A set of ultrawide bandgap single-crystal NdGaO3 samples cut with crystallographic surface orientations (001), (101), and (110) are investigated by using generalized spectroscopic ellipsometry. We report the complex anisotropic dielectric functions in the spectral range from 0.73 to 9.0 eV, for polarization along directions a, b, and c of the orthorhombic unit cell. A Kramers-Kronig consistent parameterized model was utilized to identify critical point structures and their association with band-to-band transitions, and the results from density functional theory (DFT) calculations for the electronic band structure of NdGaO3 are compared. A Cauchy parameter analysis for the three refractive indices is performed in the below bandgap spectral range. Dielectric functions along lattice directions a, b, and c and their respective bandgap energy values are very similar. Below the bandgap energy, the refractive index differences for directions a and b are very small (0.34% on average) while index differences with direction c (approximately 1.25%) lead to effective positive uniaxial optical properties ( n(c) > n(a) approximate to n(b) ) toward the phonon modes spectral range. Our ellipsometry analysis determines the lowest band-to-band transitions of NdGaO3 to occur at E-a = 6.46 ( 6 ) eV, E-b = 6.29 ( 5 ) eV, and E-c = 6.77 ( 7 ) eV, i.e.,E-c> E-a > E-b, while our DFT calculations predict the first transition to be lowest along the a axis. We discuss our findings in light of previous reports and present all parameters of our theoretical and experimental analyses.
Rather than framing disinformation as false facts which can be countered by true facts, we propose a model of disinformation as narrative by tracing three case studies of successful disinformation across Facebook and Twitter. As stories, disinformation disseminates throughout culture and exists at all levels of media and across genres. Using a dataset of content hosted on URLs shared widely on social media corresponding to U.S. left, right, and nonpartisan examples of disinformation, we examine how successful disinformation circulates as narratives across platforms and genres. We find that all three case studies meet the formal criteria of narrative, and that narrative is intrinsically emotional and moral, providing catharsis for those who share it. Understanding that successful disinformation narratives are enforced by cultural forces, are intrinsically linked to identity, and hold deep emotional resonance for those with whom they resonate has vast implications for responding to and countering them.
The Critical Zone (CZ) evolves through interactions between surface processes and the solid Earth, yet its complexity remains poorly constrained due to sparse subsurface data. Here, we analyse 18 boreholes drilled along the eastern flank of the tropical Western Cordillera to circumvent the limitations from prior studies of weathering profiles, mostly at the scale of hillslopes. The data show that deep (>48 m), multilayered weathering profiles dominate high-elevation ridges and mid-slopes (>1,100 m), while saprolite is absent at lower elevations. The multilayered profile consists of four layers that go from lightly (L4) to moderately (L3) weathered diabase (dark grey to light greenish grey, respectively) up to a reddish yellow to dark reddish saprolite (L1) that overlies a yellow saprolite (L2). Estimates of fracture density (P-10) reveal crushed zones (P-10 > 30 m(-1)) are more abundant toward the western flank of the Western Cordillera. Fracture density also increased toward the surface at shallower levels. Borehole elevation and fracturing both seem to exhibit controls on weathering profile development: at mid to low elevations, we interpret high fracture density as enhancing erosion and inhibiting saprolite formation, whereas at high elevations, fracturing combines with vegetation and moisture to promote deep weathering. Although saprolites are thick at high elevations, water table measurements show a seasonal increase in elevation of the water table, potentially enhanced by high hydraulic conductivity as estimated via packer tests (n = 5) in two boreholes. High conductivity and active percolation of meteoric water at high elevations are further confirmed by oxide/carbonate precipitation below saprolite layers. We propose that long-term exhumation of fractured, conductive layers sustains thick weathering profiles at high elevations, whereas fracturing limits CZ development at lower sites. Notably, fractured mafic rocks develop weathering profiles comparable to granitic systems, underscoring the coupled role of lithology and structure in CZ evolution.
The construction of Christian identity is an ongoing and communicative process, the study of which requires not just 'taking talk seriously', but constitutively. As Christian disaffiliation becomes more common in the United States and forms of Christianity are implicated in violent white nationalism, what it means to be a Christian is being openly contested through language about church. The qualitative research in this study draws on 45 semi-structured interviews with Christian disaffiliates to uncover the discursive assertions they make about what it means to be Christian. A turning-point analysis reveals two commonly narrativized experiences altering these disaffiliates' relationship with church: (1) culture shock, in which disaffiliates encountered new moral frameworks outside the social world of their childhood church and (2) embodied non-normativity, physically maturing into a person whose body does not fit heteropatriarchal church norms. Participants framed these two turning points in ways that discursively assert that Christians create hierarchies of who can be honest at church, premised on patriarchalism and heteronormativity. By taking disaffiliates' narratives as partially constitutive of Christian identity, this study shows how people outside Christianity are shaping what it means to be a Christian in the United States today.
Both multiple-choice (MC) and cued-recall (CR) practice questions are beneficial for learning, but how do students choose to use each format of practice question? Will students’ learning choices indicate they believe each format has non-redundant utility? Across two experiments, I proposed and evaluated hypotheses regarding how students might regulate their use of MC and CR practice questions when they have access to both formats for the same material. Briefly, students might think the two formats are redundant, think the two formats are non-redundant in that both are uniquely beneficial, or think the two formats are non-redundant but that one is better than the other. To assess these hypotheses, some student participants had access to both MC and CR optional practice questions and could complete either or both formats as many times as they wanted. I found support for the non-redundant utility hypothesis. Specifically, most participants preferred completing MC questions and used only this format until they got each question correct about one time. However, about one-third of participants used both MC and CR questions for most material, and continued practice until they got each question correct more than one time with each format. Thus, participants’ learning choices indicated that they believe multiple-choice and cued-recall practice questions have unique utility and provided support for the non-redundant utility hypothesis.
