Philosophical Lessons in The Honest-to-Goodness Truth

Our conception of what constitutes ethical behaviour starts young. As children, we take part in moral education and learn about what is right and wrong. Stories and parables are common tools used in teaching morals. Even though many children’s books have simple presentations of ethical arguments and positions, they can serve as springboards for further discussion and reflection on concepts related to ethics. The Honest-to-Goodness Truth, a children’s book by Pat McKissack does precisely that. The book posits that the truth should only be told when it is pleasant and not when it can be hurtful. This paper holds an alternative view to the one proposed, the view being that the truth should always be told, even when it is not nice. In particular, this paper argues that telling the truth should always be prioritised because lying to others denies them the ability to live in a way that is sensible and aligns with reality. Furthermore, not telling the truth out of consideration for others’ feelings denies them the chance to grow and improve themselves. This paper uses examples of common, everyday interpersonal interactions to illustrate how telling the truth regardless of others can reap a net benefit. Concealing the truth and being dishonest to protect their feelings, which might seem to be a good decision, but only in the short term. The paper concludes with an explanation of how we may circumvent certain issues with putting into practice this approach to honesty in our everyday lives

Thermal transport in two-dimensional materials and magnetic multilayers

Understanding thermal transport properties of materials is essential for both device applications and materials physics. Thermal conductivity and interface thermal conductance are important engineering parameters for small-scale device applications. In addition, microscopic quantities of how different types of heat carriers interact each other are of crucial importance that determine dynamics of charges and spins. In this thesis, I use ultrafast pump-probe metrology to experimentally investigate thermal transport properties in various materials systems. The first subject is two-dimensional materials having in-plane anisotropies, i.e., black phosphorus, WTe2, and ReS2, which were first prepared in 2D structures all in 2014. These materials are promising candidates for next-generation electronics and optoelectronics, and the knowledge of thermal transport properties is needed for engineering heat dissipation in devices. However, the low crystal symmetries complicate experimental evaluation of the properties. To determine thermal conductivity of the three materials along the three coordination axes, I use time-domain thermoreflectance (TDTR) of conventional geometry, where pump and probe beams are co-aligned, and TDTR of beam-offset geometry, where pump and probe beams on sample surface are spatially separated. The beam-offset TDTR allows to measure in-plane thermal conductivity along any arbitrary direction on sample planes but requires a significantly large thickness of a sample. I report the three-dimensional thermal conductivity of BP, WTe2, and ReS2, and their interface thermal conductance with metals. The results are discussed in terms of crystal structure, constituent elements, and atomic bonding strength, and compared with other high-symmetry two-dimensional materials. The second topic is non-equilibrium heat transport in Pt and Co. Laser-induced non-equilibrium in metals have been extensively studied for noble metals using transient reflectance. However, the interpretation of transient reflectance is not straightforward as reflectance is affected by temperatures of electrons and phonons, and lattice strains. Transition metals also behave differently from noble metals and thus require different theoretical explanations. I propose to use a four-atomic-layers-thick Co layer as a thermometer to probe non-equilibrium dynamics in metals. I first characterize the properties of Co, e.g., carrier coupling parameters between electrons, phonons, and magnons, by using time-resolved quadratic and linear magneto-optical Kerr effects (TR-QMOKE and TR-MOKE, respectively) on 10-nm-thick and sub-nm-thick Co layers, respectively. Then I use sub-nm-thick Co layers embedded in much thicker Pt layers to investigate non-equilibrium heat transport in Pt. The fast magnetization dynamics of the ultrathin Co layers allows to isolate the electronic temperature at a precise location in Pt/Co/Pt trilayers with sub-picosecond time-resolution. I demonstrate that a model based on the diffusive transport of heat by electrons and the exchange of heat between excitations of electrons, phonons, and magnons consistently explains the temperature evolutions in Pt with different thicknesses, 2−42 nm. Lastly, I study thermal transport properties of magnetic tunnel junctions (MTJs). MTJs show interesting charge and spin dynamics when they are subject to temperature gradient, such as the tunnel-magneto Seebeck effect and spin Seebeck tunneling. To harness the thermally induced spin behaviors, it is essential to accurately describe the temperature profiles across an MTJ structure while the challenge is to determine the temperature drop across an oxide tunnel barrier. In this work, I use a Co or CoFeB electrode layer in an MTJ as a thermometer and determine the effective thermal conductivity across oxide tunnel barriers, MgO and MgAl2O4

Analysis of ultrafast magnetization switching dynamics in exchange-coupled ferromagnet-ferrimagnet heterostructures

