The use of geoscience methods for aquatic forensic searches

There have been few publications on the forensic search of water and fewer still on the use of geoforensic techniques when exploring aqueous environments. Here we consider what the nature of the aqueous environment is, what the forensic target(s) may be, update the geoforensic search assets we may use in light of these, and provide a search strategy that includes multiple exploration assets. Some of the good practice involved in terrestrial searches has not been applied to water to-date, water being seen as homogenous and without the complexity of solid ground: this is incorrect and a full desktop study prior to searching, with prioritized areas, is recommended. Much experimental work on the decay of human remains is focused on terrestrial surface deposition or burial, with less known about the nature of this target in water, something which is expanded upon here, in order to deploy the most appropriate geoforensic method in water-based detection. We include case studies where detecting other forensic targets have been searched for; from metal (guns, knives) to those of a non-metallic nature, such as submerged barrels/packages of explosives, drugs, contraband and items that cause environmental pollution. A combination of the consideration of the environment, the target(s), and both modern and traditional search devices, leads to a preliminary aqueous search strategy for forensic targets. With further experimental research and criminal/humanitarian casework, this strategy will continue to evolve and improve our detection of forensic targets

Widening ROBDDs with Prime Implicants: 12th International Conference, TACAS 2006, Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2006, Vienna, Austria, March 25 - April 2, 2006. Proceedings

Despite the ubiquity of ROBDDs in program analysis, and extensive literature on ROBDD minimisation, there is a dearth of work on approximating ROBDDs. The need for approximation arises because many ROBDD operations result in an ROBDD whose size is quadratic in the size of the inputs. Furthermore, if ROBDDs are used in abstract interpretation, the running time of the analysis is related not only to the complexity of the individual ROBDD operations but also the number of operations applied. The number of operations is, in turn, constrained by the number of times a Boolean function can be weakened before stability is achieved. This paper proposes a widening that can be used to both constrain the size of an ROBDD and also ensure that the number of times that it is weakened is bounded by some given constant. The widening can be used to either systematically approximate from above (i.e. derive a weaker function) or below (i.e. infer a stronger function)

Masonry units bound with waste vegetable oil – Chemical analysis and evaluation of engineering properties

Masonry units with attractive environmental credentials can be produced from waste aggregate materials and vegetable oils. Heat curing at low temperatures induces chemical changes in the binder which stiffen the block and afford them a compressive strength which can be compared to existing blocks and bricks. This method allows use of 100% waste materials, which far exceeds the level of replacement possible in traditional concrete and clay matrices. To better understand the chemistry of the vegetable oil binder at different stages of the curing process a range of experiments have been performed including infrared spectroscopy, liquid chromatography and mass spectrometry. Results show production of chain-shortened and oxygenated derivatives and the nature of reactions based on curing time and physical environment of the binder. Compressive strength and mass loss are dependent on curing time and the altered molecular architecture of the oil, but other physical properties are independent of the chemistry and reliant on physical concerns such as aggregate selection

Differential contributions of set-shifting and monitoring to dual-task interference

It is commonly argued that complex behaviour is regulated by a number of “executive functions” which work to co-ordinate the operation of disparate cognitive systems in the service of an overall goal. However, the identity, roles, and interactions of specific putative executive functions remain contentious, even within widely accepted tests of executive function. The authors present two experiments that use dual-task interference to provide further support for multiple distinct executive functions and to establish the differential contributions of those functions in two relatively complex executive tasks – Random Generation and the Wisconsin Card Sorting Test. Results are interpreted in terms of process models of the complex executive tasks