Development of Steps in an Automated Process Chain for Piezoceramic-Metal Compound Production

The potential of adaptronic applications has been proven in many conceptual studies. A broad use in high-efficiency branches is often hindered by the absence of an appropriate assembly method. Especially for piezoceramic foil transducers, the application on structural parts can be simplified using a semi-finished part that includes the transducer. The part is then shaped in a final forming operation. The purpose of the present study is the investigation of process limits in automated process chains for producing semi-finished parts. An adhesive is used in the process, which is only locally cured. This bi-conditioned state is achieved using cooling and heating elements. The process limits are mainly affected by the choice of temperature and curing time between adhesive application and forming operation. Several tests with a rotational rheometer were carried out to investigate the curing behavior. An appropriate process window was identified varying processing time and temperature. The results were then used to build a model of the curing behavior. A mathematical approach had to be used to find the best configuration because no sharp border exists between the two adhesive conditions of liquid and solid state. The process parameters were proven with runs inside and outside of the process limits.

A cinematographic survey of a selected alternative sub-culture in various locations

This document discusses the motivation for and the process of making a 52 minute television Art documentary designed to inform and to create an awareness of the problem of modern culture and its impact on the environment. Drawing on qualitative research from a worldwide research journey, it investigates modern culture's socially conditioned state and how television has assisted to that end. It then explores the philosophical views and constructs behind the Sixties movement and Rainbow - an alternative social collective that evolved out of the Sixties Movement, and uses these findings to serve as the creative basis for the making of the film, The Search for Utopia.

Quasistationarity of continuous-time Markov chains with positive drift

We shall study continuous-time Markov chains on the nonnegative integers which are both irreducible and transient, and which exhibit discernible stationarity before drift to infinity “sets in”. We will show how this ‘quasi’ stationary behaviour can be modelled using a limiting conditional distribution: specifically, the limiting state probabilities conditional on not having left 0 for the last time. By way of a dual chain, obtained by killing the original process on last exit from 0, we invoke the theory of quasistationarity for absorbing Markov chains. We prove that the conditioned state probabilities of the original chain are equal to the state probabilities of its dual conditioned on non-absorption, thus allowing to establish the simultaneous existence and then equivalence, of their limiting conditional distributions. Although a limiting conditional distribution for the dual chain is always quasistationary distribution in the usual sense, a similar statement is not possible for the original chain.

Pore Structure of Cotton Fabrics Crosslinked with Formaldehyde-Free Reagents

Pore structures of cotton fabric crosslinked with several formaldehyde-free durable press reagents are elucidated, and results are compared with those for the industry standard, DMDHEU (dimethyloldihydroxyethyleneurea). The formaldehyde-free reagents were BTCA (butanetetracarboxylic acid), DHDMI (dihydroxydimethylimidazolidinone), and the glyoxal/glycol system; the fabric was an 80 × 80 cotton print-cloth. Treatments were designed to impart the same degree of conditioned wrinkle recovery (WRA) to the fabric. A reverse gel permeation chromatographic technique was used to follow changes in pore size distribution. Columns were prepared by settling water slurries of the ground cotton in a conventional manner. Two series of water soluble solutes, which were series of oligomeric sugars and ethylene glycols, were used to study the elution characteristics of the unmodified and crosslinked samples. Internal structure differences were also elucidated by means of moisture regain, considered to be a measure of the internal surface of the cotton fiber in the conditioned state, and water of imbibition, a measure of internal volume in the water-swollen state. Formaldehyde-free crosslinking reagents effect a lower level of collapse of the internal pore structure of the cotton fiber than does DMDHEU at generally comparable levels of resilience.

The Sterile Insect Release Method and the Importance of Thermal Conditioning Before Release - Field-Cage Experiments With Dacus-Tryoni in Spring Weather

We present a rationale for the strategy of suppressing the fertility and hence the rate of increase of target populations in spring by the release of sterile insects. Insects for mass release are normally reared in warm conditions and are potentially unsuitable for use in cold weather. A comparison was made of the effectiveness of warm- and cold-conditioned sterile flies in experiments in large field-cages during three successive spring seasons. Sterile males and females, and wild males and females were released into the cages in the ratio 2:2:1:1, respectively. Warm-conditioned sterile flies survived poorly between release and mating. Their mating competitiveness was inferior to that of the wild flies, and they were relatively ineffective in reducing their fertility. Sterile flies released in a cold-conditioned state (equal to that of the wild flies), survived as well as wild flies, and suppressed their fertility to an extent which indicates that their mating competitiveness can be equal to that of the wild flies, if the weather is not too severe. The concept of total competitiveness is introduced. If competitiveness is calculated by means of the ratio of sterile to wild flies that exists at release (rather than at mating), the resulting value is a measure of the potential of the sterile flies to survive to mating age, and to mate in competition with the wild flies. This value is especially pertinent to situations such as a puparial release, when there is a delay between release and mating. In such circumstances, it is needed for calculating the required ratio of sterile to wild insects to achieve the desired reduction of fertility (and thus rate of increase) in the target population.