In situ regeneration of the thermal stabilizer benzyl alcohol via ethanol in simulated jet fuels above 400°C

Ethanol/benzyl alcohol mixtures are effective thermal stabilizers for jet fuels above 400°C. Ethanol, which itself is only a marginal thermal stabilizer, primarily serves to regenerate benzyl alcohol in situ by reducing benzaldehyde, the reaction product formed by the reaction of benzyl alcohol with the hydrocarbon radicals produced at these temperatures. Accordingly, in the presence of ethanol, less benzyl alcohol is necessary to thermally stabilize hydrocarbon fuels under the same conditions of time and temperature.     

Mortars containing wood-based fibres under thermal exposure using cone calorimeter heating

The behaviour of concrete structures under fire can be improved by adding fibers. However, relatively little is known of the details of the possible beneficial features of the fibre addition. The aim of this study was to compare the effects of different wood-based fibres on the thermal properties of a standard laboratory cement mortar at conditions of a developing fire. The cone calorimeter heating method was used, and the sample thickness and heat flux were varied (25 mm or 50 mm, 25 kWm^?2 or 50 kWm^?2) to compare test conditions. The fibres comprised chemical pulp, chemi-thermomechanical pulp, recycled fibres and viscose fibres. The fibre content in the mortar was 0.15–0.5% by weight. Temperature and mass loos measurements of oven-dried specimens (moisture content <0.1%) showed no differences between different wood-based fibre mortars and plain mortar. With increasing moisture content (about 5%), however, the presence of fibres affected the release of moisture from the fibre mortar material. With rapid heating of mortars, which have a moisture content of about 5%, local pressures are easily built up. These pressures are mainly caused by free water vaporization. The rear surface temperature measurements indicate that in mortars containing wood-based fibres (0.15–0.5% by weight) the vaporization temperatures may be 20 –25% lower than in the reference mortar. Some effects on heat transfer can also be observed due to differences in water vaporization and movement processes.     

Antibacterial effect of bioactive glasses on clinically important anaerobic bacteria in vitro

Bioactive glasses (BAGs) of different compositions have been studied for decades for clinical use and they have found many dental and orthopaedic applications. Particulate BAGs have also been shown to have antibacterial properties. This large-scale study shows that two bioactive glass powders (S53P4 and 13–93) and a sol–gel derived material (CaPSiO II) have an antibacterial effect on 17 clinically important anaerobic bacterial species. All the materials tested demonstrated growth inhibition, although the concentration and time needed for the effect varied depending on the BAG. Glass S53P4 had a strong growth-inhibitory effect on all pathogens tested. Glass 13–93 and sol–gel derived material CaPSiO II showed moderate antibacterial properties.     

A stochastic programming approach to determine robust delivery profiles in area forwarding inbound logistics networks

One technique to coordinate the suppliers’ and the producers’ production plans in a supply chain is the use of delivery profiles, which provide fixed delivery frequencies for all suppliers. The selection of a delivery profile assignment has major effects on the cost efficiency and the robustness of a supply chain and thus should be performed carefully. In this work, we consider planning approaches to select delivery profiles for the case of area forwarding-based inbound logistics networks, which are commonly used in several industries to consolidate supplies in an early stage of transport. We present a two-stage stochastic mixed integer linear programming model to determine robust delivery profile assignments under uncertain and infrequent demands and complex tariff systems. The model is embedded into a solution framework consisting of scenario generation and reduction techniques, a decomposition approach, a genetic algorithm, and a standard MILP solver. On the basis of an industrial case study, we show that our approach is computationally feasible and that the planning solutions obtained by our model outperform both a deterministic approach and the planning methodology prevailing in industrial practice.     

Written arguments and collaborative speech acts in practising the argumentative power of language through chat debates

This study deals with the quality of argumentation and collaboration in students’ chat debates. The argumentative interaction between students is analysed by categorising their speech turns into seven functional categories. The argumentative task-related parts of the students’ discussions are further analysed into collaborative and non-collaborative speech acts. Argumentation patterns are revealed when the results of both analyses are combined with observations on the students’ writing styles. Students (n = 24) participated in 12 dyadic debates concerning either nuclear power (NP) or genetically modified organisms (GMO). We found that the majority (67.2%) of the speech turns in NP debates and almost half (47.8%) of the speech turns in GMO debates belong to the argumentative categories (explore and deepen; arguments; opinions). Furthermore, there are four types of debates that could be placed in the continuum of sophisticated argumentative debates (written code of language was used)—oral-like debates (the quality of argumentation was quite low). Irrespective of the level of argumentation, all the debates were collaborative. The study shows that students acquired the skill to use language collaboratively. Most students embedded short collaborative semi-oral utterances in their written arguments to provoke and scaffold the debate.     

