Radiocarbon dating of deep-sea corals

Deep-sea corals are a promising new archive of paleoclimate. Coupled radiocarbon and U-series dates allow ^(14)C to be used as a tracer of ocean circulation rate in the same manner as it is used in the modern ocean. Diagnetic alteration of coral skeletons on the seafloor requires a thorough cleaning of contaminating phases of carbon. In addition, 10% of the coral must be chemically leached prior to dissolution to remove adsorbed modern CO_2. A survey of modern samples from the full Δ^(14)C gradient in the deep ocean demonstrates that the coralline CaCO_3 records the radiocarbon value of the dissolved inorganic carbon

Effectiveness of using phase change materials on reducing summer overheating issues in UK residential buildings with identification of influential factors

The UK is currently suffering great overheating issues in summer, especially in residential buildings where no air-conditioning has been installed. This overheating will seriously affect people’s comfort and even health, especially for elderly people. Phase change materials (PCMs) have been considered as a useful passive method, which absorb excessive heat when the room is hot and release the stored heat when the room is cool. This research has adopted a simulation method in Design Builder to evaluate the effectiveness of using PCMs to reduce the overheating issues in UK residential applications and has analyzed potential factors that will influence the effectiveness of overheating. The factors include environment-related (location of the building, global warming/climate change) and construction-related (location of the PCM, insulation, heavyweight/lightweight construction). This research provides useful evidence about using PCMs in UK residential applications and the results are helpful for architects and engineers to decide when and where to use PCMs in buildings to maintain a low carbon lifestyle

Occupant adaptive behaviour: an effective method towards energy efficient buildings

Energy efficient buildings play an important role in achieving a sustainable society. Conventional methods achieving energy efficient buildings mainly focus on upgrading the physical properties of the building, such as increasing their thermal insulations, neglecting the occupants who are using the building. This study justifies the potential contribution of a new method, i.e. selecting offices for occupants with a consideration of their behavioural preferences and the building’s physical properties, to the building’s energy efficiency. Dynamic building performance simulation has been adopted for the justification, based on a case study building with a simple rectangular shape. The occupant window behavioural model was developed from field measured data in an office building and the up-to-date stochastic approach was used to predict the state of windows for the simulation. Simulation results clearly reflect that 1) building’s physical properties, such as window orientation, have impact on the thermal performance of the building; 2) occupant behaviour can also affect the thermal performance of the building; and 3) considering both occupant behavioural preference and building’s physical properties can promote building’s thermal performance, without requirement of changing occupant behaviour

Energy waste in buildings due to occupant behaviour

Occupants’ behaviour has a significant impact on the energy performance of buildings. A good understanding of how occupants use a building provides a possibility of promoting the building’s energy efficiency through changing occupant behaviour. Building simulation has been adopted as a useful method by building engineers for quantifying the effects of changing occupant behaviour on the building’s energy consumption and indoor environment. However, due to the lack of real measured data with respect to how occupants use the building, such simulation work has relied on assumed behavioural patterns, which significantly reduces the reliability of the predicted results. This paper describes a longitudinal study monitoring occupants’ heating, window opening and cooling behaviour in an office building throughout summer, transitional and winter periods. These behavioural data were then used to drive dynamic building performance simulation to predict the energy saving potential of changing behaviour. Comparison with predicted results by assumed behavioural patterns reflected that improperly assumed behavioural patterns may either overestimate or underestimate the energy saving potential of changing behaviour, especially for unextreme behaviours

Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char

Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800 °C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures