Construction and Preliminary Performance of Reedbed Treatment Systems at Castle Espie Wildfowl and Wetlands Trust Centre, Northern Ireland

In 1993, the Wildfowl and Wetlands Trust constructed a demonstration reedbed treatment system at its Castle Espie Visitor Centre in Northern Ireland. The objectives of the project included (a) the treatment of septic-tank effluent, (b) the protection of water quality in Strangford Lough, and (c) the establishment of a research base for constructed wetland systems. Parallel beds of equally sized sub-surface and surface flow were constructed and planted, and a research project was initiated to provide data on performance.     

An optimality criteria based method for discrete design optimization taking into account buildability constraints

This paper presents a heuristic design optimization method specifically developed for practicing structural engineers. Practical design optimization problems are often governed by buildability constraints. The majority of optimization methods that have recently been proposed for design optimization under buildability constraints are based on evolutionary computing. While these methods are generally easy to implement, they require a large number of function evaluations (finite element analyses), and they involve algorithmic parameters that require careful tuning. As a consequence, both the computation time and the engineering time are high. The discrete design optimization algorithm presented in this paper is based on the optimality criteria method for continuous optimization. It is faster than an evolutionary algorithm and it is free of tuning parameters. The algorithm is successfully applied to two classical benchmark problems (the design of a ten-bar truss and an eight-story frame) and to a practical truss design optimization problem.     

Framework for Assessing Robotic Dexterity within Flexible Manufacturing

With growing demand for flexibility in manufacturing processes, interest in dexterous industrial robots is increasing. To facilitate benchmarking, and to assess the suitability of these robots for flexible manufacturing tasks, there is a need to develop new methods of capturing the relevant performance characteristics of industrial robots. This research aims to show that the Boothroyd-Dewhurst (B-D) Design-For-Assembly method, an established method for optimizing manufacturing processes, can be effectively adopted to form the basis of a comprehensive robotic dexterity assessment within flexible manufacturing. A comparative study is conducted which shows that the B-D classification tables offer the most comprehensive solution due to the range of operations and artifacts considered. Building on these tables, a framework is developed for determining the suitability of a robot system within flexible manufacturing operations. In a sample test-case scenario involving a pick-and-place operation, the framework is shown to produce an accurate estimate of robot performance that can be easily compared to human data. The framework establishes a link between manufacturing operations and robot performance metrics, which addresses the current difficulty in robot integration and highlights the framework’s potential for adoption within flexible manufacturing.     

Combinatorial Search for Quaternary Methanol Tolerant Oxygen Electro‐Reduction Catalyst

A combinatorial library containing 645 different compositions was synthesised and characterised for methanol tolerant oxygen electro‐reduction reaction (ORR) catalytic performance. The library was composed of compositions involving between 1 and 4 metals among Pt, Ru, Fe, Mo and Se. In an optical screening test, Pt(50)Ru(10)Fe(20)Se(10) composition exhibited the highest ORR activity in the presence of methanol. This composition was further investigated by synthesis and characterisation of a powder version catalyst [Pt(50)Ru(10)Fe(20)Se(10)/C]. At 0.85 V [vs. reversible hydrogen electrode (RHE)] in the absence of methanol, the Pt/C catalyst exhibited higher ORR current (0.0990 mA) than the Pt(50)Ru(10)Fe(20)Se(10)/C catalyst (0.0902 mA). But much higher specific activity (12.7 μA cm_pt^–2) was observed in the Pt(50)Ru(10)Fe(20)Se(10)/C catalyst than for the Pt/C catalyst 6.51 μA cm_pt^–2). In the presence of methanol, the ORR current decreased by 0.0343 and 0.247 mA for the Pt(50)Ru(10)Fe(20)Se(10)/C and Pt/C catalysts, respectively, which proved the excellent methanol tolerance of the Pt(50)Ru(10)Fe(20)Se(10)/C catalyst.     

Prediction of enteric methane output from milk fatty acid concentrations and rumen fermentation parameters in dairy cows fed sunflower, flax, or canola seeds

