluation of a simple total energy-rate system with potential wind-shear application

Wind shears can create havoc during aircraft terminal area operations and have been cited as the primary cause of several major aircraft accidents. A simple sensor, potentially having application to the wind-shear problem, was developed to rapidly measure aircraft total energy relative to the air mass. Combining this sensor with either a variometer or a rate-of-climb indicator provides a total energy-rate system which was successfully applied in soaring flight. The measured rate of change of aircraft energy can potentially be used on display/control systems of powered aircraft to reduce glide-slope deviations caused by wind shear. The experimental flight configuration and evaluations of the energy-rate system are described. Two mathematical models are developed: the first describes operation of the energy probe in a linear design region and the second model is for the nonlinear region. The calculated total rate is compared with measured signals for many different flight tests. Time history plots show the tow curves to be almost the same for the linear operating region and very close for the nonlinear region

Thin Layer Composite Unimorph Ferroelectric Driver and Sensor

A method for forming ferroelectric wafers is provided. A prestress layer is placed on the desired mold. A ferroelectric wafer is placed on top of the prestress layer. The layers are heated and then cooled causing the ferroelectric wafer to become prestressed. The prestress layer may include reinforcing material and the ferroelectric wafer may include electrodes or electrode layers may be placed on either side of the ferroelectric layer. Wafers produced using this method have greatly improved output motion

Evaluation of a total energy-rate sensor on a transport airplane

A sensor that measures the rate of change of total energy of an airplane with respect to the airstream has been evaluated. The sensor consists of two cylindrical probes located on the fuselage of a transport airplane, an in line acoustic filter, and a pressure sensing altitude rate transducer. Sections of this report include the sensor description and experimental configuration, frequency response tests, analytical model development, and flight test results for several airplane maneuvers. The results section includes time history comparisons between data generated by the total energy rate sensor and calculated data derived from independent sources

Ferroelectric Stirling-Cycle Refrigerator

A Stirling-cycle refrigerator has a three-pump configuration and pumping sequence, in which one pump serves as a compressor. one pump serves as an expander, and one pump serves as a displacer. The pumps are ferroelectrically actuated diaphragm pumps which are coordinated by synchronizing the ferroelectric-actuator voltages in such a way that the net effect of the displacer is to reduce the deleterious effect of dead space; that is, to circulate a greater fraction of the working fluid through the heat exchangers than would be possible by use of the compressor and expander alone. In addition. the displacer can be controlled separately to make the flow of working fluid in the heat exchangers turbulent (to increase the rate of transfer of heat at the cost of greater resistance to flow) or laminar (to decrease the resistance to flow at the cost of a lower heat-transfer rate)

High Displacement Solid State Ferroelectric Loudspeaker

A piezoelectric loudspeaker suitable for midrange frequencies uses a dome shaped piezoelectric actuator to a speaker membrane directly is discussed. The dome shaped actuator is made from a reduced and internally biased oxygen wafer, and generates excursion of the apex of the dome in the order of 0.02-0.05 inches when a rated drive voltage of 350 V rms is applied between the convex and the concave surface of the dome shaped actuator. The load capacity exceeds 10 lbs. The edge of the rim of the dome shaped actuator must be free to rock when the dome height varies to ensure low distortion in the loudspeaker. This is achieved by mounting the rim of the dome shaped actuator on a support surface by prestress only. An exceptionally simple design uses a planar speaker membrane with the center part of one side pressed against the rim of a dome shaped actuator by prestress from a stretched latex surround member