Neutronic characterization of the MEGAPIE target

The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of about 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). This project is an important step in the roadmap towards the demonstration of the accelerator driven system (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a “mapping” of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment.     

Redox processes in pressurised smoked salmon studied by resonance Raman spectroscopy

Non-thermal food preservation technology is based on the application of high pressures up to 600 MPa. Here we report a resonance Raman (RR) spectroscopic analysis of smoked salmon meat after high pressure processing. High quality spectra, which can be obtained even from packed salmon without spectral interference of the packing foil, allow determining pressure-dependent irreversible changes of the main RR-active components of salmon meat, astaxanthin and myoglobin/haemoglobin. High pressure-treatment causes a decrease of the relative RR intensities of astaxanthin as probed with 514 nm excitation which is in line with a slight attenuation of the originally intense red colour of the salmon meat. 413-nm excited RR spectra indicate a heterogeneous broadening of astaxanthin bands accompanied by the formation of deoxy-myoglobin or deoxy-haemoglobin. The results suggest that pressure-treatment facilitates the oxidative degradation of astaxanthin coupled to the reduction of metmyoglobin (methaemoglobin).     

Facile Fabrication of Ultrafine Copper Nanoparticles in Organic Solvent

A facile chemical reduction method has been developed to fabricate ultrafine copper nanoparticles whose sizes can be controlled down to ca. 1 nm by using poly(N-vinylpyrrolidone) (PVP) as the stabilizer and sodium borohyrdride as the reducing agent in an alkaline ethylene glycol (EG) solvent. Transmission electron microscopy (TEM) results and UV–vis absorption spectra demonstrated that the as-prepared particles were well monodispersed, mostly composed of pure metallic Cu nanocrystals and extremely stable over extended period of simply sealed storage.     

Optima localization by vehicle formations imitating the Nelder-Mead simplex algorithm

In this paper, we address the problem of localizing extrema points and iso-contours of ambient environmental fields (specifically, ocean bottom landscape and underwater plumes) using a networked formation of autonomous underwater vehicles. We propose the use of the Nelder-Mead extension to the basic simplex nonlinear optimization algorithm. In these robust gradient-free strategies, decisions are solely made based on field values measured by the individual vehicles, while measurements are fused and actions decided according to the algorithm. A main goal of this paper is to trigger interest in direct search methods as pertains to this type of robotic problem.     

Guest Editor's Introduction: Capturing Design Knowledge

Capturing software design knowledge is important because it tends to evaporate as software systems evolve. This has severe consequences for many software projects. To counteract this phenomenon, effective, systematic documentation of design knowledge is important. However, many proposed approaches for capturing design knowledge are still experimental or in an early-adoption stage. In this article, we discuss existing and new approaches to deal with parts of the knowledge evaporation problem.     

Six-layer lamination of a new dry film negative-tone photoresist for fabricating complex 3D microfluidic devices

We present a new epoxy-based negative-tone dry film photoresist (DFR) for fabricating multilayer microfluidic devices using a lamination process combined with a standard photolithography technology. As proof-of-concept, a complex 3D-hydrodynamic focusing device was produced via a six-layer lamination process of 33 µm-thick DFR layers. The bonding strength of the new DFR was tested on silicon, glass, and titanium substrates, respectively. A maximum bonding strength of 37 MPa was obtained for the dry film photoresist laminated on glass. No leakage was found, and burst tests proved excellent robustness and sealing reliability of the microchannels.     

Experimental studies for verification of thermal effects in cutting

Investigations on metal-cutting machining processes that were conducted since the second half of the twentieth century have considerably contributed to disclosing the principles underlying the cutting process. Although numerous studies have been carried out on this subject, a generally valid model of the cutting process and the interactions in the separating processes does not exist yet. Such a model could guarantee the disclosure of the principles of thermodynamic interactions between the cutting process and the involved machine structure. This contribution is twofold and presents an experimental setup used to determine cutting forces and temperatures in orthogonal cutting processes. The results are then used as a reference for simulations made with the Discrete Element Method (DEM). The DEM is due to its meshless nature well suited to capture large deformations and rupture of material which is included very naturally. It is examined to which extent the measured results can be captured with the DEM model.     

The Autosar XML Schema and Its Relevance for Autosar Tools

The Autosar standard represents an emerging approach to unifying virtually all aspects of the development workflow of automotive embedded software. The standard features an XML schema used as a basis for interchanging documents containing Autosar model content. Although the schema is primarily for document exchange, it could also be the basis for creating a metamodel. However, a tool metamodel should probably be designed differently.