Sound transmission through lightweight parallel plates

This thesis examines the transmission of sound through lightweight parallel plates, (plasterboard double wall partitions and timber floors). Statistical energy analysis was used to assess the importance of individual transmission paths and to determine the overall performance. Several different theoretical models were developed, the choice depending on the frequency range of interest and method of attachment of the plates, whether point or line, to the structural frame. It was found that for a line connected double wall there was very good agreement between the measured and predicted results, where the dominant transmission path was through the frame and the cavity path was weak. The transition frequency where the coupling changes from a line to a point connection is when the first half wavelength is able to fit between the spacings of the nails. For point connected double walls, where the transmission through the frame was weaker than for line connection, the cavity path was dominant unless there was absorption present. When the cavity was sufficiently deep, such that it behaved more like a room, the agreement between the measured and predicted results was good. As the cavity depth decreases the plates of the double wall are closer together and the agreement between the measured and predicted results were not as good. Detailed experiments were carried out to determine the transmission into the double wall cavities and isolated cavities. It was found that the transmission into an isolated cavity could be predicted well. However, for transmission into double wall cavities the existing theories could not predict transmission accurately when the cavity depth was small. Extensive parametric surveys were undertaken to analyse changes to the sound transmission through these structures when the material or design parameters are altered. The SEA models are able to identify the dominant mechanisms of transmission and will be a useful design tool in the design of lightweight partitions and timber floors.Engineering and Physical Sciences Research Council (EPSRC)Defence Evaluation Research Agency (DERA

Poster 279 Radial Neuropathy Exacerbated by Ligamentous Laxity in Pregnancy and by Chemotherapy: A Case Report

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146835/1/pmrjs251.pd

Poster 254 Outcomes of Acute Inpatient Rehabilitation for Chronic Graft‐Versus‐Host‐Disease (cGVHD)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147174/1/pmr2s174b.pd

Poster 481 Metastatic Crohn Disease Manifesting as Skin Ulcerations in a Stroke Patient With Quadriplegia: A Case Report

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146877/1/pmr2s343.pd

Closing the Gap Between Watershed Modeling, Sediment Budgeting, and Stream Restoration

The connection between stream restoration and sediment budgeting runs both ways: stream restoration is proposed as a means to reduce sediment yields, but an accurate understanding of sediment supply is necessary to design an effective project. Recent advances in monitoring technology, geochemical techniques, high-resolution topography data, and numerical modeling provide new opportunities to estimate sediment erosion, transport, and deposition rates; upscale them in a geomorphically relevant fashion; and synthesize sediment dynamics at watershed scales. For practical application at large scale, watershed models used to predict yield often do not resolve lower-order channels, leaving an essential “blind spot” regarding sediment processes. We illustrate the challenges and emerging approaches for estimating sediment budgets using examples from two very different physiographic settings: the Mid-Atlantic Piedmont and the agricultural plains of southern Minnesota. We highlight common challenges and themes in defining an effective watershed sediment model. In both cases, reliable estimates of sediment yield depend essentially on the accurate identification of sediment sources and sinks and, hence, require careful delineation of landscape units and identification of dominant sediment sources and sinks. The primary elements needed to bridge the gap between sediment budgeting, watershed modeling, and stream restoration are (1) specificity regarding location, mechanism, and rates of erosion, (2) accurate accounting of sediment storage, (3) appropriate methods for upscaling local observations, (4) efficient means for incorporating multiple lines of evidence to constrain budget estimates, and (5) stream restoration methods that incorporate sediment supply in assessment and design procedures

Mismorphism: a Semiotic Model of Computer Security Circumvention (Extended Version)

In real world domains, from healthcare to power to finance, we deploy computer systems intended to streamline and improve the activities of human agents in the corresponding non-cyber worlds. However, talking to actual users (instead of just computer security experts) reveals endemic circumvention of the computer-embedded rules. Good-intentioned users, trying to get their jobs done, systematically work around security and other controls embedded in their IT systems. This paper reports on our work compiling a large corpus of such incidents and developing a model based on semiotic triads to examine security circumvention. This model suggests that mismorphisms---mappings that fail to preserve structure---lie at the heart of circumvention scenarios; differential perceptions and needs explain users\u27 actions. We support this claim with empirical data from the corpus

A retrospective investigation into the occurrence and human exposure to polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins and furans (PCDD/Fs) and PCBs through cod liver products (1972–2017)

