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Design Margins: Impact on Building Energy Performance
This paper examines the addition of design margins for building services energy infrastructure during the design process. It argues that care must be taken when applying margins; ensuring cumulative effects do not undermine the ability of systems to be energy efficient. An example of a hospital Trust is provided showing the addition of design margins impacting the energy efficiency of services provided. Tensions are found between delivery of flexibility, adaptability and other change parameters and the need for the system to be bounded, so as to encourage effectiveness
Review of methods for deriving areal reduction factors
The design of hydraulic structures requires knowledge of how much rain is likely to fall within a certain amount of time, and over a specific area. Point rainfalls are only representative for a very limited area, and for larger areas the areal average rainfall depth is likely to be much smaller than at the point of maximum observed depth. The estimation of areal reduction factors is concerned with the relationship between the point and areal rainfalls. This relationship has been found to vary with, for example, predominant weather type, season and return period. Methods for estimation of areal reduction factors include empirical and analytical methods. The current design guidelines in the United Kingdom are based on an empirical method, but since they were issued in 1975, several new analytical methods have been proposed. These methods are discussed, and recommendations for an update suitable for United Kingdom conditions are made
Rainfall-runoff and other modelling for ungauged/low-benefit locations: Operational Guidelines
Efficient and automatic methods for flexible regression on spatiotemporal data, with applications to groundwater monitoring
Fitting statistical models to spatiotemporal data requires finding the right balance between imposing smoothness and following the data. In the context of P-splines, we propose a Bayesian framework for choosing the smoothing parameter which allows the construction of fully-automatic data-driven methods for fitting flexible models to spatiotemporal data. An implementation, which is highly computationally efficient and which exploits the sparsity of the design and penalty matrices, is proposed. The findings are illustrated using a simulation study and two examples, all concerned with the modelling of contaminants in groundwater. This suggests that the proposed strategy is more stable that competing methods based on the use of criteria such as GCV and AIC
Role of microalgae in conditioning water in penaeid larval culture
Microalgae play an important role in conditioning water quality for penaeid larval culture. Recently it has been demonstrated that a modification of the green water larval culture system (Ling, 1969) for Macrobrachium allows the production of post larvae without any water change, despite extensive use of artificial feeds (Ang and Cheah, 1986). Increase of toxic metabolites such as ammonia and nitride are also common in penaeid larval culture, especially where excessive amounts of artifial feeds are employed. Present work examines the use of six marine microalgae at four cell concentrations as a "biological filter" system, to control and detoxify levels of ammonia and nitrite in P. monodon larval culture water whilst using artificial diet. Preliminary results indicate that amongst the six algal species tested, C. japonica at 1000 cell μlˉ¹ was most effective in reducing accumulated toxic metabolites from an unchanged culture water environment
A critique of avian CHD-based molecular sexing protocols illustrated by a Z-chromosome polymorphism detected in auklets
The sexes of non-ratite birds can be determined routinely by PCR amplification of the CHD-Z and CHD-W genes.
CHD -based molecular sexing of four species of auklets revealed the presence of a polymorphism in the Z chromosome. No deviation from a 1:1 sex ratio was observed among the chicks, though the analyses were of limited power. Polymorphism in the CHD-Z
gene has not been reported previously in any bird, but if undetected it could lead to the incorrect assignment of sex. We discuss the potential difficulties caused by a
polymorphism such as that identified in auklets and the merits of alternative CHD -based sexing protocols and primers
Calibration of the Large Solid Angle Detector
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Deriving the ideal ore texture for microwave treatment of metalliferous ores
High power density microwave treatments on metalliferous ores have historically been shown to reduce ore competency prior to beneficiation at economically feasible energy inputs. However, the relationship between mineralogical textural features and the extent of the microwave-induced fracturing had previously been limited to qualitative descriptions or simplistic two-phase numerical models, which could not account for the complex mineral assemblages in real ores. In this paper, mineralogy, grain size, dissemination, textural consistency and mineral associations were determined for 13 commercially exploited nickel, copper and lead-zinc ores using a Mineral Liberation Analyser (MLA). The ores were subjected to high power density microwave treatments at up to 25kW in a single mode cavity with microwave energy inputs of approximately 0.5-10kWh/t, and the subsequent reductions in ore competency were measured by the Point Load Test. The ores that demonstrated the greatest reductions in strength typically contained between approximately 2%wt to 20%wt of highly microwave-absorbing minerals, with a native grain size d50 greater than approximately 500µm, constrained by hard matrix minerals such as quartz and feldspar. Texturally consistent ores with a high proportion of amenable textures also demonstrated the highest average reductions in strength. These findings support the qualitative descriptions and numerical modelling results available in the literature and provide a baseline for selecting likely candidate ores for microwave treatments in the future
Increasing the grind size for effective liberation and flotation of a porphyry copper ore by microwave treatment
In this paper, mineralogy, grain size, dissemination, textural consistency and mineral associations were determined for a commercially exploited porphyry copper ore using a Mineral Liberation Analyser (MLA). The ore was subjected to high power density microwave treatments in a single mode cavity at 15 kW and approximately 2 kW h/t. The untreated and microwave-treated samples were subsequently milled to two grind sizes near the nominal plant grind size and a size-by-liberation analysis performed. The analysis revealed that equivalent liberation could be obtained at a grind size approximately 50–60 μm coarser than the nominal plant grind due to the microwave treatment. Flotation testing indicated that an increase in copper recovery of approximately 1% could be achieved, or that a grind size increase of approximately 30 μm may potentially yield equivalent copper recovery due to the microwave-enhanced liberation observed. However, statistical analyses demonstrated that it is difficult to attain confidence in recovery increases of approximately 1% even when conducting batch flotation tests in triplicate. The ore under investigation had previously been shown to produce only modest average reductions in strength (∼8%) under similar microwave treatment conditions due to a prevalence of many unfavourable textures. However, the preferential association of copper minerals with a hard matrix mineral (quartz) and a hard microwave-absorbent mineral (pyrite) resulted in a significant change in liberation behaviour
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