The use of discontinuous PEEK/carbon fiber thermoplastic moulding compounds for thick-section componentry

This is the final version. Available on open access from Taylor & Francis via the DOI in this recordThe hot-pressing of discontinuous fiber moulding compounds (DFMCs) is an established way of forming geometrically complex components, however, it is not a simple process. Rapid and irreversible cure cycles hinder the use of thermoset resins, and thermoplastic resins offer inferior mechanical performance. The recent availability of DFMCs utilising a Polyether Ether Ketone (PEEK) matrix offer an alternative, combining the usability of thermoplastics with significantly enhanced mechanical properties. A novel manufacturing approach is proposed and investigated, in which virgin material is consolidated into multiple ‘pre-charges’ prior to pressing the final component, combating the limitations of DFMCs; loft, voidage and fiber orientation. Short beam shear tests were employed to assess the mechanical implications of laminating DFMCs, demonstrating minimal differences to a standard sample. Three-point bend tests assessed rudimentary orientation of fiber bundles, showing significantly improved mechanical performance at the cost of toughness. A novel method to determine the interlaminar shear modulus is also presented and successfully validated.Innovate U

The key aspects of innovation-oriented regional industrial and economic policy

Integration processes taking place in the economy, the new requirements to enhance the effectiveness of production during international competition as well as the need to ensure the social conditions lead to the development and implementation of innovation-oriented regional industrial and economic policy, which in its turn, requires adopting substantial organizational and economic recommendations

Is nonhelical hydromagnetic turbulence peaked at small scales?

Nonhelical hydromagnetic turbulence without an imposed magnetic field is considered in the case where the magnetic Prandtl number is unity. The magnetic field is entirely due to dynamo action. The magnetic energy spectrum peaks at a wavenumber of about 5 times the minimum wavenumber in the domain, and not at the resistive scale, as has previously been argued. Throughout the inertial range the spectral magnetic energy exceeds the kinetic energy by a factor of about 2.5, and both spectra are approximately parallel. At first glance, the total energy spectrum seems to be close to k^{-3/2}, but there is a strong bottleneck effect and it is suggested that the asymptotic spectrum is k^{-5/3}. This is supported by the value of the second order structure function exponent that is found to be \zeta_2=0.70, suggesting a k^{-1.70} spectrum.Comment: 6 pages, 6 figure

Suppression of small scale dynamo action by an imposed magnetic field

Non-helical hydromagnetic turbulence with an externally imposed magnetic field is investigated using direct numerical simulations. It is shown that the imposed magnetic field lowers the spectral magnetic energy in the inertial range. This is explained by a suppression of the small scale dynamo. At large scales, however, the spectral magnetic energy increases with increasing imposed field strength for moderately strong fields, and decreases only slightly for even stronger fields. The presence of Alfven waves is explicitly confirmed by monitoring the evolution of magnetic field and velocity at one point. The frequency omega agrees with vA k1, where vA is the Alfven speed and k1 is the smallest wavenumber in the box.Comment: Final version (7 pages

Personal values in advertisements found in magazines read by teenagers in Southeast Iowa

This study analyzes the types of personal values represented in advertisements contained in magazines read by teenagers. A survey of Southeast Iowa high school media specialists was conducted to identify popular magazines read by students in grades nine through twelve. The five magazines named most frequently in the survey results, Seventeen , People . Teen . Hot Rod and Sports Illustrated, were used to collect data. The researcher analyzed the advertisements contained in January May and September issues to off-set cyclical fluctuations in advertising. Using a list of sixteen personal values, each advertisement was categorized according to its primary value based on visual and textual messages. Findings indicated that personal values such as appearance/sexuality and status/self-esteem ranked among the most prevalent values. whereas values such as family and community were nearly nonexistent

Inertial range scaling in numerical turbulence with hyperviscosity

Numerical turbulence with hyperviscosity is studied and compared with direct simulations using ordinary viscosity and data from wind tunnel experiments. It is shown that the inertial range scaling is similar in all three cases. Furthermore, the bottleneck effect is approximately equally broad (about one order of magnitude) in these cases and only its height is increased in the hyperviscous case--presumably as a consequence of the steeper decent of the spectrum in the hyperviscous subrange. The mean normalized dissipation rate is found to be in agreement with both wind tunnel experiments and direct simulations. The structure function exponents agree with the She-Leveque model. Decaying turbulence with hyperviscosity still gives the usual t^{-1.25} decay law for the kinetic energy, and also the bottleneck effect is still present and about equally strong.Comment: Final version (7 pages

Acetoin is a key odor for resource location in the giant robber crab Birgus latro

The terrestrial and omnivorous robber crab Birgus latro inhabits islands of the Indian Ocean and the Pacific Ocean. The animals live solitarily but occasionally gather at freshly opened coconuts or fructiferous arenga palms. By analyzing volatiles of coconuts and arenga fruit we identified five compounds, including Acetoin, which are present in both food sources. In a behavioral screen performed in the crabs’ habitat, a beach on Christmas Island, we found that of 15 tested fruit compounds Acetoin was the only volatile eliciting significant attraction. Hence, Acetoin might play a key role in governing the crabs’ aggregation behavior at both food sources

Herding model and 1/f noise

We provide evidence that for some values of the parameters a simple agent based model, describing herding behavior, yields signals with 1/f power spectral density. We derive a non-linear stochastic differential equation for the ratio of number of agents and show, that it has the form proposed earlier for modeling of 1/f^beta noise with different exponents beta. The non-linear terms in the transition probabilities, quantifying the herding behavior, are crucial to the appearance of 1/f noise. Thus, the herding dynamics can be seen as a microscopic explanation of the proposed non-linear stochastic differential equations generating signals with 1/f^beta spectrum. We also consider the possible feedback of macroscopic state on microscopic transition probabilities strengthening the non-linearity of equations and providing more opportunities in the modeling of processes exhibiting power-law statistics