Magnetization switching in ferromagnets has so far been limited to the current-induced spin-orbit-torque effects. Recent observation of helicity-independent all-optical magnetization switching in exchange-coupled ferromagnet ferrimagnet heterostructures expanded the range and applicability of such ultrafast heat-driven magnetization switching. Here we report the element-resolved switching dynamics of such an exchange-coupled system, using a modified microscopic three-temperature model. We have studied the effect of i) the Curie temperature of the ferromagnet, ii) ferrimagnet composition, iii) the long-range RKKY exchange-coupling strength, and iv) the absorbed optical energy on the element-specific time-resolved magnetization dynamics. The phase-space of magnetization illustrates how the RKKY coupling strength and the absorbed optical energy influence the switching time. Our analysis demonstrates that the threshold switching energy depends on the composition of the ferrimagnet and the switching time depends on the Curie temperature of the ferromagnet as well as RKKY coupling strength. This simulation anticipates new insights into developing faster and more energy-efficient spintronics devices

The Effects of Cognitive Appraisal and Emotion on Consumer Behavior: The Critical Role of Recollection in the Luxury Cruise Setting

Abstract de la ponencia[EN] The purposes of this study were: (1) to integrate the cognitive appraisal theory and script theory; (2) to examine the bonding character of recollection; and (3) to assess the relationships between consumers ‘appraisals, positive/negative emotions, recollection, storytelling and repurchase intention. A review of previous studies revealed 14 theoretical hypotheses. The proposed hypotheses were tested utilizing data collected from 300 luxury cruise passengers. Confirmatory factor analysis and structural equation modeling were utilized to test the proposed theoretical relationships. According to the results, this work was the first to integrate the cognitive appraisal approach and script theory and also depicted a new angle from which marketers can better understand cruise travelers’ behaviorJoo, E.; Shin, H.; Kim, I.; Choi, J.; Jang, J.; Hyun, S. (2016). The Effects of Cognitive Appraisal and Emotion on Consumer Behavior: The Critical Role of Recollection in the Luxury Cruise Setting. En CARMA 2016: 1st International Conference on Advanced Research Methods in Analytics. Editorial Universitat Politècnica de València. 167-167. https://doi.org/10.4995/CARMA2016.2015.3135OCS16716

From the First Coeds to Our First Woman President - Why Gender Matters at DePauw

Gender has long been an important issue at DePauw, from the first women students who were admitted in 1867 to our first woman president over 150 years later. In this presentation, we will take a close look at the impetus for creating a gender resource center in 2004 and what current students need in 2021. Join us as we share how the programs, services and advocacy of the DePauw Women\u27s Center work to provide relevant resources and how we can continue to educate, celebrate and advocate into the future

Visualization of multifractal superconductivity in a two-dimensional transition metal dichalcogenide in the weak-disorder regime

Eigenstate multifractality is a distinctive feature of non-interacting disordered metals close to a metal-insulator transition, whose properties are expected to extend to superconductivity. While multifractality in three dimensions (3D) only develops near the critical point for specific strong-disorder strengths, multifractality in 2D systems is expected to be observable even for weak disorder. Here we provide evidence for multifractal features in the superconducting state of an intrinsic weakly disordered single-layer NbSe$_2$ by means of low-temperature scanning tunneling microscopy/spectroscopy. The superconducting gap, characterized by its width, depth and coherence peaks' amplitude, shows a characteristic spatial modulation coincident with the periodicity of the quasiparticle interference pattern. Spatial inhomogeneity of the superconducting gap width, proportional to the local order parameter in the weak-disorder regime, follows a log-normal statistical distribution as well as a power-law decay of the two-point correlation function, in agreement with our theoretical model. Furthermore, the experimental singularity spectrum f($\alpha$) shows anomalous scaling behavior typical from 2D weakly disordered systems

Design principles and architecture of a second language learning chatbot

The purpose of this article is to set out the design principles and architecture of a second language (L2) learning voice chatbot. Building on L2 acquisition theories and chatbot research, in this article, we report on a South Korean government-funded longitudinal project in which we designed and developed a chatbot called “Ellie”. Chatbot Ellie has three chat modes, “General Chat,” “Task Chat,” and “Skills”. In the General Chat mode, L2 users can have short talks about personal information, whereas in the Task Chat mode, they can engage in a wide range of problem-solving L2 tasks to achieve task goals by exchanging meanings with Ellie. The Skills mode offers form-focused language practice. Ellie was piloted among 137 Korean high school students, who used Ellie individually or in a group, for seven weeks in their English classes. The quality of the chatbot was investigated in terms of the appropriateness of language level, continuity of conversation, and success in task performance. Based on the results of the pilot, Ellie appears to have considerable potential to become an effective language learning companion for L2 learners, and has implications for the design and developments of future L2 chatbots