Seismic Anisotropy of Temperate Ice in Polar Ice Sheets

We present a series of simple shear numerical simulations of dynamic recrystallization of two‐phase nonlinear viscous materials that represent temperate ice. First, we investigate the effect of the presence of water on the resulting microstructures and, second, how water influences on P wave (Vp) and fast S wave (Vs) velocities. Regardless the water percentage, all simulations evolve from a random fabric to a vertical single maximum. For a purely solid aggregate, the highest Vp quickly aligns with the maximum c‐axis orientation. At the same time, the maximum c‐axis development reduces Vs in this orientation. When water is present, the developed maximum c‐axis orientation is less intense, which results in lower Vp and Vs. At high percentage of water, Vp does not align with the maximum c‐axis orientation. If the bulk modulus of ice is assumed for the water phase (i.e., implying that water is at high pressure), we find a remarkable decrease of Vs while Vp remains close to the value for purely solid ice. These results suggest that the decrease in Vs observed at the base of the ice sheets could be explained by the presence of water at elevated pressure, which would reside in isolated pockets at grain triple junctions. Under these conditions water would not favor sliding between ice grains. However, if we consider that deformation dominates over recrystallization, water pockets get continuously stretched, allowing water films to be located at grain boundaries. This configuration would modify and even overprint the maximum c‐axis‐dependent orientation and the magnitude of seismic anisotropy

The Intentional Use of Service Recovery Strategies to Influence Consumer Emotion, Cognition and Behaviour

Service recovery strategies have been identified as a critical factor in the success of. service organizations. This study develops a conceptual frame work to investigate how specific service recovery strategies influence the emotional, cognitive and negative behavioural responses of . consumers., as well as how emotion and cognition influence negative behavior. Understanding the impact of specific service recovery strategies will allow service providers' to more deliberately and intentionally engage in strategies that result in positive organizational outcomes. This study was conducted using a 2 x 2 between-subjects quasi-experimental design. The results suggest that service recovery has a significant impact on emotion, cognition and negative behavior. Similarly, satisfaction, negative emotion and positive emotion all influence negative behavior but distributive justice has no effect

Particulate Fillers in Thermoplastics

The characteristics of particulate filled thermoplastics are determined by four factors: component properties, composition, structure and interfacial interactions. The most important filler characteristics are particle size, size distribution, specific surface area and particle shape, while the main matrix property is stiffness. Segregation, aggregation and the orientation of anisotropic particles determine structure. Interfacial interactions lead to the formation of a stiff interphase considerably influencing properties. Interactions are changed by surface modification, which must be always system specific and selected according to its goal. Under the effect of external load inhomogeneous stress distribution develops around heterogeneities, which initiate local micromechanical deformation processes determining the macroscopic properties of the composites

Anarchy? Nope. Just Probability.

The yearly NCAA march madness tournament is one of the most difficult prediction problems, as a perfect bracket is effectively impossible. However, predicting the outcomes of each individual game is a much more surmountable challenge. In my project I use free in-season and tournament data from Kaggle’s march machine learning mania challenge and from public advanced stats websites in an attempt to assign a win probability to each possible matchup in the 2023 March Madness tournament, as well as probabilities of each team to advance for each round through a hierarchical model. I have built multiple predictive models and will compare them and examine what is driving their differences

Examining the Relationship between Teacher Beliefs, Prekindergartener's Self-Regulation and Classroom Quality: Informing Professional Development Programs

The purpose of this convergent parallel, mixed methods study was to examine and explore the relationship between subjective teacher beliefs, classroom quality, and pre-kindergartener’s self-regulatory abilities within a publicly funded pre-kindergarten program. Teacher subjective beliefs (beliefs of classroom management, classroom practice, and beliefs of children) were studied operantly using Q-Methodology, in addition to, audio-recorded focus groups to explore the lived experience of teachers within the sample ( n = 20). Classroom quality was measured using the Classroom Assessment Scoring System (CLASS) and pre-kindergartener’s self-regulatory abilities were studied using pre/post proxy items from the Devereux Early Childhood Assessment for Preschoolers, Second Edition (DECA-P2). A criterion sort was created to determine correlation between trainer, coach, and model teacher beliefs sorts and teacher belief sorts. Data were separately collected and analyzed prior to intercepting for interpretation with priority assigned to the quantitative data. Non-parametric testing was employed with ranked beliefs, CLASS, and DECA-P2 distribution-free data. The following corroborated QUANqual results emerged: a) studying subjective beliefs operantly using Q-methodology provides researchers the ability to determine different and similar pure associations with constructs, b) in classroom coaching and training influence teacher beliefs about classroom management, practice, and children, teachers believe developing student’s social emotional competence, specifically, c) self-regulation is fundamental for pre-kindergarteners, teacher beliefs impact children’s self-regulatory growth, d) classroom quality is influenced by teacher beliefs regarding classroom management, specifically regard of student perspective, reviewing teacher beliefs operantly, e) studying beliefs operantly provides additional insights for coaches or trainers to specifically target constructs. This study recommends that future studies include a larger nationally based sample to explore and examine the relationship between teacher beliefs, classroom quality, and children’s ability to self-regulate. This study found that teachers beliefs, correlated with exemplars, effect the average change in self-regulatory abilities for prekindergaterners. The researcher recommends that future studies implement parametric testing with larger studies to determine the generalization of the effects

Deriving micro- to macro-scale seismic velocities from ice-core <i>c</i> axis orientations

One of the great challenges in glaciology is the ability to estimate the bulk ice anisotropy in ice sheets and glaciers, which is needed to improve our understanding of ice-sheet dynamics. We investigate the effect of crystal anisotropy on seismic velocities in glacier ice and revisit the framework which is based on fabric eigenvalues to derive approximate seismic velocities by exploiting the assumed symmetry. In contrast to previous studies, we calculate the seismic velocities using the exact c axis angles describing the orientations of the crystal ensemble in an ice-core sample. We apply this approach to fabric data sets from an alpine and a polar ice core. Our results provide a quantitative evaluation of the earlier approximative eigenvalue framework. For near-vertical incidence our results differ by up to 135 m s−1 for P-wave and 200 m s−1 for S-wave velocity compared to the earlier framework (estimated 1 % difference in average P-wave velocity at the bedrock for the short alpine ice core). We quantify the influence of shear-wave splitting at the bedrock as 45 m s−1 for the alpine ice core and 59 m s−1 for the polar ice core. At non-vertical incidence we obtain differences of up to 185 m s−1 for P-wave and 280 m s−1 for S-wave velocities. Additionally, our findings highlight the variation in seismic velocity at non-vertical incidence as a function of the horizontal azimuth of the seismic plane, which can be significant for non-symmetric orientation distributions and results in a strong azimuth-dependent shear-wave splitting of max. 281 m s−1 at some depths. For a given incidence angle and depth we estimated changes in phase velocity of almost 200 m s−1 for P wave and more than 200 m s−1 for S wave and shear-wave splitting under a rotating seismic plane. We assess for the first time the change in seismic anisotropy that can be expected on a short spatial (vertical) scale in a glacier due to strong variability in crystal-orientation fabric (±50 m s−1 per 10 cm). Our investigation of seismic anisotropy based on ice-core data contributes to advancing the interpretation of seismic data, with respect to extracting bulk information about crystal anisotropy, without having to drill an ice core and with special regard to future applications employing ultrasonic sounding

Investigating cold based summit glaciers through direct access to the glacier base: a case study constraining the maximum age of Chli Titlis glacier, Switzerland

Cold glaciers at the highest locations of the European Alps have been investigated by drilling ice cores to retrieve their stratigraphic climate records. Findings like the Oetztal ice man have demonstrated that small ice bodies at summit locations of comparatively lower altitudes may also contain old ice if locally frozen to the underlying bedrock. In this case, constraining the maximum age of their lowermost ice part may help to identify past periods with minimum ice extent in the Alps. However, with recent warming and consequent glacier mass loss, these sites may not preserve their unique climate information for much longer. Here we utilized an existing ice cave at Chli Titlis (3030 m), central Switzerland, to perform a case study for investigating the maximum age of cold-based summit glaciers in the Alps. The cave offers direct access to the glacier stratigraphy without the logistical effort required in ice core drilling. In addition, a pioneering exploration had already demonstrated stagnant cold ice conditions at Chli Titlis, albeit more than 25 years ago. Our englacial temperature measurements and the analysis of the isotopic and physical properties of ice blocks sampled at three locations within the ice cave show that cold ice still exists fairly unchanged today. State-of-the-art micro-radiocarbon analysis constrains the maximum age of the ice at Chli Titlis to about 5000 years before present. By this means, the approach presented here will contribute to a future systematic investigation of cold-based summit glaciers, also in the Eastern Alps

Crystal orientation fabric variations in cold alpine ice

We present first results of high-resolution measurements of the crystal orientation fabric of an Alpine ice core. These are compared with other ice-core parameters, in particular climate proxies, to investigate the genesis of rapid fabric changes to environmental conditions