A study of the structural-acoustic response and interior noise levels of fuselage structures

Models of both flat and curved fuselage panels were tested for their sound transmission characteristics. The effect of external air flow on transmission loss was simulated in a subsonic wind-tunnel. By numerically evaluating the known equations for field-incidence transmission loss of single-walled panels in a computer program, a comparison of the theory with the test results was made. As a further extension to aircraft fuselage simulation, equations for the field-incidence transmission loss of a double-walled panel were derived. Flow is shown to provide a small increase in transmission loss for a flat panel. Curvature is shown to increase transmission loss for low frequencies, while also providing a sharp decrease in transmission loss at the ring frequency of the cylindrical panel. The field-incidence transmission loss of a double-walled panel was found to be approximately twice that for a single-walled panel, with the addition of dips in the transmission loss at the air gap resonances and at the critical frequency of the internal panel

Teaching Trial and Analysis of English for Technical Communication

In this article is described the usage of English for technical communication (ETC), it is a novel development of English for specific purpose on the demand of the society for improving students' ability in communicating technical information. В статті описано використання англійської мови для технічної комунікації, як нестандартного розвитку англійської мови з спеціальних причин на потреби суспільства для доведення здатності студентів в комунікації технічної інформації

Testing in English language, kinds of tests

In this article it is described the testing in English language and different kinds of tests in English language which are mostly used nowadays. В статті описано тестування в англійській мові та різні види тестів в англійській мові

An analytical study of liquid outflow from cylindrical tanks during weightlessness Final report

Liquid outflow from cylindrical tanks during weightlessnes

Ferroelectricity and isotope effects in hydrogen-bonded KDP crystals

Based on an accurate first principles description of the energetics in H-bonded KDP, we conduct a first study of nuclear quantum effects and of the changes brought about by deuteration. Cluster tunneling involving also heavy ions is allowed, the main effect of deuteration being a depletion of the proton probability density at the O-H-O bridge center, which in turn weakens its proton-mediated covalent bonding. The ensuing lattice expansion couples selfconsistently with the proton off-centering, thus explaining both the giant isotope effect, and its close connection with geometrical effects.Comment: 4 two-column pages, 4 figure