In vitro transactivation potencies of black-footed albatross (Phoebastria nigripes) AHR1 and AHR2 by dioxins to predict CYP1A expression in the wild population

Our previous studies have detected high levels of dioxins and related compounds (DRCs) including polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs), and coplanar PCBs (Co-PCBs) in the black-footed albatross (BFA), Phoebastria nigripes, from the North Pacific region. We have also cloned two aryl hydrocarbon receptors, AHR1 and AHR2, of the BFA. To evaluate the sensitivity to DRCs in the BFA and to assess the status of cytochrome P450 1A (CYP1A) induction in the wild population, this study investigated the mRNA expression levels of BFA AHR1 and AHR2 and also the transactivation potencies of each AHR by 15 selected DRC congeners. Quantitative real-time PCR of BFA AHR mRNAs showed that hepatic AHR1 is more highly expressed than AHR2. Transactivation by graded concentrations of individual DRCs was measured in COS-7 cells, where BFA AHR1 or AHR2 was transiently transfected. For congeners that exhibited AHR-mediated dose-dependent activities, 50% effective concentration (EC(50)) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) relative potencies (REPs) were estimated. Based on the estimates of the REPs, TCDD induction equivalency factors (IEFs) were determined. For BFA AHR1, PeCDF was equipotent to TCDD, but other congeners exhibited lower IEFs. For BFA AHR2, PCDD/F congeners except OCDD/F showed IEFs ≥ 1.0. Using BFA AHR1- or AHR2-IEFs and hepatic concentrations of DRCs in North Pacific BFAs, TCDD induction equivalents (IEQs) were calculated. We further constructed nonlinear regression models on the relationships between BFA AHR1- or AHR2-IEF derived total IEQ or WHO-TEF derived total TEQ and ethoxyresorufin-O-deethylase activity (EROD) in the liver of wild BFAs. The results indicated that the relationships of BFA AHR1- and AHR2-based IEQs and EROD were predictable from BFA AHR1- and AHR2-mediated transactivation by TCDD, respectively. Collectively, these results suggest that the in vitro assay incorporating the AHR of species of concern would be a useful tool to predict the sensitivity to DRCs in the species and CYP1A induction in the wild population.     

Reference biomaterials for biological evaluation

The variability associated with most of the biological evaluation studies is relatively large and hence experimental controls are frequently employed to ensure that the results are reliable. These experimental controls, either positive or negative controls, could be considered as reference materials in the context of biological evaluation. Currently, reference biomaterial needs across the world are not addressed satisfactorily. Affordability and lack of availability of certified reference materials necessitates the development and the use of laboratory developed RMs. A well defined characterization strategy is essential for the successful development of in house reference materials. This article provides an overview of the current international status in the area of reference biomaterials and enumerates the steps involved in the development of an in house reference material. The production and characterization of commercially pure titanium pins for use as negative controls during muscle implantation studies is presented as a case study.     

Study on Reuse of Coconut Fiber Chemical Retting Bath. Part II---Recovery and Characterization of Lignin

Study aimed at recovery of lignin from the reused residual liquor of chemical retting bath of coconut fiber caused by partial delignification to make it soft. The lignin of 8.9% was obtained after recovery (maintaining pH 2.0 for 1 h at ambient temperature) and further purification. Extracted lignin is characterized through FTIR, TGA and particle size analysis. FTIR showed absence of polysaccharides in purified lignin. TGA indicates presence of higher methyl-aryl ether groups than aromatic groups in lignin of coconut fibre. Analysis reveals about 91% of particles in the rage of 1–500 µm, which shows its good dispersiblity in fluid. Recovery of lignin associated with two benefits i.e., diversified use of extracted pure lignin and reduction of organic load of the waste liquor to make it suitable for discharge.     

Mathematical models and solution methods for optimal container terminal yard layouts

In this paper, we introduce an integer linear program for planning the layout of container yards. We concentrate on a special layout class of container yards which we call yard layout with transfer lanes. For those layouts typically rubber tired gantry cranes are used for stacking operations and trucks for horizontal transports. We show that the optimization model can be formulated as a special type of a resource constrained shortest path problem for which the LP relaxation always has at least one integer optimal solution. This model is restricted to a rectangular storage yard which allows a linear formulation. For an arbitrary shaped container yard we adopt the model and develop a variable neighborhood descent (VND) heuristic for solving non-rectangular instances. Concerning the rectangular case, we show that the VND heuristic achieves optimal solutions for 38% of the realistic test instances.