E-conomies of Trust

The Internet is like an engine driving commerce into a future rich with opportunity and challenge. Despite the potential, many organisations are reluctant to participate. Their executives feel they lack sufficient control in this new environment. Some want to take a more measured approach, with safeguards to protect them against hazards.

New double indentation technique for measurement of the elasticity modulus of thin objects

In this paper we introduce a new method to determine the Young's modulus of thin (biological) samples. The method is especially suitable for small objects with a thickness of a few hundred micrometers. Such specimens cannot be examined with existing tests: compression and tensile tests need well-known geometry and boundary conditions while classic indentation tests need relatively thick pieces of material. In order to determine the elastic modulus we use the indentation theory as proposed by Sneddon and correct it with a finite element calculated kappa factor to compensate for the small thickness. In order to avoid material deformations at the contact zone between the sample bottom and the sample stage, we replace the sample stage by a second indentation needle. In this way the sample can be clamped between two identical needles and a virtual mirror plane is introduced. The new method was used on four test-materials and results agreed well with the outcome of a standard compression method applied on large samples of the same materials. As an application example the technique was applied on thin biological samples, namely middle ear ossicles of rabbits

Contextual viewpoint to quantum stochastics

We study the role of context, complex of physical conditions, in quantum as well as classical experiments. It is shown that by taking into account contextual dependence of experimental probabilities we can derive the quantum rule for the addition of probabilities of alternatives. Thus we obtain quantum interference without applying to wave or Hilbert space approach. The Hilbert space representation of contextual probabilities is obtained as a consequence of the elementary geometric fact: $\cos$-theorem. By using another fact from elementary algebra we obtain complex-amplitude representation of probabilities. Finally, we found contextual origin of noncommutativity of incompatible observables

Fusion bonding of carbon fabric reinforced polyphenylene sulphide

In recent years, there is a growing interest in joining techniques for thermoplastic composites as an alternative to adhesive bonding. In this manuscript, a fusion bonding process called hot-tool welding is investigated for this purpose and the used material is a carbon fabric reinforced polyphenylene sulphide. The quality of the welds is experimentally assessed using a short three-point bending setup, which has an interesting distribution of interlaminar shear stresses. It can be concluded that although the hot-tool welding process shows high short-beam strengths, it has some drawbacks. Therefore, a design of an infrared welding setup is presented

On Peres' statement "opposite momenta lead to opposite directions", decaying systems and optical imaging

We re-examine Peres' statement ``opposite momenta lead to opposite directions''. It will be shown that Peres' statement is only valid in the large distance or large time limit. In the short distance or short time limit an additional deviation from perfect alignment occurs due to the uncertainty of the location of the source. This error contribution plays a major role in Popper's orginal experimental proposal. Peres' statement applies rather to the phenomenon of optical imaging, which was regarded by him as a verification of his statement. This is because this experiment can in a certain sense be seen as occurring in the large distance limit. We will also reconsider both experiments from the viewpoint of Bohmian mechanics. In Bohmian mechanics particles with exactly opposite momenta will move in opposite directions. In addition it will prove particularly usefull to use Bohmian mechanics because the Bohmian trajectories coincide with the conceptual trajectories drawn by Pittman et al. In this way Bohmian mechanics provides a theoretical basis for these conceptual trajectories.Comment: 20 pages, 3 figures, LaTex, to be published in Found. Phy

Feasibility study of fusion bonding for carbon fabric reinforced Polyphenylene Sulphide by hot-tool welding

In recent years, there is a growing interest in joining techniques for thermoplastic composites as an alternative to adhesive bonding. In this article, a fusion bonding process called hot-tool welding is investigated for this purpose and the used material is a carbon fabric reinforced polyphenylene sulphide. The welds are first observed through a microscope, after which the quality is experimentally assessed using a short three-point bending setup. A comparison is made between the welded specimens and the equivalent hot pressed specimens. It can be concluded that the hot-tool welding process is very promising for the welding of material under study and that the short three-point bending setup proves interesting for evaluating bonds between composite specimens