No / Two new complexes, [Fe3(μ3-O)(inicH)6(H2O)3][Gd(NO3)6]·(NO3)4·nH2O (1) and [Fe3(μ3-O)(inicH)6(H2O)3][Dy(NO3)5 (H2O)]·(NO3)5·n(H2O) (2) with two isolated complex moieties, were generated when isonicotinic acid was treated with iron(III) nitrate and the corresponding lanthanide(III) nitrate in water. The structures were determined by single-crystal X-ray diffraction studies. In these compounds, the anionic lanthanide complexes are encapsulated by trinuclear [Fe3(μ3-O)(inicH)6(H2O)3]7+ cationic cluster units, which is facilitated by hydrogen-bonding interactions. Investigation of the magnetic properties reveals that 2 shows slow relaxation of magnetization at low magnetic field (Hdc = 1.0 kOe), with an energy barrier of 23 K originating from a single [Dy(NO3)5(H2O)]2– anion. / Errata: 2014(25): 4228 (http://onlinelibrary.wiley.com/enhanced/doi/10.1002/ejic.201402684)

No / Half-sandwich complexes of precious metals are a versatile class of organometallic compounds. Their accessibility, robustness, and air-stability are examples of the unique properties that allow their applications in various fields of chemistry (e.g. catalysis), and as anticancer drug candidates. Half-sandwich complexes generally follow the 18-electron rule, although some stable 16-electron (16-e) complexes have been isolated. The latter are generally coordinatively unsaturated leading to potential applications in catalysis and as precursors for 18-electron (18-e) complexes. Six 16-e complexes [Ru(η6-p-cymene)(1,2-benzene-1,2-dithiolato)] (1), [Os(η6-p-cymene) (1,2-benzene-1,2-dithiolato)] (2), [Ir(η5-pentamethylcyclopentadiene) (1,2-benzene-1,2-dithiolato)] (3), [Ru(η6-p-cymene)(1,2-dicarba-closo- dodecaborane-1,2-dithiolato)] (4), [Os(η6-p-cymene)(1,2-dicarba-closo- dodecaborane-1,2-dithiolato)] (5), and [Ir(η5-pentamethylcyclopentadiene)(1,2-dicarba-closo-dodecaborane-1,2-dithiolato)] (6) were synthesised by reactions between 1,2-benzenedithiol (1, 2, 3) or 1,2-dicarba-closo-dodecaborane-1,2-dithiol (4, 5, 6) and the corresponding metal dimers. In solution (10-4 M) at ambient temperature, the six complexes are stable electron-deficient 16-electron monomers, although the formation of a more electronically stable 18-electron dimer is observed for complex 1 at millimolar concentrations. The six complexes exhibit dramatic differences in reactivity towards electron-donor molecule. The in-vitro anti-inflammatory activities of the 16-e complexes 1 – 6 were investigated on MRC 5-fibroblast and lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Cells were exposed for 24h to the 16-e complexes 1 – 6 in the concentrations range of 10, 20, 50 and 100uM. After this, drugs were removed and nitric oxide (NO) concentration in the cultured medium was determined by the Griess reaction. Cells were then washed and placed in fresh growth medium for a further 24h as a recovery period. Cell viability was then assessed by MTT assay. Our preliminary data showed that complex 1 – 6 showed some anti-inflammatory effect on both lines, but with slightly differences between them, suggesting that the M-S2C2 scaffold of the electron-deficient complexes is the main structural moiety responsible for such effect. Further studies will focus on the matching these effects with their structures. / Abstract of conference paper.

No / This article corrects http://onlinelibrary.wiley.com/enhanced/doi/10.1002/ejic.201402114. 2014(19): 3065-3071.

No / Background Anecdotally, it has long been felt by academic staff that students on the Bradford 5-year sandwich degree programme (intercalated pre-registration training) performed differently on return to university from those on the continuous 4-year programme. Direct comparisons between cohorts have been difficult to undertake as the two groups were taught separately in their final stage. In 2016-17, a cohort of returning sandwich students was taught alongside a comparable group of continuous students in a final stage module. This study compares the results from these two student cohorts. Method The Pharmacy Special Studies module offered a very broad range of opportunities across laboratory research, systematic and scoping review, product development and care-orientated topics including audit, and analysis of clinical cases, organised in 9 separate “strands.” Students from the sandwich (n=99) and continuous (n=89) courses were offered the same selection of learning experiences. Assessment was by oral presentation and discussion (slides or poster) and written report. The Level 7 marking schemes used were designed so that the highest marks were only available to reward student demonstration of the higher-level critical, analytical and interpretative skills. Results Student performance across all 9 strands of the module was comparable. When module results were split according to cohort, a strong divergence was observed. Sandwich student results displayed an approximately bell-shaped distribution with a mean mark 73.2% (SD 8.1). In contrast, the continuous student results had a lower mean 67.3% (SD 8.5, p<10-5); moreover, the distribution of these marks was distorted with a ‘cliff edge’ in the low 70s and a long tail. Conclusion This analysis shows that students who had completed 6 months pre-registration training achieved, on average, higher grades. Moreover, they demonstrated improved higher-level skills of interpretation and critical analysis compared with the continuous group. Although this is a one-year “snapshot” observation it appears to show that following 6 months preregistration training, students are better able to critically evaluate and interpret data and draw evidence-based conclusions. Such a result could provide evidence for the benefits of intercalated placements and indicate the optimal location of professional training within the academic course. Any impact on pre-registration training itself remains to be determined. / Abstract, presented at the Pharmacy Education Conference 2017, Manchester, United Kingdom.

Yes / Ruthenium compounds have been shown to be promising alternatives to platinum(II) drugs. However, their clinical success depends on achieving mechanisms of action that overcome Pt-resistance mechanisms. Electron-deficient organoruthenium complexes are an understudied class of compounds that exhibit unusual reactivity in solution and might offer novel anticancer mechanisms of action. Here, we evaluate the in vitro and in vivo anticancer properties of the electron-deficient organoruthenium complex [(p-cymene)Ru(maleonitriledithiolate)]. This compound is found to be highly cytotoxic: 5 to 60 times more potent than cisplatin towards ovarian (A2780 and A2780cisR), colon (HCT116 p53+/+ and HCT116 p53−/−), and non-small cell lung H460 cancer cell lines. It shows no cross-resistance and is equally cytotoxic to both A2780 and A2780cisR cell lines. Furthermore, unlike cisplatin, the remarkable in vitro antiproliferative activity of this compound appears to be p53-independent. In vivo evaluation in the hollow-fibre assay across a panel of cancer cell types and subcutaneous H460 non-small cell lung cancer xenograft model hints at the activity of the complex. Although the impressive in vitro data are not fully corroborated by the in vivo follow-up, this work is the first preclinical study of electron-deficient half-sandwich complexes and highlights their promise as anticancer drug candidates. / UF150295/Royal Society; University of Bradford; Government Department of Business, Energy and Industrial Strategy; SBF003\1170/British Heart Foundation Springboard Award; AMS_/Academy of Medical Sciences/United Kingdom

Yes / Electron‐deficient half‐sandwich complexes are a class of under‐studied organometallics with demonstrated potential as metallodrug candidates. The present study investigates the effect of two 16‐electron organoruthenium complexes ([( p‐ cym)Ru(benzene‐1,2‐dithiolato)] ( 1 ) and [( p ‐cym)Ru(maleonitriledithiolate)] ( 2 )) on the cell viability of non‐immortalised human lymphocytes from healthy individuals. The genotoxic effects of 1 and 2 in lymphocytes using the Comet and cytokinesis‐block micronucleus assays is also investigated. Gene expression studies were carried out on a panel of genes involved in apoptosis and DNA damage repair response. Results show that the two 16‐electron complexes do not have significant effect on the cell viability of human lymphocytes from healthy individuals. However, an increase in DNA damage is induced by both compounds, presumably through oxidative stress production. / This project was supported by the Royal Society (University Research Fellowship No. UF150295 to NPEB), the University of Bradford (RDF Award), and by the Academy of Medical Sciences/the Wellcome Trust/ the Government Department of Business, Energy and Industrial Strategy/ the British Heart Foundation Springboard Award [SBF003\1170 to NPEB].

Vacuum assisted resin transfer molding (VARTM) is a low cost resin infusion process being developed for the manufacture of composite structures. VARTM is being evaluated for the manufacture of primary aircraft structures, including foam sandwich composite materials. One of the benefits of VARTM is the ability to resin infiltrate large or complex shaped components. However, trial and error process development of these types of composite structures can prove costly and ineffective. Therefore, process modeling of the associated flow details and infiltration times can aide in manufacturing design and optimization. The purpose of this research was to develop a process using VARTM to resin infiltrate stitched and unstitched dry carbon fiber preforms with polymethacrylimide foam cores to produce composite sandwich structures. The infiltration process was then used to experimentally verify a three-dimensional finite element model for VARTM injection of stitched sandwich structures. Using the processes developed for the resin infiltration of stitched foam core preforms, visualization experiments were performed to verify the finite element model. The flow front progression as a function of time and the total infiltration time were recorded and compared with model predictions. Four preform configurations were examined in which foam thickness and stitch row spacing were varied. For the preform with 12.7 mm thick foam core and 12.7 mm stitch row spacing, model prediction and experimental data agreed within 5%. The 12.7 mm thick foam core preform with 6.35 mm row spacing experimental and model predicted data agreed within 8%. However, for the 12.7 mm thick foam core preform with 25.4 mm row spacing, the model overpredicted infiltration times by more 20%. The final case was the 25.4 mm thick foam core preform with 12.7 mm row spacing. In this case, the model overpredicted infiltration times by more than 50%. This indicates that the model did not accurately describe flow through the needle perforations in the foam core and could be addressed by changing the mesh elements connecting the two face sheets. / Master of Science

Optimization is a decision making process to solve problems in a number of fields including engineering mechanics. Bio-inspired optimization algorithms, including genetic algorithm (GA), have been studied for many years. There is a large literature on applying the GA to mechanics problems. However, disadvantages of the GA include the high computational cost and the inability to get the global optimal solution that can be found by using a honeybee-inspired optimization algorithm, called the New Nest-Site Selection (NeSS). We use the NeSS to find optimal parameters for three mechanics problems by following the three processes: screening, identifying relationships, and optimization. The screening process identifies significant parameters from a set of input parameters of interest. Then, relationships between the significant input parameters and responses are established. Finally, the optimization process searches for an optimal solution to achieve objectives of a problem. For the first two problems, we use the NeSS algorithm in conjunction with a third order shear and normal deformable plate theory (TSNDT), the finite element method (FEM), a one-step stress recovery scheme (SRS) and the Tsai-Wu failure criterion to find the stacking sequence of composite laminates and the topology and materials for doubly curved sandwich shells to maximize the first failure load. It is followed by the progressive failure analysis to determine the ultimate failure load. For the sandwich shell, we use the maximum transverse shear stress criterion for delineating failure of the core, and also study simultaneously maximizing the first failure load and minimizing the mass subject to certain constraints. For composite laminates, it is found that the first failure load for an optimally designed stacking sequence exceeds that for the typical [0°/90°]₅ laminate by about 36%. Moreover, the design for the optimal first failure load need not have the maximum ultimate load. For clamped laminates and sandwich shells, the ultimate load is about 50% higher than the first failure load. However, for simply supported edges the ultimate load is generally only about 10% higher than the first failure load. For the atmospheric spray process, we employ the NeSS algorithm to find optimal values of four process input parameters, namely the argon flow rate, the hydrogen flow rate, the powder feed rate and the current, that result in the desired mean particle temperature and the mean particle velocity when they reach the substrate. These optimal values give the desired mean particle temperature and the mean particle velocity within 5% of their target values. / Ph. D. / An optimization process iteratively searches for the best solution from all feasible solutions in the search space that satisfy prespecified criteria. Optimization problems consist of sets of parameters, constraints, and objective functions. Here we use a honeybee-inspired optimization algorithm, called the New Nest-Site Selection (NeSS), to find optimal parameters for three mechanics problems. In the first problem, we optimize the design of an assembly of layers of unidirectional fiber-reinforced materials called composite laminates. Because of their high specific strength and directional-dependent stiffness as compared to those of metals, the composite laminates are being increasingly used in aerospace and automotive industries. After having analyzed deformations of a composite laminate, a failure criterion is used to determine if any point in the structure has failed. The minimum load for which the failure criterion is satisfied at a point is called the first ply failure load. Here we determine the fiber orientation angle in each layer of a rectangular laminate deformed statically by transverse loads applied on the top surface that maximizes the first ply failure load. Subsequently, the load is incrementally increased for the optimally designed laminate and the strength of the failed elements is degraded till the structure cannot support any additional load. The maximum load a structure can support is called the ultimate load. It is found that for a laminate with all edges clamped, the ultimate load can be 40% more than the first ply failure load. We extend the above work to design an optimal geometry and an optimal combination of materials of the facesheets and the core that simultaneously maximizes the first failure load, minimizes the weight of a doubly curved sandwich shell, and satisfies pre-specified constraints. The doubly curved sandwich structure of interest here is comprised of two thin parallel unidirectional fiber-reinforced facesheets bonded to and enclosing a relatively thick mid-layer made of a material softer and lighter than that of the facesheets. The sandwich structures are widely used in aircraft, marine, automobile, and civilian infrastructures. It is found that optimal designs for doubly curved sandwich shells strongly depend upon how the shell edges are supported, and shells designed for the maximum first failure load need not have the maximum ultimate load. An atmospheric plasma spray process (APSP) has been successfully used to coat components for gas turbines, airframe, engines and drive trains, and silicon chips. In the APSP, coating powder is injected into the plasma, which is a mixture of ionized gases such as argon, hydrogen, and helium, through a powder port generally oriented perpendicular to the plasma jet axis. Through interactions with the plasma jet, the particles are accelerated, heated and partially melted before they strike the substrate and are deposited on it to form a coating. It is believed that the coating properties and its quality depend on the particles’ temperature and velocity when they hit the substrate. Here we determine optimum values of four input parameters, namely, the argon flow rate, the hydrogen flow rate, the current, and the powder feed rate to achieve the desirable mean particles’ temperature and the mean particles’ velocity. It is found that the four processes input parameters can be optimized to attain particles’ characteristics within 5% of their prespecified desired values.

Accurately modeling damping in engineering structures has plagued scientist and engineers for decades. The integration of viscoelastic materials into engineering structures can reduce undesired vibrations and serve as an effective passive control mechanism. Various techniques have been developed to model viscoelastic materials. The growing popularity of finite element analysis in the 1980s and 1990s spawned new techniques for modeling damping in complex structures. The technique defined in this dissertation can be incorporated into finite element models. In metals, the modulus of elasticity can be modeled as a constant. That is, the modulus of elasticity is not treated as a function of frequency in dynamic models. For viscoelastic materials, the modulus of elasticity can be assumed to be constant for static forces and sinusoidal forcing functions. However, when viscoelastic materials undergo excitations from a random or transient forcing function the constant modulus of elasticity assumption may not be valid. This is because the second order equation of motion has non-constant coefficients or coefficients that vary as a function of frequency. The Golla-Hughes-McTavish (GHM) method is a technique used to incorporate the frequency dependency of viscoelastic materials into finite element models. The GHM method is used as a way to alleviate working with second order differential equations with non-constant coefficients. This dissertation presents the theory for a new material modulus function suitable for application within the framework of the GHM method. However, the new material modulus function uses different assumptions and is referred to as the Modified GHM method or MGHM method. The MGHM method is shown to improve the curve fit and damping characteristics of the GHM method. Additionally, the MGHM method is shown to reduce to the GHM method when the original GHM assumptions are imposed. / Ph. D.

Tableau d'honneur de la Faculté des études supérieures et postdorales, 2015-2016 / Le but de ce travail est de produire et de caractériser des structures sandwich à trois couches asymétriques avec ou sans cœur moussé. Pour ce faire, le travail est divisé en deux sections. Dans la première partie, l'effet de la variation des quantités d'agent de couplage et de fibres sont étudiés. La microscopie et la caractérisation mécanique sont utilisées pour évaluer l'effet du polyéthylène greffé d’anhydride maléique (MAPE) sur l'amélioration de la compatibilité entre les fibres de chanvre et le polyéthylène de haute densité (HDPE). Les résultats montrent que les propriétés mécaniques optimales (tension, flexion, torsion et impact) sont obtenues à 9% en poids de MAPE. Dans la deuxième partie, des structures sandwich asymétriques à trois couches, avec ou sans cœur moussé, sont produites par extrusion suivi par un moulage en compression. Les effets de paramètres tels que la densité du cœur, la concentration en chanvre dans les peaux, les épaisseurs des couches et la séquence d'empilage sur leurs comportements en flexion et en impact sont étudiés. Les effets combinés de tous les paramètres mènent à contrôler les propriétés mécaniques (traction, torsion, flexion et impact) des structures sandwich asymétriques. / The aim of this work is to produce and characterize asymmetric three-layer sandwich structures with and without foam core. In order to do so, the work is divided in two sections. In the first part, the effect of coupling agent and fiber content is investigated. Micrographs and mechanical characterizations are used to show that the addition of maleic anhydride polyethylene (MAPE) improved the compatibility between hemp and high density polyethylene (HDPE). It is found that the optimum mechanical properties (tension, flexion, torsion and impact) are obtained with 9% wt. of MAPE in the composite. In the second part, asymmetric three-layer sandwich structures with and without foam core were produced using extrusion followed by compression molding. The effect of different parameters such as core density, skin hemp content, layer thickness, and stacking sequence on their flexural and impact behaviors are studied. The combined effect of all the parameters was found to control the mechanical properties (tension, torsion, flexion and impact) of asymmetric sandwich structures.