Sub-barrier Coulomb effects on the interference pattern in tunneling ionization photoelectron spectra

We use a quantum trajectory-based semi-classical method to account for Coulomb interaction between the photoelectron and the parent ion in the classically forbidden, sub-barrier region during strong-field tunneling ionization processes. We show that---besides the well-known modification of the tunneling ionization probability---there is also an influence on the interference pattern in the photoelectron spectra. In the long-wavelength limit, the shift of the intra-cycle interference fringes caused by sub-barrier Coulomb effects in the laser polarization direction can be derived analytically. We compare our results with \emph{ab initio} solutions of the time-dependent Schr\"odinger equation and find good agreement in the long-wavelength regime, whereas the standard strong field approximation fails. We show that the nodal structure along low-order above-threshold ionization rings is also affected by sub-barrier Coulomb effects.Comment: 10 pages, 4 figures, RevTe

Developing modular product family using GeMoCURE within an SME

Companies adopt the strategy of producing variety of products to be competitive and responsive to market. Product variation is becoming an important factor in companies' ability to accurately meet customer requirements. Ever increasing consumer options mean that customers have more choices than ever before which put commercial pressures on companies to continue to diversify. This can be a particular problem within Small to Medium Enterprises (SMEs) who do not always have the level of resources to meet these requirements. As such, methods are required that provide means for companies to be able to produce a wide range of products at the lowest cost and shortest time. This paper details a new modular product design methodology that provides a focus on developing modular product families. The methodology's function is described and a case study detailed of how it was used within an SME to define the company's product portfolio and create a new Generic Product Function Structure from which a new family of product variants can be developed. The methodology lends itself to modular re-use which has the potential to support rapid development and configuration of product variants

Application of context knowledge in supporting conceptual design decision making

Conceptual design is the most important phase of the product life cycle as the decisions taken at conceptual design stage affect the downstream phases (manufacture, assembly, use, maintenance, and disposal) in terms of cost, quality and function performed by the product. This research takes a holistic view by incorporating the knowledge related to the whole context (from the viewpoint of product, user, product's life cycle and environment in which the product operates) of a design problem for the consideration of the designer to make an informed decision making at the conceptual design stage. The design context knowledge comprising knowledge from these different viewpoints is formalised and a new model and corresponding computational framework is proposed to support conceptual design decision making using this formalised context knowledge. Using a case study, this paper shows the proof of the concept by selecting one concept among different design alternatives using design context knowledge thereby proactively supporting conceptual design decision making for an informed and effective decision making