Intercalation of Hydrotalcites with Hexacyanoferrate(II) and (III)-a ThermoRaman Spectroscopic Study

Raman spectroscopy using a hot stage indicates that the intercalation of hexacyanoferrate(II) and (III) in the interlayer space of a Mg,Al hydrotalcites leads to layered solids where the intercalated species is both hexacyanoferrate(II) and (III). Raman spectroscopy shows that depending on the oxidation state of the initial hexacyanoferrate partial oxidation and reduction takes place upon intercalation. For the hexacyanoferrate(III) some partial reduction occurs during synthesis. The symmetry of the hexacyanoferrate decreases from Oh existing for the free anions to D3d in the hexacyanoferrate interlayered hydrotalcite complexes. Hot stage Raman spectroscopy reveals the oxidation of the hexacyanoferrate(II) to hexacyanoferrate(III) in the hydrotalcite interlayer with the removal of the cyanide anions above 250 °C. Thermal treatment causes the loss of CN ions through the observation of a band at 2080 cm-1. The hexacyanoferrate (III) interlayered Mg,Al hydrotalcites decomposes above 150 °C

Senior Recital, Gabriel Taylor, guitar

The presentation of this senior recital will fulfill in part the requirements for the Bachelor of Music degree in Performance. Gabriel Taylor studies guitar with David Toussaint

Early diagenetic vivianite [Fe-3(PO4)(2) center dot 8H(2)O] in a contaminated freshwater sediment and insights into zinc uptake: a mu-EXAFS, mu-XANES and Raman study

The sediments in the Salford Quays, a heavily-modified urban water body, contain high levels of organic matter, Fe, Zn and nutrients as a result of past contaminant inputs. Vivianite [Fe3(PO4)2 · 8H2O] has been observed to have precipitated within these sediments during early diagenesis as a result of the release of Fe and P to porewaters. These mineral grains are small (<100 μm) and micron-scale analysis techniques (SEM, electron microprobe, μ-EXAFS, μ-XANES and Raman) have been applied in this study to obtain information upon the structure of this vivianite and the nature of Zn uptake in the mineral. Petrographic observations, and elemental, X-ray diffraction and Raman spectroscopic analysis confirms the presence of vivianite. EXAFS model fitting of the FeK-edge spectra for individual vivianite grains produces Fe–O and Fe–P co-ordination numbers and bond lengths consistent with previous structural studies of vivianite (4O atoms at 1.99–2.05 Å; 2P atoms at 3.17–3.25 Å). One analysed grain displays evidence of a significant Fe3+ component, which is interpreted to have resulted from oxidation during sample handling and/or analysis. EXAFS modelling of the Zn K-edge data, together with linear combination XANES fitting of model compounds, indicates that Zn may be incorporated into the crystal structure of vivianite (4O atoms at 1.97 Å; 2P atoms at 3.17 Å). Low levels of Zn sulphate or Zn-sorbed goethite are also indicated from linear combination XANES fitting and to a limited extent, the EXAFS fitting, the origin of which may either be an oxidation artifact or the inclusion of Zn sulphate into the vivianite grains during precipitation. This study confirms that early diagenetic vivianite may act as a sink for Zn, and potentially other contaminants (e.g. As) during its formation and, therefore, forms an important component of metal cycling in contaminated sediments and waters. Furthermore, for the case of Zn, the EXAFS fits for Zn phosphate suggest this uptake is structural and not via surface adsorption

Investigation of Optimal Control Allocation for Gust Load Alleviation in Flight Control

Advances in sensors and avionics computation power suggest real-time structural load measurements could be used in flight control systems for improved safety and performance. A conventional transport flight control system determines the moments necessary to meet the pilot's command, while rejecting disturbances and maintaining stability of the aircraft. Control allocation is the problem of converting these desired moments into control effector commands. In this paper, a framework is proposed to incorporate real-time structural load feedback and structural load constraints in the control allocator. Constrained optimal control allocation can be used to achieve desired moments without exceeding specified limits on monitored load points. Minimization of structural loads by the control allocator is used to alleviate gust loads. The framework to incorporate structural loads in the flight control system and an optimal control allocation algorithm will be described and then demonstrated on a nonlinear simulation of a generic transport aircraft with flight dynamics and static structural loads

