Advances in electrical high current connections for electrical propulsion systems

Many countries strongly support electric propulsion for various fields of transportation, be it people or goods on land, at sea or in the air. Although electric drive systems appear much simpler than (internal) combustion systems, they exhibit their own challenging development tasks. This becomes obvious when an ever-increasing efficiency, performance or production rate is required, just to name a few. The new challenges can be tackled with the help of new electromagnetic manufacturing processes. High speed processes with their well-known unique capabilities offer promising approaches. However, development is required in order to deliver the required performance. High-speed forming with electromagnetic tools allows the production of sharp-edged battery housings. For body panels, sharp edges are mainly a design feature. For batteries, however, sharp edges allow for an almost ideally rectangular housing, enabling a higher energy density. Increases in the range of up to 10 % are achievable. When it comes to packaging, the liquid cooling and heating of battery packs is of equally large importance. The channels for the medium must not consume too much space. The integration of channels inside the aluminium or steel frame of the battery pack is a promising approach. Due to the high welding speeds of up to 500 mm per second at optimum conditions and at the same time the ability to weld aluminium to aluminium or even steel without any loss in strength, electromagnetic pulse welding offers a promising solution. The conduction of high electrical currents with for example the strong demand to save weight and thus use as little material as possible also requires new processes. Electromagnetic pulse welding of aluminium to aluminium and aluminium to copper is well known, investigated and already used in mass production. However, this is suitable for bus bars only. The connection of terminals to cables is mostly done by crimping. Using a pulsed force for crimping improves the compaction and thus the resistance of the joint, especially of cables with large cross sections. This allows for smaller connectors and reduced cable cross sections

Stable computational methods for additive binomial models with application to adjusted risk differences

Risk difference is an important measure of effect size in biostatistics, for both randomised and observational studies. The natural way to adjust risk differences for potential confounders is to use an additive binomial model, which is a binomial generalised linear model with an identity link function. However, implementations of the additive binomial model in commonly used statistical packages can fail to converge to the maximum likelihood estimate (MLE), necessitating the use of approximate methods involving misspecified or inflexible models. A novel computational method is proposed, which retains the additive binomial model but uses the multinomial–Poisson transformation to convert the problem into an equivalent additive Poisson fit. The method allows reliable computation of the MLE, as well as allowing for semi-parametric monotonic regression functions. The performance of the method is examined in simulations and it is used to analyse two datasets from clinical trials in acute myocardial infarction. Source code for implementing the method in R is provided as supplementary material (see Appendix A).Australian Research Counci

Development of a Radioimmunoassay for Pig Pancreatic Kallikrein

Peer Reviewe

Suitable Design for Electromagnetic Pulse Processes

Basic conventional production processes, such as arc welding or forming, are more or less thoroughly investigated, reliable process guidelines have been developed and trained engineers are available. This allows them to be put into use usually fast, thus facilitating a wide application. The usage of electromagnetic pulse processes, on the contrary, still lacks a broad propagation. Despite having a history reaching back several decades, these processes are mostly limited to niche applications. Admittedly, theoretical considerations have been made and various experiments have been carried out. However, when a given joining or forming task needs to be realized with electro-magnetic force, a huge invest is necessary even before the first part is made. This involves the design of the machine, especially of the tool coil, as well as the design of the workpieces to be processed. In industrial environmentsthis challenge is tackled step by step: After the theoretical product concept in close collaboration with the customer, numerical and experimental trials are carried out. In many cases, iterations are necessary and both geometry and process are optimized. The experimental trials can be conducted with universal sheet welding tool coils or tube compression tool coils with custom field shapers. This procedure allows keeping the prototyping costs low, but at the same time provides valid information on the feasibility in general, the requirements to the workpieces, the design of the tool coil and the properties of the pulse generator. Subsequently, the tool coil is designed and manufactured according to the prior findings. The pulse generator as modular component is assembled and adapted to the customer’s requirements. The iterative product and process design is the most important phase of the whole procedure, which is in accordance with good project management. It significantly lowers the risk of an expensive project cancellation during the late steps

De-noising of diffusion-weighted MRI data by averaging of inconsistent input data in wavelet space

Diffusion Weighted Images datasets with high spatial resolution and strong diffusion weighting are often deteriorated with low SNR. Here, we demonstrate the feasibility of a recently presented repetition-free averaging based de-noising (AWESOME). That technique reduces noise by averaging over a series of N images with varying contrast in wavelet space and regains intensities and object features initially covered by noise. We show that high resolution DWIs are achievable in a quality that almost equals to that obtained from 6fold complex averaging