Development and Evaluation of a Nanoparticle Generator for Human Inhalation Studies with Airborne Zinc Oxide

In the EU there is an increasing need for regulatory agencies to derive health based threshold limits based on human inhalation studies with airborne particles. A necessary prerequisite for such projects is the development of a suitable generator system to produce nanoparticle test aerosols for human whole-body inhalation studies. We decided to use a generator with flame-based heating of aqueous precursor solutions. Validation of the test system was done by generating zinc oxide (ZnO) nanoparticles with minimal contamination of trace gases, i.e., nitric oxides or carbon monoxide that could confound the effects seen in exposed subjects. ZnO was selected based on the uncertainties surrounding its health effects after exposure at the workplace. The generation process of the developed flame generator yields ZnO nanoparticles with monomodal size distribution and very good temporal stability. The maximum target exposure mass concentration of 2 mg/m³ ZnO, with a resulting median particle diameter of 57 nm, is attainable in our human exposure laboratory. The morphological examination shows typical agglomerates and aggregates formed by high temperature processes. Overall, the performed experiments confirm that a constant exposure can be provided for all subjects at all times.

Copyright 2014 American Association for Aerosol Research     

Surveillance for the masses: the political and legal landscape of the UK Investigatory Powers Bill

In March 2016, the UK Government put the Investigatory Powers Bill before Parliament. The new law, if enacted, will considerably increase the powers of law enforcement and security services regarding mass data retention, mass surveillance and mass hacking. This raises considerable concerns not just about the content of the Bill and its impact on privacy, but also about the method of its enactment and the ever diminishing parliamentary and judicial scrutiny of surveillance legislation in the UK.     

Experimental and numerical analysis of the influence of cable tray arrangements on the resulting mass loss rate and fire spreading

In the context of industrial buildings and power plants, electrical installations and cable trays represent a main fuel load and a potential initial fire source due to possible short circuits or comparable malfunction. Furthermore, a fire can spread from one tray to additional trays mounted above and/or horizontally on one tray. Because of the high significance of cable fires, several research projects have been carried out, investigating the fire behaviour of cables from small‐scale tests, eg, the cone calorimeter, up to large‐scale tests, analysing complete cable tray constructions. The goal of the work presented in this paper is the extension of the knowledge regarding the influence of geometrical parameters like the packing density and tray distance on the burning behaviour and fire spread of cable tray installations. The results are considered, together with test results from the literature, to quantify the main physical parameters describing the burning behaviour. In a next step, the general applicability of these parameters as input data for the parametrization of the source term of numerical simulations is shown. The test results show that the burning behaviour and the fire spreading highly depend on the cable arrangement of the cables on the cable tray, in combination with other boundary conditions. By applying the results as input for a fire simulation, the mass loss rate is considered appropriately.     

Genome-Wide Investigation of Multifocal and Unifocal Prostate Cancer—Are They Genetically Different?

Prostate cancer is widely observed to be biologically heterogeneous. Its heterogeneity is manifested histologically as multifocal prostate cancer, which is observed more frequently than unifocal prostate cancer. The clinical and prognostic significance of either focal cancer type is not fully established. To investigate prostate cancer heterogeneity, the genetic profiles of multifocal and unifocal prostate cancers were compared. Here, we report observations deduced from tumor-tumor comparison of copy number alteration data of both focal categories. Forty-one fresh frozen prostate cancer foci from 14 multifocal prostate cancers and eight unifocal prostate cancers were subjected to copy number variation analysis with the Affymetrix SNP 6.0 microarray tool. With the investigated cases, tumors obtained from a single prostate exhibited different genetic profiles of variable degrees. Further comparison identified no distinct genetic pattern or signatures specific to multifocal or unifocal prostate cancer. Our findings suggest that samples obtained from multiple sites of a single unifocal prostate cancer show as much genetic heterogeneity and variability as separate tumors obtained from a single multifocal prostate cancer.     

Reconfigurable handling system

The demand for more versatile assembly and handling systems to facilitate customized production is gaining in importance, especially with regard to the constantly-increasing cost pressure, to expansion of the range of product versions and the shortening of innovation cycles. As a cost-effective approach for frequently changing assembly tasks, a novel manipulation concept has been developed by combining given robot technologies. This new handling system has a modular and adaptable layout, which consists of several mobile arms to manipulate the object in six-dimensional Cartesian space. After grasping, when the arms are attached to the object, the mechanical architecture is similar to parallel manipulators or cooperating robots. As the mounting and gripping points of the arms can easily be changed, the manipulator can be reconfigured so as to match the user’s preferences and needs. In addition to the kinematic adaption the regarding task, the hardware and new functions can be reconfigured as well. Contact elements, measurement and assembly devices as well as testing modules can easily be in integrated in the concept. A modular automatic control concept combined with a self-optimizing planning tool helps the user to find the optimal configuration and realize it in an economic way.     

Computing Nash Equilibria for Scheduling on Restricted Parallel Links

We consider the problem of routing n users on m parallel links under the restriction that each user may only be routed on a link from a certain set of allowed links for the user. So, this problem is equivalent to the correspondingly restricted scheduling problem of assigning n jobs to m parallel machines. In a Nash equilibrium, no user may improve its own Individual Cost (latency) by unilaterally switching to another link from its set of allowed links.