Enhancing Coral Reef Resilience and Restoration Success: Lessons Learned from Laolao Bay, Saipan and Maunalua Bay, Oahu.

Ph.D. Thesis. University of Hawaiʻi at Mānoa 2018

ACRF Data Collection and Processing Infrastructure

We present a description of the data flow from measurement to long-term archive. We also discuss data communications infrastructure. The data handling processes presented include collection, transfer, ingest, quality control, creation of Value-Added Products (VAP), and data archiving

Deuterium NMR Studies of Segmental Dynamics of Anopore-Adsorbed Poly(Methyl Acrylate)

Studies of segmental dynamics of polymers at interfaces provide a basis for understanding the properties of composite materials. Interfacial phenomena in multi-phase systems need to be understood as devices made from multi-phase polymeric systems become smaller. Various techniques have been used to investigate interfacial polymers at the air-polymer-solid interface; for example, ellipsometry,1 X-ray,2 and neutron reflectometry.3 These techniques typically characterize the structure (often the thickness) of the polymer layer and are normally used to determine the glass-transition temperature (Tg) through a break in the thicknesstemperature curve. There have been a few reports where the dynamics of polymers at the surface-air interface has been probed directly or inferred by NMR4 or ESR5. Using deuterium quadrupolar echo techniques on poly(vinyl acetate)-d3, Blum et al.6 showed that a deuterated methyl group could be used to probe the dynamics of adsorbed polymers. Lin and Blum7,8 observed that molecular mass affected segmental dynamics in both bulk and silica-adsorbed poly(methyl acrylate) (PMA-d3). As temperature increased, both high and low molecular mass samples showed increased motional rates, with significantly faster motional rates in the high molecular mass samples. They also reported that lower adsorbed amounts exhibited relatively slower motional rates than higher adsorbed amounts did. Anopore is an inorganic membrane that is produced by anodic oxidation of aluminum.9 Since the process is electrochemical, the conditions can be controlled and reproducible pore structures with narrow pore-size distributions can be obtained. They are available in 4.7 cm discs, 60 um thick, with 0.2 or 0.02 um diameter pore sizes. The anopore membranes are usually used for filtration purposes. Anopore has been used as a confining substrate in studies of polymer adsorption.10-12 However, not much is known about the adsorption mechanism or the state of the polymer in them. In this paper, we examine the adsorption of PMA-d3 on anopore by 2H NMR. We look at the process of adsorption, the effect of adsorbed amounts, and the effect of pore size. The results show little difference in the effect of pore size, or adsorbed amounts on the mobilities of PMA-d3 segments

Dynamics of Adsorbed PMA-d₃ - Effect of Substrate

In the last few years, our group has focused much of our attention on studying the dynamics of polymers adsorbed at interfaces. Much of our work, to date has been on labeled poly(vinyl acetate)-d3 (PVAc-d3)1 and poly(methyl acrylate)-d3 (PMA-d3)2 on silica. We have been able to probe the effects of adsorbed amount,3 molecular mass,4,5 and the effect of overlayer.6 These studies have provided a view of the adsorbed polymer consistent with a motional gradient in the layer with the more mobile segments being those at the air-polymer interface and the less-mobile segments at the substratepolymer interface. However, we have not probed the effect of the interaction with the substrate. In the present work, we describe the dynamics of PMA-d3 adsorbed on different substrates with a focus on how the substrate affects the dynamics of the polymer. In particular, we examine silica- and alumina-based substrates. For silica we explored the behavior of PMA-d3 on Cab-O-Sil silica, both in its native and hydrophobic form. For alumina we have probed the behavior on both alumina powder and also anopore membranes. We find that the dynamics of the adsorbed polymer depends on the nature of the substrate

Deuterium NMR Studies of Bulk and Silica-Absorbed Polystyrene

Thin polymer films are used in applications such as electronics, biomedical devices and coatings. As the trend to make the devices smaller continues, a film\u27s influence on a material\u27s overall properties becomes more prominent. Previous studies have shown that thin polymer films have characteristics slightly different from those of bulk polymers. Film behavior has been characterized by examining thermal expansion, diffusion, conformation, density and glass transitions. The dynamics of glassy polystyrene has been investigated using a wide variety of theoretical and experimental methods. Schaefer et al., using 13C NMR, reported that ~7% of phenyl rings in polystyrene undergo -flips. Using deuterium NMR on ring-deuterated polystyrene, E. Rossler, et al. determined that a powder pattern of a rigid solid is obtained at room temperature. At 383 K, two low intensity peaks are present in the middle of the powder pattern and, at 433 K, a Lorentzian line was found. While the broad powder pattern was characteristic of deuterated polystyrene with no chain motion, the two low intensity middle peaks were attributed to the phenyl rings undergoing -flips. Kulik and Prins also showed that the deuterium powder pattern for polystyrene contained two weak middle peaks.4 Upon altering the relaxation delay, Kulik et al. determined that, for a partially relaxed sample (short relaxation delay), the two middle peaks were dominant over the \u27outer horns\u27 but, when given enough time for complete relaxation, the converse is true. They concluded that the line shapes are superpositions of roughly two contributions from phenyl rings performing relatively slow and fast flipping motions. Zhao et al., using deuterium NMR on ring-deuterated polystyrene, found a strong dependence of the line shape on temperature and echo delay, indicating motion at the microsecond time scale at the temperatures studied. In this study, we investigate the dynamics of polystyrene in bulk and silica-adsorbed samples as temperatures approach the glass transition temperature (Tg)

