Thermochemistry of the Aluminas and Aluminum Trihalides

Consistent standard free energies of formation of gibbsite, bayerite, boehmite, and diaspore; their respective transition aluminas, α-Al₂O₃; and AlF₃, AlCl₃, H₂O₃ HF, and HCl are compiled from 298.16 to 2100 K from literature review, computations, and estimates. Significant adjustments and additions to earlier compilations are included. Revised analysis is made of the gibbsite-to-α-A1₂O₃ transition series and of reactions of appropriate aluminas with HF and HCl, comparing them with experimental data. These updated Δ G ° tables should also yield accurate ΔG° data for many other alumina reactions, e.g. with SiO₂, M₂O, MO, etc.     

Reaction of Fused Silica With Hydrogen Gas

Fused silica and flowing hydrogen gas react in the experimental temperature range of 1200° to 1400°C to form SiO and H₂O vapors. Above a critical flow rate of hydrogen gas, the reaction rate is independent of gas flow rate and is not transport-controlled. The apparent activation energy for the overall process was 343±33 kj /mol (82±8 kcal/mol). The rate-limiting step is deduced to be desorption of the product from the glass surface.     

Philanthropic Architecture: Nongovernmental Development Projects in Latin America

In this essay we address the issue of poverty in Latin America and attempt to explain why this region of the world is so desperately poor despite its tremendous natural resources, indigenous skills, and proximity to the United States. We argue that a philanthropic architectural response is required in Latin America that stresses the importance of client/user design education and a respect for indigenous cultures. We describe the work of two NGOs, report on two grass roots projects, and describe how collaboration between Western university architecture departments and local NGOs can involve the community in successful building projects.     

Toward deep impacts of BIM on education

Building information models (BIM) provide a way to represent buildings and communicate about them. In teaching engineering, we also need representations of buildings and are communicating knowledge about them. While teaching engineering we refer to the very same real-world objects that have an explicit conceptualization in BIM. This explicit conceptualization did not exist in the age when design communication relied on drawings and documents. The question that this paper asks is this: due to BIM, communication in the industry has changed. Should communication of engineering knowledge – teaching – change as well and how? While much has been written about teaching BIM and incorporating BIM into the curricula, this paper is exploring the general impact of BIM on engineering education. It grounds earlier work (Turk, 2018) on insights from pedagogy. Five scenarios of the interplay between BIM-influenced engineering communication and teaching are presented. The paper argues that ignoring BIM may create a cognitive dissonance between academic learning and industrial work. We are finding that the impact of BIM is twofold: vertically there is a need to establish a reference between knowledge concepts (in teaching building) and information objects (in building information models). Horizontally BIM is an integration technology that allows for a more holistic design and planning. Both the language of individual courses as well as cross references and synergies among courses should change. A “T” style structure of the courses around BIM is proposed as a basis for integrated curriculum. Pedagogical approaches based on deep learning, model based learning and project based learning are suggested.     

Adaptive forecasting techniques

The class of exponential smoothing models which vary the values of their parameters to adapt to changing conditions in a time series are referred to as adaptive forecasting techniques. In this article criteria for evaluating forecasting models are presented and the features of a simple exponential smoothing model that are exploited by the adaptive techniques are discussed. Several adaptive forecasting schemes are described and classified, and examples of the performance of these techniques are presented.     

Entanglement of orbital angular momentum for the signal and idler beams in parametric down-conversion

We calculate the anticipated correlation between measurements of the orbital angular momentum of the signal and idler beams for parametric down-conversion. These calculations apply to the experiments where the orbital angular momentum state is measured by the use of computer-generated holograms. Displacement of these holograms with respect to the beam axis allows the measurement of superpositions of Laguerre—Gaussian modes. The correlations between such superposition modes of the signal and idler beams show their entanglement and could be used for Bell-type tests of nonlocality.