Milk fatty acid (FA) composition has been suggested as a means of predicting enteric methane (CH₄) output in lactating dairy cattle because of the common biochemical pathways among CH₄, acetate, and butyrate in the rumen. Sixteen lactating Holstein cows were used in a Latin square design with four 28-d periods. All diets contained steam-rolled barley, a pelleted supplement, barley silage [45% of dietary dry matter (DM)] and 3.3% added fat (DM basis) from 1 of 4 sources: calcium salts of long-chain FA (palm oil; control) or crushed oilseeds from sunflower, flax, or canola. The objectives of this study were to (1) compare the effect of diets on milk FA profile; (2) model CH₄ production from milk FA composition, intake, and rumen fermentation variables; and (3) test the applicability of CH₄ prediction equations reported in previous studies. Methane (g/d) was measured in chambers (2 animals/chamber) on 3 consecutive days (d 21–23). The test variables included total DM intake (DMI, kg/d; d 21–23), forage DMI (kg/d; d 21–23), milk yield (kg/d; d 21–23), milk components (d 18–21), milk FA composition (% total FA methyl esters; d 18–21), rumen volatile FA (mol/100 mol; d 19–21), and protozoal counts (d 19–21), and were averaged by chamber and period to determine relationships between CH₄ and the test variables. Milk trans(t)10-, t11-18:1, and cis(c)9t11-18:2 were greater for sunflower seeds compared with the other diets. Forage DMI (correlation coefficient, r = 0.52; n = 32), DMI (r = 0.52; n = 32), and rumen acetate + butyrate:propionate (r = 0.72; n = 16) were positively related to CH₄ (g/d), whereas rumen propionate (r = 0.63; n = 16), milk c9-17:1 (r = 0.64; n = 32), and c11-18:1 (r = 0.64; n = 32) were negatively related to CH₄. The best regression equation (coefficient of determination = 0.90; n = 16) was CH₄ (g/d) = −910.8 (±156.7) × milk c9-17:1 + 331.2 (±88.8) × milk 16:0 iso + 0.0001 (±0.00) × total entodiniomorphs + 242.5 (±39.7). Removing rumen parameters from the model also resulted in a reasonably good estimate (coefficient of determination = 0.83; n = 32) of CH₄. Stepwise regression analysis within diets resulted in greater coefficient of determination and lower standard error values. Predictions of CH₄, using equations from previous studies for the data set from this study, resulted in a mean overestimation ranging from 19 to 61% across studies. Thus, milk FA alone may not be suitable for developing universal CH₄ prediction equations.     

Treatment of intrahepatic cancers with radiation doses based on a normal tissue complication probability model

PURPOSE: To attempt to safely escalate the dose of radiation for patients with intrahepatic cancer, we designed a protocol in which each patient received the maximum possible dose while being subjected to a 10% risk of radiation-induced liver disease (RILD, or radiation hepatitis) based on a normal tissue complication probability (NTCP) model. We had two hypotheses: H1; with this approach, we could safely deliver higher doses of radiation than we would have prescribed based on our previous protocol, and H2; the model would predict the observed complication probability (10%). PATIENTS AND METHODS: Patients with either primary hepatobiliary cancer or colorectal cancer metastatic to the liver and normal liver function were eligible. We used an NTCP model with parameters calculated from our previous patient data to prescribe a dose that subjected each patient to a 10% complication risk within the model. Treatment was delivered with concurrent hepatic arterial fluorodeoxyuridine (HA FUdR). Patients were evaluated for RILD 2 and 4 months after the completion of treatment. RESULTS: Twenty-one patients completed treatment and were followed up for at least 3 months. The mean dose delivered by the current protocol was 56.6 +/- 2.31 Gy (range, 40.5 to 81 Gy). This dose was significantly greater than the dose that would have been prescribed by the previous protocol (46.0 +/- 1.65 Gy; range, 33 to 66 Gy; P < .01). These data are consistent with H1. One of 21 patients developed RILD. The complication rate of 4.8% (95% confidence interval, 0% to 23.8%) did not differ significantly from the predicted 8.8% NTCP (based on dose delivered) and excluded a 25% true incidence rate (P < .05). This finding supports H2. CONCLUSION: Our results suggest that an NTCP model can be used prospectively to safely deliver far greater doses of radiation for patients with intrahepatic cancer than with previous approaches. Although the observed complication probability is within the confidence intervals of our model, it is possible that this model overestimates the risk of complication and that further dose escalation will be possible. Additional follow-up and accrual will be required to determine if these higher doses produce further improvements in response and survival.     

Improved Flux Pinning in Melt-Textured YBa2Cu3O7 − δ and ErBa2Cu3O7 − δ Through Chemical Additions

The effects of Ce-based additions (CeO₂ and BaCeO₃) in combination with MgO additions on the magnetic properties of melt-textured YBa₂Cu₃O_{7 ? δ} and ErBa₂Cu₃O_{7 ? δ} have been investigated. The additions lead to improvements in the magnetic properties of both RE-123 compounds compared to samples with either addition alone or with no additions. The Ce–Mg addition combination produces a “peak effect” in the magnetic hysteresis loop without significant T _c degradation. This is postulated to be due to the formation of a new type of pinning center. Both Ce and Mg ions are thought to substitute in the RE-Ba₂Cu₃O_{7 ? δ} lattice, creating defects that produce a “peak effect” in the magnetic hysteresis loop. Mg additions alone lead to a reduced T _c, while Ce additions restore the T _c and enhance the magnitude of the peak.