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.     

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     

Design of reflectors which will distribute sunlight in a specified manner

A differential equation is obtained for the shape of a reflecting surface which will distribute axially symmetric light intensity into a specified irradiance over a receiver surface which is symmetric about the direction of the incident light. Results are applied to the design of rotationally symmetric solar reflectors and also to a 2-dimensional geometry, that is one in which the reflector is a cylinder with its axis perpendicular to the incident beam. The procedure is used to numerically calculate the shape of reflectors which will uniformly concentrate collimated light and also light from a point source over a flat receiver surface. Results are also applied to determine the shape of a reflector which will distribute collimated light uniformly over the surface of a cylinder and also over a sphere.     

On the cost of uniform protocols whose memory consumption is adaptive to interval contention

Recently, we introduced a novel term, memory-adaptive, whose goal it is to capture what it means for a distributed protocol to most efficiently make use of its shared memory. We proved three results that relate to the memory-adaptive model in the uniform setting. We considered a store/release protocol where processes are required to store a value in shared MWMR memory so that it cannot be overwritten until it has been released by the process. We showed that there do not exist uniformly wait-free store/release protocols using only the basic operations read and write that are memory-adaptive to point contention. We further showed that there exists a uniformly wait-free store/release protocol using only the basic operations read, write, and read-modify-write that is memory-adaptive to interval contention and time-adaptive to total contention. This left a significant gap — it remained open as to whether there exists a uniform, memory adaptive to interval contention store/release protocol that only uses read/write (no read-modify-write) registers. In this paper, we close this gap by showing that no such protocol can exist. We furthermore illustrate the validity and practicality of the concept of memory adaptiveness by providing a uniform, memory-adaptive to interval contention store/release protocol for Network Attached Disks.     

Differential interference contrast x-ray microscopy with twin zone plates

X-ray imaging in differential interference contrast (DIC) with submicrometer optical resolution was performed by using a twin zone plate (TZP) setup generating focal spots closely spaced within the TZP spatial resolution of 160 nm. Optical path differences introduced by the sample are recorded by a CCD camera in a standard full-field imaging and by an aperture photodiode in a standard scanning transmission x-ray microscope. Applying this x-ray DIC technique, we demonstrate for both the full-field imaging and scanning x-ray microscope methods a drastic increase in image contrast (approximately 20x) for a low-absorbing specimen, similar to the Nomarski DIC method for visible-light microscopy.