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Yes / Derivatives of fulgides have been shown to have interesting photochromic properties. We have synthesised a number of such derivatives and have found, in some cases, that crystals can be made to change colour on crushing, a phenomenon we have termed "tribochromism". We have studied a number of derivatives by X-ray crystallography, to see if the colour is linked to molecular structure or crystal packing, or both, and our structural results have been supported by calculation of molecular and lattice energies. A number of 5-dicyanomethylene-4-diphenylmethylene-3-disubstitutedmethylene-tetrahydrofuran-2 -one compounds have been prepared and structurally characterised. The compounds are obtained as yellow or dark red crystals, or, in one case, both. In two cases where yellow crystals were obtained, we found that crushing the crystals gave a deep red powder. Structure determinations, including those of the one compound which gave both coloured forms, depending on crystallisation conditions, showed that the yellow crystals contained molecules in which the structure comprised a folded conformation at the diphenylmethylene site, whilst the red crystals contained molecules in a twisted conformation at this site. Lattice energy and molecular conformation energies were calculated for all molecules, and showed that the conformational energy of the molecule in structure IIIa (yellow) is marginally higher, and the conformation thus less stable, than that of the molecule in structure IIIb (red). However, the van der Waals energy for crystal structure IIIa, is slightly stronger than that of structure IIIb - which may be viewed as a hint of a metastable packing preference for IIIa, overcome by the contribution of a more stabilising Coulomb energy to the overall more favourable lattice energy of structure IIIb. Our studies have shown that the crystal colour is correlated with one of two molecular conformations which are different in energy, but that the less stable conformation can be stabilised by its host crystal lattice. Graphical abstractGraphical representation of the structural and colour change in the tribochromic compound (III).

Origami-inspired and deployable technology has become increasingly common in a variety of applications including satellite and antenna designs for space applications. The drive to utilize ultra-thin materials in the design of these deployable space structures has led to the development of membrane hinges. Membrane hinges show promise as an effective surrogate fold because of their potential advantages including requiring minimal volume and mass, allowing for small bending radii, and functioning without lubricant. Two challenges associated with membrane hinges include reliability after repeated cyclic loading and predictability of a large deployable with radially-unconstrained membrane hinges. The research presented includes the cyclic testing and a design analysis of membrane hinges in deployable systems. Additionally, demonstrations of membrane hinges in a variety of applications are included.

This thesis focuses on the comparison of numerical simulation and optical measurement of deformation of the turbinehousing made by Honeywell company. The numerical calculation performed by finite element method to simulate transient thermal load on the measured entity. Numerical result of the strain state of the body caused by temperature gradients. To verify the simulation is used an experimental digital correlation method VIC-3D. The thesis also mentioned the theoretical foundations of digital correlation methods and thermal analysis.

Este trabalho pretende estabelecer bases para a análise de estruturas correntes feitas em taipa de pilão. Esse material, constituído quase que somente por terra obtida no local da obra, tem todas as propriedades do que se chama uma construção sustentável, incluindo um mínimo de consumo de energia, se comparado as estruturas convencionais em aço e concreto. O texto é dividido em três temas principais. O primeiro trata de revisão da pouca literatura técnica existente sobre o assunto, incluindo a descrição das técnicas de construção e de seleção e preparo dos materiais. O segundo abrange a pesquisa feita pela autora no preparo e ensaio de corpos de prova do material, com a intenção de obter parâmetros que são o insumo para a análise propriamente dita de estruturas desse tipo. Esta análise é a terceira parte do trabalho, a qual consiste no processamento de modelos tridimensionais de elementos finitos de estruturas de construções hipotéticas em taipa de pilão. / This work intends to provide basis for the analysis of common structures built of rammed earth. This material, constituted almost entirely of earth obtained in the place where the building will stand, has all the properties of what is known as sustainable construction, including a minimal consume of energy, as compared to conventional steel or concrete structures. The text is divided in three main themes. The first reports the review the little existing technical literature on the subject, including the description of the building procedures and the selection and preparation of the materials. The second reports research conducted by the author on the preparation and testing of samples of the material, in order to obtain the parameters needed in the analysis of structures of this type. This is the third part of the work, consisting in the numerical analysis of three dimensional finite element models of hypothetical buildings made of rammed earth.

No description available.

