A Role for Affect in the Future of Mathematics Education (With Thoughts on Intelligence)

A Review of: 1. Alan Schoenfeld, Heather Fink, Alyssa Sayavedra, Anna Weltman, & Sandra Zuñiga-Ruiz’s (2023) Mathematics Teaching on Target, Routledge, 164pp. ISBN (HB): 978-1-0324-4167-2; 2. Alan Schoenfeld, Heather Fink, Sandra Zuñiga-Ruiz, Siqi Huang, Xinyu Wei, & Brantina Chirinda’s (2023) Helping Students Become Powerful Mathematics Thinkers, Routledge, 272pp. ISBN (HB): 978-1-0324-4168-9

A computational investigation of the interaction of the collagen molecule with hydroxyapatite

This thesis presents the results of computer simulation studies of the interaction of the predominant molecules in the collagen protein with the hydroxyapatite mineral. Using a combination of computational techniques, quantum-mechanical methods based on the density functional theory (DFT) and molecular dynamics simulations based on interatomic potentials, we have investigated the interface between the collagen protein and the apatite mineral. First we have employed electronic structure techniques (DFT) to study a range of different binding modes of the amino acids glycine, proline and hydroxyproline, which are major constituents of the collagen I protein, at two important hydroxyapatite surfaces, (0001) and (0110) . We have performed full geometry optimizations of the hydroxyapatite surface with adsorbed amino acid molecules to obtain the optimum substrate/adsorbate structures and interaction energies. We have also used DFT to investigate the binding of a series of representative peptides containing hydrophobic side groups (proline), uncharged polar side groups (glycine and hydroxyproline), and charged polar side groups (lysine and hydroxylysine) to the hydroxyapatite (0001) and (0110) surfaces. This selection of adsorbates has given us the opportunity to study separately the interactions of the carboxylic acid and amine functional groups, as well as the effect of hydroxylation and the charges of the side group, on the strength of interaction with the surfaces. We have also investigated the same systems in an aqueous environment using classical molecular dynamics simulation, where we have calculated the energies and geometries of adsorption of the peptide at the surfaces of hydroxyapatite in competition with pre-adsorbed water. Finally, we have studied the onset of nucleation of the hydroxyapatite mineral at an entire collagen molecule in aqueous solution

Relationship Between Employee Involvement Management Practices and Burnout Among Military Mental Health Providers

This study will investigate the relationship between Employee Involvement Management Practices, Burnout, and work-related consequences of Burnout. The sample for this study was drawn from a population of Military Mental Health Providers in the United States Navy. Based on research information about work stress, direct service work, and the costs of interpersonal work, there is a strong potential for Burnout to occur among individuals working in such a setting. Burnout has been shown to lead to negative organizational consequences such as increased employee turnover, reduced organizational commitment, reduced job satisfaction, emotional exhaustion, and cynicism, all of which can result in reduced consistency and quality of care for patients. Employee Involvement Management Practices have shown a potential for moderating Burnout related issues such as organizational commitment, job satisfaction, and reduced turnover in other work settings. This study will assess subjects\u27 perception of Employee Involvement Management Practices at their work site, and will assess Burnout, Turnover Intentions, Organizational Commitment, and Job Satisfaction. The author\u27s hypothesis is that where Employee Involvement Management Practices are perceived, subjects will report lower scores of Burnout, lower Turnover Intentions, higher Organizational Climate, higher Organizational Commitment and higher Job Satisfaction. The Emotional Exhaustion section of the Maslach Burnout Inventory and Interview was used to assess Burnout. The Work Environment Scale Clarity and Control scales assessed attitudes about organizational climate. The Organizational Commitment Questionnaire was used to assess organizational commitment. Two questions drawn from the Organizational Commitment Questionnaire were used to assess respondents\u27 Turnover Intentions. The Employee Involvement Practices Scale was used to assess perceptions of Employee Involvement Management Practices at the respondents\u27 work site. The Job In General Index was used to assess respondents\u27 ratings of job satisfaction

“SHOULD WELLBEING BE THE SAME AS PERFECTION?” A CASE STUDY ON STUDENT WELLBEING IN HIGHER MATHEMATICS EDUCATION

Previous research has given the impression that reticent is our hunt for optimal teaching practices, educational goals, and nature of mathematical workings. In this regard, we have (seemingly) ended up with the following inquiries: What could the math classroom be for? and What has the math classroom been for? These two questions touch on the scary horns of two other charged philosophical dandruffs. Namely:“What are the aims of teaching mathematics?” and “What should be our objectives in learning it?” The term ‘positive education’ refers to an educational system engendering both the skills of positive wellbeing and traditional, academic achievement (Seligman et al., 2009). Many case studies—primarily in Australian schools—have been conducted. However, philosophical advancements in the wellbeing sciences indicate that wellbeing, as a construct, is context-dependent (Alexandrova, 2017). Conceptions of wellbeing may thus differ between social groups, geographies, and local cultures (Green et al., 2021; Jarden et al., 2021). In this thesis, I present a framework for understanding a novel construct in the mathematics education literature called mathematical wellbeing. This construct may be studied through a variety of lenses (public policy, sociology, mathematics, positive psychology, mathematics education, economics). I build on a few of these by investigating factors relevant to student mathematical wellbeing. I also offer ways to study this construct in a first-year, collegiate mathematics course

Theoretical Description of the Role of Halides, Silver, and Surfactants on the Structure of Gold Nanorods

