Abating exhaust noises in jet engines

A noise abating improvement for jet engines including turbojets, turbofans, turboprops, ramjets, scramjets, and hybrid jets is introduced. A provision is made for an apparatus in the primary and/or secondary flow streams of the engines; the apparatus imparts to the exhaust gases a component rotation or swirl about the engine's longitudinal axis. The rotary component in the exhaust gases causes a substantial suppression of sound energy build up normally produced by an axial flow exhaust system

Minimization of jet and core noise by rotation of flow

Jet and core noise can be reduced and flame lengths may be significantly decreased when exhaust gases are caused to rotate or swirl about longitudinal axis of exhaust. Combustion in rotating flows is steady and quiet, and is not accompanied by pulsations or violent fluctuations

Rare events in networks with internal and external noise

We study rare events in networks with both internal and external noise, and develop a general formalism for analyzing rare events that combines pair-quenched techniques and large-deviation theory. The probability distribution, shape, and time scale of rare events are considered in detail for extinction in the Susceptible-Infected-Susceptible model as an illustration. We find that when both types of noise are present, there is a crossover region as the network size is increased, where the probability exponent for large deviations no longer increases linearly with the network size. We demonstrate that the form of the crossover depends on whether the endemic state is localized near the epidemic threshold or not

Planetary film reconnaissance system

Design, fabrication, assembly of planetary film reconnaissance syste

Survey of electric power plants for space applications

Fuel and solar cells, chemical batteries, Rankine and Brayton cycle power plants, thermoelectric generators, and thermionic converters for space power application

Exploring the Feasibility of Incorporating Sexual Education into Routine Adolescent Office Visits

Preventative sexual education can reduce the negative health outcomes of sexual behavior in adolescent populations.1 The objective of this pilot study was to determine if sexual education can be delivered as a scripted five-minute module during a routine adolescent office visit in a manner that is non-disruptive of clinic flow and acceptable to both patients and providers. • 85% of providers reported the intervention did not interrupt clinic flow • 86% of patients reported the intervention to be appropriate and 92% of providers were satisfied overall with the intervention These pilot data highlight that the incorporation of brief scripted sexual education into routine adolescent preventative office visits is both feasible and acceptable to patients and providers.https://jdc.jefferson.edu/cwicposters/1024/thumbnail.jp

Fourier transform and rigidity of certain distributions

Let $E$ be a finite dimensional vector space over a local field, and $F$ be its dual. For a closed subset $X$ of $E$, and $Y$ of $F$, consider the space $D^{-\xi}(E;X,Y)$ of tempered distributions on $E$ whose support are contained in $X$ and support of whose Fourier transform are contained in $Y$. We show that $D^{-\xi}(E;X,Y)$ possesses a certain rigidity property, for $X$, $Y$ which are some finite unions of affine subspaces.Comment: 10 page