Electronic structure calculation is an essential approach for determining the structure and function of molecules and is therefore of critical interest to physics, chemistry, and materials science. Of the various algorithms for calculating electronic structure, the pseudospectral method is among the fastest. However, the trade-off for its speed is more up-front programming and testing, and as a result, applications using the pseudospectral method currently lag behind those using other methods. In Part I of this dissertation, we first advance the pseudospectral method by optimizing it for an important application, polarized Raman spectroscopy, which is a well-established tool used to characterize molecular properties. This is an application of particular importance because often the easiest and most economical way to obtain the polarized Raman spectrum of a material is to simulate it; thus, utilization of the pseudospectral method for this purpose will accelerate progress in the determination of molecular properties. We demonstrate that our implementation of Raman spectroscopy using the pseudospectral method results in spectra that are just as accurate as those calculated using the traditional analytic method, and in the process, we derive the most comprehensive formulation to date of polarized Raman intensity formulas, applicable to both crystalline and isotropic systems. Next, we apply our implementation to determine the orientations of crystalline oligothiophenes --- a class of materials important in the field of organic electronics --- achieving excellent agreement with experiment and demonstrating the general utility of polarized Raman spectroscopy for the determination of crystal orientation. In addition, we derive from first-principles a method for using polarized Raman spectra to establish unambiguously whether a uniform region of a material is crystalline or isotropic. Finally, we introduce free, open-source software that allows a user to determine any of a number of polarized Raman properties of a sample given common output from electronic structure calculations. In Part II, we apply the pseudospectral method to other areas of scientific importance requiring a deeper understanding of molecular structure and function. First, we use it to accurately determine the frequencies of vibrational tags on biomolecules that can be detected in real-time using stimulated Raman spectroscopy. Next, we evaluate the performance of the pseudospectral method for calculating excited-state energies and energy gradients of large molecules --- another new application of the pseudospectral method --- showing that the calculations run much more quickly than those using the analytic method. Finally, we use the pseudospectral method to simulate the bottleneck process of a solar cell used for water splitting, a promising technology for converting the sun's energy into hydrogen fuel. We apply the speed of the pseudospectral method by modeling the relevant part of the system as a large, explicitly passivated titanium dioxide nanoparticle and simulating it realistically using hybrid density functional theory with an implicit solvent model, yielding insight into the physical nature of the rate-limiting step of water splitting. These results further validate the particularly fast and accurate simulation methodologies used, opening the door to efficient and realistic cluster-based, fully quantum-mechanical simulations of the bottleneck process of a promising technology for clean solar energy conversion. Taken together, we show how both polarized Raman spectroscopy and the pseudospectral method are effective tools for analyzing the structure and function of important molecular systems.

Este trabalho pretende estabelecer bases para a análise de estruturas correntes feitas em taipa de pilão. Esse material, constituído quase que somente por terra obtida no local da obra, tem todas as propriedades do que se chama uma construção sustentável, incluindo um mínimo de consumo de energia, se comparado as estruturas convencionais em aço e concreto. O texto é dividido em três temas principais. O primeiro trata de revisão da pouca literatura técnica existente sobre o assunto, incluindo a descrição das técnicas de construção e de seleção e preparo dos materiais. O segundo abrange a pesquisa feita pela autora no preparo e ensaio de corpos de prova do material, com a intenção de obter parâmetros que são o insumo para a análise propriamente dita de estruturas desse tipo. Esta análise é a terceira parte do trabalho, a qual consiste no processamento de modelos tridimensionais de elementos finitos de estruturas de construções hipotéticas em taipa de pilão. / This work intends to provide basis for the analysis of common structures built of rammed earth. This material, constituted almost entirely of earth obtained in the place where the building will stand, has all the properties of what is known as sustainable construction, including a minimal consume of energy, as compared to conventional steel or concrete structures. The text is divided in three main themes. The first reports the review the little existing technical literature on the subject, including the description of the building procedures and the selection and preparation of the materials. The second reports research conducted by the author on the preparation and testing of samples of the material, in order to obtain the parameters needed in the analysis of structures of this type. This is the third part of the work, consisting in the numerical analysis of three dimensional finite element models of hypothetical buildings made of rammed earth.