Density functional theory simulations including dispersion provide an atomistic description of the role of different compounds in the synthesis of gold-nanorods. Anisotropy is caused by the formation of a complex between the surfactant, bromine, and silver that preferentially adsorbs on some facets of the seeds, blocking them from further growth. In turn, the nanorod structure is driven by the perferential adsorption of the surfactant, which induces the appearance of open {520} lateral facets

On Mott-Schottky analysis interpretation of capacitance measurements in organometal perovskite solar cells

Capacitance response of perovskite-based solar cells (PSCs) can be exploited to infer underlying physical mechanisms, both in the materials bulk and at outer interfaces. Particularly interesting is applying the depletion layer capacitance theory to PSCs, following common procedures used with inorganic and organic photovoltaic devices. Voltage-modulation of the depletion layer width allows extracting relevant parameters as the absorber defect density and built-in potential by means of the Mott-Schottky (MS) analysis. However, the uncritical use of the MS technique may be misleading and yields incorrect outcomes as a consequence of masking effects that accumulation capacitances, commonly observed in PSCs, produce on the measured capacitance value. Rules are provided here to select the measuring frequency that allows extracting depletion layer capacitance, and the voltage range in which it dominates, avoiding accumulation capacitive parasitic contributions. It is noted that the distinction of the depletion capacitance from the accumulation capacitance is only feasible in the case of perovskite layers containing significant defect density (∼1017 cm−3). It is confirmed that MS reproducibility is assured by hysteresis reduction at slow scan rates, and positive bias starting polarization. A complete procedure with specific checking points is provided here for consistent MS measurement and interpretation.We thank the Ministerio de Economía y Competitividad (MINECO) of Spain for financial support under Projects (MAT2013-47192-C3-1-R and MAT2016-76892-C3-1-R), and Generalitat Valenciana (Prometeo/2014/020). O.A. acknowledges Generalitat Valenciana for a Grant (GRISOLIAP2014/035). E.M.-M. thanks the Ramón y Cajal program from MINECO of Spain. SCIC at UJI are also acknowledged

Radial Singular Solutions to Semilinear Partial Differential Equations

We show the existence of countably many non-degenerate continua of singular radial solutions to a p-subcritical, p-Laplacian Dirichlet problem on the unit ball in R^N. This result generalizes those for the 2-Laplacian to any value p and extends recent work on the p-Laplacian by considering solutions both radial and singular

Switching Off Hysteresis in Perovskite Solar Cells by Fine‐Tuning Energy Levels of Extraction Layers

Lead halide perovskites often suffer from a strong hysteretic behavior on their j–V response in photovoltaic devices that has been correlated with slow ion migration. The electron extraction layer has frequently been pointed to as the main culprit for the observed hysteretic behavior. In this work three hole transport layers are studied with well‐defined highest occupied molecular orbital (HOMO) levels and interestingly the hysteretic behavior is markedly different. Here it is shown that an adequate energy level alignment between the HOMO level of the extraction layer and the valence band of the perovskite, not only suppresses the hysteresis, avoiding charge accumulation at the interfaces, but also degradation of the hole transport layer is reduced. Numerical simulation suggests that formation of an injection barrier at the organic/perovskite heterointerface could be one mechanism causing hysteresis. The suppression of such barriers may require novel design rules for interface materials. Overall, this work highlights that both external contacts need to be carefully optimized in order to obtain hysteresis‐free perovskite devices

Light Capacitances in Silicon and Perovskite Solar Cells

The framework on which the physics of silicon solar cells (SiSCs) is based robustly predicts dependences of capacitance on light intensity and voltage, even when most recent innovations are considered as the incorporation of transition metal oxide/Si heterojunctions. However, perovskite solar cells (PSCs) challenge most of the established paradigms, claiming for rethinking of known theories and devising novel models. Here we tackle this scenario by probing and comparing light-induced capacitance responses yielded by these two major exponents in the field of photovoltaic research. SiSCs light capacitances can be easily interpreted in the framework of the so-called chemical capacitance. Current approaches addressing the intriguing low-frequency capacitive features of PSCs are outlined and compared. Here, apparent similarities and differences between both photovoltaic technologies are highlighted, concerning the observation of light capacitances of chemical origin. It is concluded that, contrary to that occurring in SiSCs, bulk electronic chemical capacitances are not straightforwardly observed in PSCs. As capacitive features exhibited by PSCs are believed to be critically connected to performance degradation and device instability, future research and explanation directions are proposed here for advancing in the understanding of this challenging photovoltaic technology

Ionic charging by local imbalance at interfaces in hybrid lead halide perovskites

Identification of specific operating mechanisms becomes particularly challenging when mixed ionic-electronic conductors are used in optoelectronic devices. Ionic effects in perovskitesolar cells are believed to distort operation curves and possess serious doubts about their long term stability. Current hysteresis and switchable photovoltaic characteristics have been connected to the kinetics of ion migration. However, the nature of the specific ionic mechanism (or mechanisms) able to explain the operation distortions is still poorly understood. It is observed here that the local rearrangement of ions at the electrodeinterfaces gives rise to commonly observed capacitive effects. Charging transients in response to step voltage stimuli using thick CH3NH3PbI3 samples show two main polarization processes and reveal the structure of the ionic double-layer at the interface with the non-reacting contacts. It is observed that ionic charging, with a typical response time of 10 s, is a local effect confined in the vicinity of the electrode, which entails absence of net mobile ionic concentration (space-charge) in the material bulk.We thank financial support from MINECO of Spain under Project (MAT2013-47192-C3-1-R), and Generalitat Valenciana (Prometeo/2014/020). O.A. acknowledges Generalitat Valenciana for a Grant (GRISOLIAP2014/035)