A retrospective analysis of a number of historical medicinal grade cod-liver oil samples produced in Northern Europe revealed relatively high contamination levels of PCNs, PCDD/Fs and PCBs. The total toxic equivalence (TEQ) associated with PCDD/Fs, dl-PCBs and PCNs was in the range 95 to 427 pg g-1 for Baltic cod-liver oils and from 70 to 148 pg g-1 for oils sourced from the North Atlantic. The corresponding range for canned cod liver products (Baltic Sea) sampled in 2017 ranged from 52 to 104 pg g-1 fat (33 to 34 pg g-1 ww). The contribution from PCBs to the overall TEQ toxicity was around 3 to 6-fold higher than from PCDD/Fs and ranged from 24 to 318 pg TEQ g-1ww. The estimated summed TEQ intakes of PCDD/Fs, dl-PCBs and dl-PCNs resulting from the consumption of the daily recommended doses was highest for the Baltic cod-liver oils ranging from 16 to 293 pg kg-1 body mass (bm) day-1 for an adult, 20 to 183 pg kg-1 bm day-1 for a teenager and 15 to 131 pg kg-1 bm day-1 for a child. The contribution to daily adult TEQ intake from PCNs alone, although relatively small is estimated to contribute up to 5-fold above the recent EFSA proposed TWI of 2 pg kg-1 bm. The results indicate that although currently produced fish oils may undergo rigorous purification procedures and show low contaminant levels, cod livers sourced from the Baltic and consumed locally, continue to contribute substantially to the dietary intake of these contaminants

Ampliando a brecha: A desigualdade na distribuição de recursos para a educação científica nos níveis K-12

Inequalities in educational opportunity are well documented. Regardless of the nature of the disadvantage—low income, underrepresented minority status, or prior achievement—students from backgrounds associated with a given disadvantage have less access to educational opportunities. In this article, we use data from the 2012 National Survey of Science and Mathematics Education to explore how resources are allocated for science instruction specifically. We focus on how three kinds of resources—well-prepared teachers, material resources, and instruction itself—are allocated to classes that are homogeneously grouped by prior achievement level. Regardless of the resource, we find that classes of students with low prior achievement (as perceived by their teachers) have less access. Some of the differences are striking, particularly regarding access to material resources, while others are more subtle. There is also evidence that some policies do not impact teachers equally. For example, time allowed for teacher professional development is perceived differently by teachers in terms of its impact depending on the achievement level of students in the class. The study supports the assertion that what is known about ability grouping in general applies in science instruction specifically. When students with low prior achievement are grouped together, their classes have less access to critical resources for science learning opportunities, potentially widening the gap between them and their higher-achieving peers.Las desigualdades en las oportunidades educativas están bien documentadas. Independientemente de la naturaleza de la desventaja -- baja renta, condición de minoría subrepresentada, o de logros anteriores-- estudiantes asociados con alguna condición de desventaja tienen menos acceso a oportunidades educativas. En este artículo, utilizamos datos de la Encuesta Nacional  de Ciencia y Educación Matemática de 2012 para explorar cómo se asignan los recursos para la enseñanza de las ciencias. Nos centramos en cómo tres tipos de recursos -maestros bien preparados, recursos materiales, y la instrucción en sí, se asignan a las clases que se agrupan homogéneamente por nivel de logro anterior. Independientemente del recurso, nos encontramos con que las clases de estudiantes con bajo rendimiento previo (según la percepción de sus maestros) tienen menos acceso. Algunas de las diferencias son sorprendentes, sobre todo con respecto al acceso a los recursos materiales, mientras que otras son más sutiles. También hay evidencia de que algunas políticas no afectan a los docentes por igual. Por ejemplo, el tiempo permitido para el desarrollo profesional de los docentes que se percibe de manera diferente por los profesores en términos de su impacto en función del nivel de logro de los estudiantes en la clase. El estudio apoya la afirmación de que lo que se sabe acerca de la capacidad de agrupación en general se aplica en la enseñanza de la ciencia en particular. Cuando los estudiantes con bajo rendimiento son agrupados, sus clases tienen menos acceso a los recursos críticos para ampliar las oportunidades de aprendizaje de ciencias, lo que podría incrementar la brecha entre ellos y sus compañeros de mayores logros educativos.As desigualdades de oportunidades educacionais estão bem documentadas. Independentemente da natureza da desvantagem - baixa renda, status de minoria sub-representada ou resultados anteriores - estudantes associados a uma condição de desvantagem têm menos acesso a oportunidades educacionais. Neste artigo, usamos dados da Pesquisa Nacional de Ciência e Educação Matemática de 2012 para explorar a forma como os recursos são alocados para a educação científica. Nós nos concentramos em três tipos de- recursos --professores bem preparados, recursos materiais, e da própria instrução, e como são atribuídos a classes agrupados por nível de resultados anteriores. Independentemente da aplicação, verificamos que as turmas de alunos com baixo aproveitamento anterior (pela percepção dos professores) têm menos acesso. Algumas das diferenças são marcantes, especialmente no que diz respeito ao acesso a recursos materiais, enquanto outros são mais sutis. Há também evidências de que algumas políticas não afetam docentes da mesma maneira. Por exemplo, o tempo permitido para o desenvolvimento profissional de professores é percebido de forma diferente pelos professores em termos do seu impacto sobre o nível de desempenho do aluno na sala de aula. O estudo apoia o que se sabe geralmente sobre as politicas de agrupamento aplicado no ensino da ciência em particular. Quando os alunos de baixo desempenho são agrupados, suas aulas têm menos acesso a recursos essenciais para aumentar as oportunidades de aprendizagem das ciências, o que poderia aumentar a distância entre eles e os seus pares mais alto nível de instrução