[Truncated abstract] Areal bone mineral density (BMD) is measured routinely in the clinic by a quantitative radiological technique, dual-energy X-ray absorptiometry (DXA). BMD is used widely to assess non-invasively but indirectly the mechanical fragility of bone and consequently is able to predict fracture risk. While BMD correlates well with in vitro measurements of bone strength it does not directly measure a mechanical property; half of incident minimally traumatic fractures in women occur with BMD values above the World Health Organisation defined threshold for osteoporosis. This arises partly because the mechanical strength of bone is dependent on its structural geometry and material strength as well as bone mineral mass. Essentially, bones fracture when load stresses exceed the mechanical capacity of the material to withstand them. The structural geometry (i.e., the amount of bone tissue and its complex three-dimensional arrangement within the macroscopic bone envelope) defines the stresses produced by a given load, while the intrinsic load capacity of the material is defined by the composition and microstructure of the bone tissue itself. Hip structural analysis (HSA) is a technique that elucidates the structural geometric component of bone strength; essentially combining information available from conventional DXA images of the proximal femur with a biomechanical beam model based on the stresses arising in a combination of pure bending and axial compression. A version of HSA has recently been released commercially, and has obtained US Food and Drug Administration approval for its clinical application. ... Given the acknowledged limitations of the HSA method when applied to 2-D projection images, a 3-D approach to structural geometry, using imaging modalities such as pQCT and QCT or a recently introduced version of DXA that mimics QCT, is indicated for the future. With that in mind and the possibility of the anthropometric phantom being adopted for future accuracy and precision assessments, improvements in the design of this phantom are recommended. Studies to better understand and verify Contents v the relevance of the 'local buckling' phenomenon as a structural geometric factor in the genesis of macro-fractures are also recommended. In summary, it is essential that superior (compared to BMD) non-invasively determined clinical predictors of bone fragility leading to fracture be investigated. Structural geometric variables are potential candidates. This has led to consideration of; (i) the need to progress beyond BMD for a more sensitive and specific bone strength measurement; (ii) theoretical advantages of structural geometry over BMD; (iii) limitations of the current HSA technique based on DXA, including those introduced by its restrictive assumptions; (iv) the value of HSA in longitudinal studies, exemplified by the 'normal' but rapid skeletal changes seen in human lactation, with possible implications for an analogous study of the menopause; and (v) an investigation, using a custom-designed anthropometric phantom, of the adaptation of HSA to certain emerging imaging modalities and methods able to resolve bone structural geometry in three dimensions.

Therapeutic Assessment (TA) is a hybrid of assessment and therapy techniques in which assessors actively collaborate with clients during an individualized assessment. TA is centered around client assessment questions and provides a safe environment where clients can create shifts in their ‘story’ of self. More specifically, TA with children and their parents has demonstrated more confident parenting and parents’ better understanding of their child’s difficulties, while children have shown decreased problem behaviors and improved social/emotional functioning. The theoretical framework behind TA emphasizes the importance of the interpersonal interactions between the assessor and client, such as the development of a strong assessor client relationship and collaboration. These interpersonal processes are conceptualized as catalysts for greater depth of parent investment in the assessment and deeper levels of feedback results. The need for greater parent involvement and partnership in child mental health services is increasingly recognized in the client/parent satisfaction literature. Parent feedback to child mental health services is most often acquired through satisfaction questionnaires. However, the satisfaction literature has well known limitations, specifically a lack of unifying theory and methodological issues in scale development. Parent satisfaction research indicates that interpersonal experiences are more related to satisfaction than outcomes or client characteristics, and that more psychometrically sound measures are needed. Currently, satisfaction surveys do not provide a detailed understanding of parents’ experiences to inform practice and research. The current study outlines the development of the Parent Experience of Assessment Scale (PEAS). The PEAS is anchored in the theoretical orientation of TA and provides a more quantifiable measure of hypothesized underlying TA constructs. Moreover, the development of the PEAS uses advanced statistical techniques, such as Confirmatory Factor Analysis and invariance testing, to provide a higher level of psychometric rigor. The resulting scale consists of 24 items divided among 5 subscales with demonstrated relationships to general satisfaction. Structural equation modeling provides insight via direct and indirect effects among the PEAS subscales and their relationship to general satisfaction. Through the development of the PEAS, this study provides empirical evidence and support for TA theory and a more nuanced understanding of parent experiences related to satisfaction. / text