Effectiveness of cognitive-behaviour therapy for hoarding disorder in people with mild intellectual disabilities

Evaluations of cognitive behavioural interventions for hoarding for those with intellectual disabilities (ID) have not been previously attempted. This investigation therefore examined the acceptability and effectiveness of cognitive-behavioural therapy (CBT) in a sample of N = 14 adults with mild ID. All participants had hoarding as their primary problem and received twelve individual CBT sessions, all conducted via domiciliary visits. The primary outcome measure was an environmental measure (Clutter Image Rating Scale), which was scored at baseline, end of treatment and at six-month follow-up. Acceptability of CBT was measured via the treatment refusal and dropout rate. Secondary self-report outcomes included measures of hoarding, depression and anxiety. Results demonstrate that hoarding significantly reduced following treatment on both self-report and environmental assessment. No participants refused or dropped out of treatment and that there was no evidence of relapse over the follow-up period. No adverse treatment incidences were reported. This open trial suggests that CBT may be a safe and effective intervention for hoarding difficulties in people with ID, but that the evidence base in this population needs urgent and detailed attention

A Framework for Optimal Control Allocation with Structural Load Constraints

Conventional aircraft generally employ mixing algorithms or lookup tables to determine control surface deflections needed to achieve moments commanded by the flight control system. Control allocation is the problem of converting desired moments into control effector commands. Next generation aircraft may have many multipurpose, redundant control surfaces, adding considerable complexity to the control allocation problem. These issues can be addressed with optimal control allocation. Most optimal control allocation algorithms have control surface position and rate constraints. However, these constraints are insufficient to ensure that the aircraft's structural load limits will not be exceeded by commanded surface deflections. In this paper, a framework is proposed to enable a flight control system with optimal control allocation to incorporate real-time structural load feedback and structural load constraints. A proof of concept simulation that demonstrates the framework in a simulation of a generic transport aircraft is presented

Gradient elasticity: a transformative stress analysis tool to design notched components against uniaxial/multiaxial high-cycle fatigue

This paper investigates the accuracy of gradient elasticity in estimating high-cycle fatigue strength of notched components subjected to both uniaxial and multiaxial fatigue loading. A novel design methodology is formulated by combining Ru and Aifantis’ gradient elasticity with the Theory of Critical Distances and the Modified Wöhler Curve Method. The keyfeature of this innovative design methodology is that, via the Theory of Critical Distances, gradient elasticity’s length scale parameter is directly estimated from conventional material fatigue properties (i.e., the plain fatigue limit and the threshold value of the stress intensity factor). From a stress analysis point of view, the proposed approach directly post-processes the gradient-enriched stress states determined, at the hot-spots, on the surface of the component under investigation (and independently of the sharpness of the stress concentrator being assessed). The accuracy and reliability of this design method was checked by using a large number of experimental results taken from the literature and generated by testing notched metallic samples under uniaxial as well as under multiaxial fatigue loading. This comprehensive validation exercise demonstrates that the systematic usage of this transformative design approach leads to the same level of accuracy as the one which is obtained by applying the classic Theory of Critical Distances. This result is certainly remarkable since the proposed approach is not only very efficient from a computational point of view, but it also allows high-cycle fatigue damage to be assessed by directly postprocessing gradient-enriched stress states determined on the surface of the component being assessed

The Freshman, vol. 5, no. 8

The Freshman was a weekly, student newsletter issued on Mondays throughout the academic year. The newsletter included calendar notices, coverage of campus social events, lectures, and athletic teams. The intent of the publication was to create unity, a sense of community, and class spirit among first year students