Optimisation of bulk carrier loading and discharge

This report summarises progress made towards the problem submitted by Rusal Aughinish at the 93rd European Study Group with Industry. Rusal Aughinish is a company that refines alumina from bauxite. The problem presented to the study group was to review the percentage of time that the company’s inner berth was occupied and how to minimise this percent- age. A number of different approaches were taken with this aim in mind. Firstly, data supplied by Rusal Aughinish was analysed. This analysis found that there is an optimal loading rate (with respect to eliminating demurrage costs) and suggested bands of optimal ship sizes. Further to these studies, two models of Rusal Aughinish’s shipping process were developed by the group: a simulation model and an analytical model. Both models were found to replicate the shipping process reasonably well and were, hence, used to study alumina output, berth occupancy and demurrage costs

THE COMPLEX ORGANIZATION OF EUKARYOTIC CELL NUCLEUS (III): THE NUCLEAR MATRIX AND THE NUCLEAR LAMINA

A large variety of nuclear fibrous proteins (such as actin, myosin, lamin B, transcription factors, topoisomerases, etc) represent constitutive elements of complex structures present in the eukaryotic nuclei: the nuclear matrix and the nuclear lamina, repectively. These nuclear compartments, with fibrous network-like structure, play crucialroles in structural organization of nuclei, chromatin remodeling, DNA transcription, signals transduction, cell cycle regulation, embryonic development and other nuclear basic processes.</p

Linear quadratic regulation control for falling liquid films

We propose and analyse a new methodology based on linear-quadratic regulation (LQR) for stabilising falling liquid films via blowing and suction at the base. LQR methods enable rapidly responding feedback control by precomputing a gain matrix, but are only suitable for systems of linear ordinary differential equations (ODEs). By contrast, the Navier-Stokes equations that describe the dynamics of a thin liquid film flowing down an inclined plane are too complex to stabilise with standard control-theoretical techniques. To bridge this gap we use reduced-order models – the Benney equation and a weighted-residual integral boundary layer model – obtained via asymptotic analysis to derive a multi-level control framework. This framework consists of an LQR feedback control designed for a linearised and discretised system of ODEs approximating the reduced-order system, which is then applied to the full Navier-Stokes system. The control scheme is tested via direct numerical simulation (DNS), and compared to analytical predictions of linear stability thresholds and minimum required actuator numbers. Comparing the strategy between the two reduced-order models we show that in both cases we can successfully stabilise towards a uniform flat film across their respective ranges of valid parameters, with the more accurate weighted-residual model outperforming the Benney-derived controls. The weighted-residual controls are also found to work successfully far beyond their anticipated range of applicability. The proposed methodology increases the feasibility of transferring robust control techniques towards real-world systems, and is also generalisable to other forms of actuation

Weak Charge Transfer between an Acceptor Molecule and Metal Surfaces Enabling Organic/Metal Energy Level Tuning

Evidence for charge transfer (CT) between the electron acceptor molecule octafluoroanthraquinone (FAQ) and the metal surfaces Ag(111) and polycrystalline Au is provided by ultraviolet photoelectron spectroscopy. The energy level alignment of subsequently deposited sexithienyl (6T) on FAQ-precovered metal substrates was investigated. Due to the metal work function change induced by the FAQ-metal CT, the hole injection barrier of 6T on FAQ-precovered metals could be reduced by up to 0.60 eV compared to that of 6T on pristine metal surfaces

Chemoselective oxidation of 2-thiomethyl-4,6-dimethyl-pyrimidine on nanostructured tantalum oxides

A series of tantala-silica catalysts (15 wt.% Ta2O5) were prepared by sol-gel from tantalum and silica ethoxides. These syntheses were carried out using two families of quaternary ammonium salts, CnH2n+1(CH3)(3)NBr (n = 14, 16, 18) and (CnH2n+1)(4)NBr (n = 10, 12, 16, 18) were used as surfactants. The catalysts were characterized by adsorption-desorption isotherms of N-2 at 77 K, XRD, SAXS, DRUV-Vis, py and CDCl3-FTIR, and XPS. The catalytic tests were carried out in dioxane, methanol or CHCl3, and indicated that both conversion and selectivity depend on the size of tantalum nanoxide. Leaching investigation showed that part of Ta is extracted from the network, but it segregates on the support as Ta2O5. (C) 2004 Elsevier B.V. All rights reserved

Investigating SARS-CoV-2 surface and air contamination in an acute healthcare setting during the peak of the COVID-19 pandemic in London

BACKGROUND: Evaluation of SARS-CoV-2 surface and air contamination during the COVID-19 pandemic in London. METHODS: We performed this prospective cross-sectional observational study in a multi-site London hospital. Air and surface samples were collected from seven clinical areas, occupied by patients with COVID-19, and a public area of the hospital. Three or four 1.0 m3 air samples were collected in each area using an active air sampler. Surface samples were collected by swabbing items in the immediate vicinity of each air sample. SARS-CoV-2 was detected by RT-qPCR and viral culture; the limit of detection for culturing SARS-CoV-2 from surfaces was determined. RESULTS: Viral RNA was detected on 114/218 (52.3%) of surfaces and 14/31 (38.7%) air samples but no virus was cultured. The proportion of surface samples contaminated with viral RNA varied by item sampled and by clinical area. Viral RNA was detected on surfaces and in air in public areas of the hospital but was more likely to be found in areas immediately occupied by COVID-19 patients than in other areas (67/105 (63.8%) vs. 29/64 (45.3%) (odds ratio 0.5, 95% confidence interval 0.2-0.9, p=0.025, Chi squared test)). The high PCR Ct value for all samples (>30) indicated that the virus would not be culturable. CONCLUSIONS: Our findings of extensive viral RNA contamination of surfaces and air across a range of acute healthcare settings in the absence of cultured virus underlines the potential risk from environmental contamination in managing COVID-19, and the need for effective use of PPE, physical distancing, and hand/surface hygiene

Exploring the role of information systems in mitigating gate congestion using simulation: theory and practice at a bulk export terminal gate

Using an Australian wood chip export terminal as a case study, this research presents a terminal gate simulation model that improves understanding of the complex interactions at the terminal gate and describes the potential of information and digital systems alternatives for mitigating congestion. The alternatives modelled include: a terminal appointment system to schedule truck arrivals; integrating weigh-bridge information to eliminate one stage of the unloading process; and, reducing conveyor operation time.Simulation results indicate that a terminal appointment system can reduce turnaround times by up to 23%, primarily through a reduction in waiting times. Integrating weigh-bridge information can improve turnaround by up to 18%, while reducing the conveyor operation time can improve turnaround by up to 5%. The paper highlights that achieving these simulated results in practice actually relies on a range of factors and assumptions hard to embed in the simulation. These factors influence the nature of the complex interactions at the terminal gate and include the extent to which stakeholders are willing to share information and develop or retain levels of trust between each other.The paper argues that one potentially effective strategy for aligning stakeholders’ interests involves engaging them all in the decision-making processes in finding and developing a suitable congestion management solution. This approach mitigates concerns regarding system abuse, ensures all technological and business requirements of stakeholders are considered and, enhances the implementation process to deliver increased effectiveness of the solution.This research is part of a major ongoing research project undertaken in Australia funded by the Australian Research Council through the Industrial Transformation Research Program