Molecular orbital calculations of two-electron states for P donor solid-state spin qubits

We theoretically study the Hilbert space structure of two neighbouring P donor electrons in silicon-based quantum computer architectures. To use electron spins as qubits, a crucial condition is the isolation of the electron spins from their environment, including the electronic orbital degrees of freedom. We provide detailed electronic structure calculations of both the single donor electron wave function and the two-electron pair wave function. We adopted a molecular orbital method for the two-electron problem, forming a basis with the calculated single donor electron orbitals. Our two-electron basis contains many singlet and triplet orbital excited states, in addition to the two simple ground state singlet and triplet orbitals usually used in the Heitler-London approximation to describe the two-electron donor pair wave function. We determined the excitation spectrum of the two-donor system, and study its dependence on strain, lattice position and inter donor separation. This allows us to determine how isolated the ground state singlet and triplet orbitals are from the rest of the excited state Hilbert space. In addition to calculating the energy spectrum, we are also able to evaluate the exchange coupling between the two donor electrons, and the double occupancy probability that both electrons will reside on the same P donor. These two quantities are very important for logical operations in solid-state quantum computing devices, as a large exchange coupling achieves faster gating times, whilst the magnitude of the double occupancy probability can affect the error rate.Comment: 15 pages (2-column

Integrating Function‐Directed Treatments into Palliative Care

The growing acceptance of palliative care has created opportunities to increase the use of rehabilitation services among populations with advanced disease, particularly those with cancer. Broader delivery has been impeded by the lack of a shared definition for palliative rehabilitation and a mismatch between patient needs and established rehabilitation service delivery models. We propose the definition that, in the advanced cancer population, palliative rehabilitation is function‐directed care delivered in partnership with other clinical disciplines and aligned with the values of patients who have serious and often incurable illnesses in contexts marked by intense and dynamic symptoms, psychological stress, and medical morbidity to realize potentially time‐limited goals. Although palliative rehabilitation is most often delivered by inpatient physical medicine and rehabilitation consultation/liaison services and by physical therapists in skilled nursing facilities, outcomes in these settings have received little scrutiny. In contrast, outpatient cancer rehabilitation programs have gained robust evidentiary support attesting to their benefits across diverse settings. Advancing palliative rehabilitation will require attention to historical barriers to the uptake of cancer rehabilitation services, which include the following: patient and referring physicians’ expectation that effective cancer treatment will reverse disablement; breakdown of linear models of disablement due to presence of concurrent symptoms and psychological distress; tension between reflexive palliation and impairment‐directed treatment; palliative clinicians’ limited familiarity with manual interventions and rehabilitation services; and challenges in identifying receptive patients with the capacity to benefit from rehabilitation services. The effort to address these admittedly complex issues is warranted, as consideration of function in efforts to control symptoms and mood is vital to optimize patients’ autonomy and quality of life. In addition, manual rehabilitation modalities are effective and drug sparing in the alleviation of adverse symptoms but are markedly underused. Realizing the potential synergism of integrating rehabilitation services in palliative care will require intensification of interdisciplinary dialogue.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146938/1/pmr2s335.pd