Molecular Dynamics of Polystyrene Solutions in Microwave Fields

Equilibrium and nonequilibrium molecular dynamics simulation techniques were used to assess the influence of an applied microwave field on the dynamics of methylamine-methanol and methylamine-dimethylformamide (DMF) solutions bound within atactic polystyrene over a range of polymer densities from 35 to 96 wt % polymer. Atomistically detailed systems were studied, ranging from 3000 to 10 644 particles, using previously established potential models. Structural and dynamical properties were determined in the canonical (NVT) ensemble at 298 K. The simulated DMF self-diffusion coefficients in polystyrene solutions were compared with the zero-field experimental results established with pulsed-gradient spin-echo NMR spectrometry. A simulated external microwave field, with a rms electric field intensity of 0.1 V/Å, was applied to these systems and the simulated dynamical results over field frequencies up to 104 GHz were compared with the zero-field values. Simulated evidence of athermal effects on the diffusive characteristics of these mixtures is reported

A Comparative Study of the Properties of Polar and Nonpolar Solvent/Solute/Polystyrene Solutions in Microwave Fields Via Molecular Dynamics

The influence of an applied microwave field on the dynamics of methylamine-dichloromethane (DCM) mixtures bound within atactic polystyrene (a-PS) over a range of polymer densities from 30 to 94 wt % polymer was examined using atomistic molecular dynamics simulations. This study is an extension of previous studies on methylamine transport in relatively polar polystyrene solutions of methanol and dimethylformamide [M. J. Purdue et al., J. Chem. Phys. 124, 204904 (2006)]. A direct comparison is made across the three types of polystyrene solutions. Consideration is given to both solvent and reagent transport within the polymer solutions under zero-field conditions and in an external electromagnetic field in the canonical ensemble (NVT) at 298.0 K. Various frequencies up to 104 GHz and a rms electric field intensity of 0.1 V/Å were applied. The simulation studies were validated by comparison of the simulated zero-field self-diffusion coefficients of DCM in a-PS with those obtained using pulsed-gradient spin-echo NMR spectrometry. Athermal effects of microwave fields on solute transport behavior within polymer solutions are discussed

A video life-world approach to consultation practice: The relevance of a socio-phenomenological approach

This article discusses the [development and] use of a video life-world schema to explore alternative orientations to the shared health consultation. It is anticipated that this schema can be used by practitioners and consumers alike to understand the dynamics of videoed health consultations, the role of the participants within it and the potential to consciously alter the outcome by altering behaviour during the process of interaction. The study examines health consultation participation and develops an interpretative method of analysis that includes image elicitation (via videos), phenomenology (to identify the components of the analytic framework), narrative (to depict the stories of interactions) and a reflexive mode (to develop shared meaning through a conceptual framework for analysis). The analytic framework is derived from a life-world conception of human mutual shared interaction which is presented here as a novel approach to understanding patient-centred care. The video materials used in this study were derived from consultations in a Walk-in Centre (WiC) in East London. The conceptual framework produced through the process of video analysis is comprised of different combinations of movement, knowledge and emotional conversations that are used to classify objective or engaged WiC health care interactions. The videoed interactions organise along an active or passive, facilitative or directive typical situation continuum illustrating different kinds of textual approaches to practice that are in tension or harmony. The schema demonstrates how practitioners and consumers interact to produce these outcomes and indicates the potential for both consumers and practitioners to be educated to develop practice dynamics that support patient-centred care and impact on health outcomes

Selecting social work students:lessons from research in Scotland

The issue of selection of students to social work programmes is one that remains highly contested. While it is clear that there is no single way of choosing the next generation of social work students, nevertheless, there are a number of strongly held beliefs about what ‘best practice’ means in this fraught field. These can be difficult to challenge, and even harder to shift, in spite of contrary evidence. This paper presents research conducted in Scotland in 2016 as part of the Scottish Government-sponsored Review of Social Work Education. The research set out to consider what selection processes were being used in Scotland and why; more fundamentally, it sought to explore the views of those involved in social work education alongside evidence about the outcomes of the selection processes (that is, data on student retention and success). The article concludes that while there is little evidence that one method of selection to social work programmes is intrinsically better than another, issues of fairness and transparency in selection, as well as diversity, remain pressing

О неустойчивости решений динамических уравнений на временной шкале

В роботi наведено результати аналiзу нестiйкостi динамiчних рiвнянь на часовiй шкалi. Застосовнiсть отриманого результату iлюструється на прикладi системи другого порядку.We present new results on the instability for dynamic equations on time scales. To demonstrate the applicability, we use some examples of dynamic equations of the second order