Laser welding of aluminum alloys

Recent interest in reducing the weight of automobiles to increase fuel mileage has focused attention on the use of aluminum and associated joining technologies. Laser beam welding is one of the more promising methods for high speed welding of aluminum. Consequently, substantial effort has been expended in attempting to develop a robust laser beam welding process. Early results have not been very consistent in the process requirements but more definitive data has been produced recently. This paper reviews the process parameters needed to obtain consistent laser welds on 5,000 series aluminum alloys and discusses the research necessary to make laser processing of aluminum a reality for automotive applications

Multipartite entangled coherent states

We propose a scheme for generating multipartite entangled coherent states via entanglement swapping, with an example of a physical realization in ion traps. Bipartite entanglement of these multipartite states is quantified by the concurrence. We also use the $N$--tangle to compute multipartite entanglement for certain systems. Finally we establish that these results for entanglement can be applied to more general multipartite entangled nonorthogonal states.Comment: 7 pages, two figures. We added more detail discussions on the generation of multipartite entangled coherent states and multipartite entangelemen

Biobased economy: de potentie van eiwitten voor technische toepassingen

Eiwitten zijn, behalve essentiële bouwstoffen voor mens en dier, tevens bruikbaar voor toepassingen in bijvoorbeeld shampoos, bioplastics, coatings of lijmen. In deze studie is een inventarisatie gemaakt van zowel de huidige beschikbare eiwitbronnen als de bronnen waar in de toekomst veel van verwacht wordt. Mits er voldoende efficiënt met grondstoffen wordt omgesprongen, kunnen voor zowel food als non-food toepassingen wereldwijd voldoende eiwitten worden geproduceerd. Het is wel belangrijk dat de eiwitten die door bioraffinage uit grondstoffen worden gehaald, hun unieke eigenschappen behouden

Kleinschalige bioraffinage in de Achterhoek; een duurzame oplossing voor het mestprobleem

We kampen in Nederland al decennia met een mestprobleem, in feite een mest overschot. In dit rapport worden nieuwe aanpakken van dit probleem voorgesteld, gedeeltelijk gecombineerd met verlaging van mineralen in het voer. De nieuwe aanpak wordt mogelijk indien we er in slagen de efficiëntie van de diervoeders te verbeteren en indien we de belangrijkste componenten van het diervoeder, eiwit en de energie behoefte van de dieren, in Nederland zelf te produceren. Bioraffinage van met name gras en in op termijn ook van mais, is doorslaggevend omdat we daarmee de componenten voor de rundveevoeders kunnen ontsluiten waardoor een hoger rendement wordt bereikt. Door graseiwit in te zetten als varkensvoeder zijn we niet langer afhankelijk van de import van sojaschroot en andere restproducten uit de plantaardige olie verwerkende industrie. Wanneer we deze bioraffinage uitvoeren in kleinschalige fabriekjes, voor de maisraffinage het liefst gekoppeld aan een biogas vergistingsinstallatie, dan kunnen de mineralen die niet voor het dier nodig zijn, direct zonder dure concentreringsbehandelingen naar het agrarische veld terug gebracht worden als bemesting

An Outcome Evaluation of the Implementation of the Triple P – Positive Parenting Program in Hong Kong

The present study evaluated the effectiveness of the Positive Parenting Program (Triple P) with a sample of Chinese parents of children with early onset conduct related problems in Hong Kong. The participants consisted of 91 parents whose children attended maternal and child health centers and child assessment centers for service, and were between three to seven years old. Participants were randomly assigned to the intervention (TP) and a waitlist control group (WL. There was no significant difference in pre-intervention measures between the two groups. However, at post intervention, participants in the TP group reported significantly lower levels of child behavior problems, lower dysfunctional parenting styles, and higher parent sense of competence, compared to the WL group. Implications of these findings for the use of Triple P with families of Chinese descent are discussed

Multiorder coherent Raman scattering of a quantum probe field

We study the multiorder coherent Raman scattering of a quantum probe field in a far-off-resonance medium with a prepared coherence. Under the conditions of negligible dispersion and limited bandwidth, we derive a Bessel-function solution for the sideband field operators. We analytically and numerically calculate various quantum statistical characteristics of the sideband fields. We show that the multiorder coherent Raman process can replicate the statistical properties of a single-mode quantum probe field into a broad comb of generated Raman sidebands. We also study the mixing and modulation of photon statistical properties in the case of two-mode input. We show that the prepared Raman coherence and the medium length can be used as control parameters to switch a sideband field from one type of photon statistics to another type, or from a non-squeezed state to a squeezed state and vice versa.Comment: 12 pages, 7 figures, to be published in Phys. Rev.

Generation of entangled coherent states via cross phase modulation in a double electromagnetically induced transparency regime

The generation of an entangled coherent state is one of the most important ingredients of quantum information processing using coherent states. Recently, numerous schemes to achieve this task have been proposed. In order to generate travelling-wave entangled coherent states, cross phase modulation, optimized by optical Kerr effect enhancement in a dense medium in an electromagnetically induced transparency (EIT) regime, seems to be very promising. In this scenario, we propose a fully quantized model of a double-EIT scheme recently proposed [D. Petrosyan and G. Kurizki, {\sl Phys. Rev. A} {\bf 65}, 33833 (2002)]: the quantization step is performed adopting a fully Hamiltonian approach. This allows us to write effective equations of motion for two interacting quantum fields of light that show how the dynamics of one field depends on the photon-number operator of the other. The preparation of a Schr\"odinger cat state, which is a superposition of two distinct coherent states, is briefly exposed. This is based on non-linear interaction via double-EIT of two light fields (initially prepared in coherent states) and on a detection step performed using a $50:50$ beam splitter and two photodetectors. In order to show the entanglement of a generated entangled coherent state, we suggest to measure the joint quadrature variance of the field. We show that the entangled coherent states satisfy the sufficient condition for entanglement based on quadrature variance measurement. We also show how robust our scheme is against a low detection efficiency of homodyne detectors.Comment: 15 pages, 9 figures; extensively revised version; added Section