Initial geological considerations before installing ground source heat pump systems

The performance of an open- or closed-loop ground source heat pump system depends on local geological conditions. It is important that these are determined as accurately as possible when designing a system, to maximize efficiency and minimize installation costs. Factors that need to be considered are surface temperature, subsurface temperatures down to 100–200 m, thermal conductivities and diffusivities of the soil and rock layers, groundwater levels and flows, and aquifer properties. In addition, rock strength is a critical factor in determining the excavation or drilling method required at a site and the associated costs. The key to determining all of these factors is an accurate conceptual site-scale model of the ground conditions (soils, geology, thermogeology, engineering geology and hydrogeology). The British Geological Survey has used the modern digital geological mapping of the UK as a base onto which appropriate attributes can be assigned. As a result it is possible to generate regional maps of surface and subsurface temperatures, rock strength and depth to water. This information can be used by designers, planners and installers of ground source heat pump systems. The use of appropriate geological factors will assist in creating a system that meets the heating or cooling load of the building without unnecessary overengineering

Silenes: novel synthetic reagents for olefin functionalisation

Silenes, compounds containing silicon-carbon double bonds, have been subject to much theoretical interest over the past 25 years. However, despite their high reactivity, to date there have been no reports of the attempted use of silenes as synthetic reagents. Silenes have been formed by the thermolysis of acyltris(trimethylsilyl)silanes, which have been found to react with dienes to give Diels-Alder cycloadducts in good yield. Further to this, it has been found that silene dimers, formed by the photolysis of acyltris(trimethylsilyl)silanes, have been found to revert to give silenes at much lower temperatures. These dimers have been found to be excellent low-temperature silene sources. The reactions of acyltris(trmiethylsilyl)silanes with silyl Lewis acids have been found to give novel products in excellent yield, via a series of migration reactions. These migrations are believed to involve the formation of a silyl cation or "silylenium" ion intermediate. Furthermore, the reaction with trimethylsilyl triflate is believed to proceed via the formation of a silene intermediate, the existence of which has been supported by trapping with methanol. Finally, the oxidation of silene cycloadducts has been attempted, using established conditions. The first series of silene cycloadducts obtained were found to be unreactive towards oxidation. However, the reaction of a silene, formed by a Peterson elimination process, with dienes has been found to give a cycloadduct as a single diastereoisomer. It has been shown that this cycloadduct can be oxidised, following established protocols, to give either a homoallylic alcohol or 1,5-diol in reasonable overall yield. This result provides evidence for the utility of silenes as reagents for functionalising dienes

Major eastern wheatbelt soils to characterise soil moisture availability

In the Eastern Wheatbelt of Western Australia, there are seven major soil groups (acid sands, good soilplain soils, gravelly sands, duplex soils, medium-heavy soils, heavy non-friable soils and heavy friable soils. This report considers the ability of various soils to store or retain water in an attempt to partially determine the yield potential of crops

Information retrieval in the workplace: A comparison of professional search practices

Legal researchers, recruitment professionals, healthcare information professionals, and patent analysts all undertake work tasks where search forms a core part of their duties. In these instances, the search task is often complex and time-consuming and requires specialist expertise to identify relevant documents and insights within large domain-specific repositories and collections. Several studies have been made investigating the search practices of professionals such as these, but few have attempted to directly compare their professional practices and so it remains unclear to what extent insights and approaches from one domain can be applied to another. In this paper we describe the results of a survey of a purposive sample of 108 legal researchers, 64 recruitment professionals and 107 healthcare information professionals. Their responses are compared with results from a previous survey of 81 patent analysts. The survey investigated their search practices and preferences, the types of functionality they value, and their requirements for future information retrieval systems. The results reveal that these professions share many fundamental needs and face similar challenges. In particular a continuing preference to formulate queries as Boolean expressions, the need to manage, organise and re-use search strategies and results and an ambivalence toward the use of relevance ranking. The results stress the importance of recall and coverage for the healthcare and patent professionals, while precision and recency were more important to the legal and recruitment professionals. The results also highlight the need to ensure that search systems give confidence to the professional searcher and so trust, explainability and accountability remains a significant challenge when developing such systems. The findings suggest that translational research between the different areas could benefit professionals across domains

A Search for DDT Residues in the Juneau Icefield, Alaska

The objectives of this study were: 1) to determine if DDT residues occurred in the ice of the Juneau Icefield, and 2) to devise a simple, inexpensive method of sampling glacial ice for pesticide residues. No DDT was found in the samples of ice collected strata spanning the 1963 to 1970 period. However, phthalate plasticizers were found in all samples and were assumed to be· due to contamination during collection. The elution time of the phthalate by gas chromatography was identical to that of p, p-DDT. Conversion of DDT to DDD by ultraviolet light was found to remove the phthalate. In the presence of phthalate, DDT could be verified at 25 x 10 -12g per gram of water. In the absence of phthalate the lower of detection of DDT was 1 x 10-12gfg water

Peak power output in the bench pull is maximised after 4 weeks of specific power training

Maximal power production has been shown to be a differentiating factor between playing levels in many sports and is thus a focus of many strength and conditioning programmes. We sought to evaluate the duration for which a strategy of training with the optimal load (that maximises power output) will be effective in producing improvements in power output in the bench pull. The optimal load that produced the maximum power output in the bench pull was determined for twenty-one male university athletes who were randomly assigned to a group that trained with their optimal load or a load 10% of their one repetition maximum below the optimal load. Both groups completed two sessions per week for 4 weeks, after which their power output capabilities were reassessed. They then trained for a further 3 weeks with a load that was modified to reflect changes in their optimal load. The cohort as a whole had improved their peak power output by 4.6% (p = 0.002, d = 0.290) after 4 weeks of training, but experienced no further increase after another 3 weeks of training. There were no significant differences in the response to training between the two groups. This study suggests that improvements in power output can be realised within a few weeks when training with the optimal load, but training in such a way for a longer duration may be ineffective. Strength and conditioning coaches should consider periodizing power training to maximise gains in power output capabilities