Search

The second‐law analysis evaluates the irreversibilities of a process. Systematic study of the relationship between thermodynamic efficiency and process modifications enhances process synthesis. The Allam cycle is an oxy‐fuel combustion cycle with nearly complete carbon capture that offers greater efficiency than current electricity generating systems. This study applies lost work analysis to the original Allam cycle and three modifications to obtain the distribution of irreversibilities and the effects of different configurations among potential process improvements for more sustainable power generation. The major inefficiencies are from the combustors and heat exchangers. We also examine the economic profitability of the alternatives. The largest equipment costs are for the turbines, compressors, and recuperators. We find that improving efficiency leads to less economic return; a configuration with partial compression has the highest efficiency, while the original Allam cycle has the highest profitability. We discuss how to resolve this apparent conflict between sustainability and profitability. [ABSTRACT FROM AUTHOR]

Thermodynamics challenges teachers and learners. Its pervasiveness about nature, mathematical abstractness, nonnumerical relations, and complexity in applications can inhibit understanding and usage, especially by undergraduates. Perspectives are given about these obstacles, and some suggestions are made to enhance comprehension of the discipline.

The management of patients with a maxillary tumour is complex, especially reconstruction and rehabilitation. The techniques for closure or obturation of any oro-antral/nasal communication are well described. What is less well described is the effective and timely restoration of facial form and dentition, ideally prior to commencement of radiotherapy. This paper describes the use of the zygomatic implant perforated (ZIP) flap technique to provide immediate reconstruction and rapid dental rehabilitation in three cases of midface/maxillary oncologic ablative defects. Three patients who underwent ZIP flap reconstruction at St James’s Hospital between September 2022 and March 2023 are described. One of them had a total maxillectomy and two had an extended hemi-maxillectomy. All patients had a ZIP flap including a radial forearm free flap, with four zygomatic implants in one case and two zygomatic implants in each of the other cases. All implants placed had good primary stability and the median time to prosthesis fit was 22 days. All patients underwent adjuvant radiotherapy. [ABSTRACT FROM AUTHOR]

Like so many other states, Iowa faces the acute challenge of improving teacher quality. To address this problem, the state has been conducting and procuring a system over the last two years that will move Iowa into compliance with No Child Left Behind Act (NCLB) requirements in the areas of teacher quality and the core subjects of reading, mathematics, and science. Building on experiences and lessons learned from previous state efforts, Iowa is now focusing on teaching pedagogy and best practices in the previously mentioned academic areas, teacher technology support, and the creation of learning communities. Specifically, the state is attempting to: (1) Address the NCLB requirements within the context of the federal government's educational entitlement programs as a rural state; (2) Discuss the problem of evaluating the effectiveness of technology and teacher fidelity in implementing pedagogy in meeting the NCLB requirements; and (3) Develop and evaluate a communication plan and support system in order to disseminate effective strategies and best practices to other schools both within and outside of Iowa. This article discusses the combination of technology and the greater involvement of administrators in changing the previous cycle of ineffectiveness to one that makes a real difference in teaching and learning.

This article is the second of three projected IUPAC Technical Reports on reference materials for phase equilibrium studies. The goal of this project was to select reference systems with critically evaluated property values for the verification of instruments and techniques used in phase equilibrium studies of mixtures. This report proposes seven systems for solid–liquid equilibrium studies, covering the four most common categories of binary mixtures: aqueous systems with organic solutes, aqueous systems with inorganic solutes, non-aqueous systems, and systems with low solubility. For each system, the available literature sources, accepted data, smoothing equations, and estimated uncertainties are given. [ABSTRACT FROM AUTHOR]

The article announces the Annual Meeting of American Institute of Chemical Engineers to be held on November 13, 2022 – November 18, 2022 at Phoenix Convention Center, Phoenix, Arizona.

Mesoscopic simulations using Langevin dipoles on a lattice for the solvent and calculated partial charges for the solute have been used to estimate free energies of adsorption from data on reversed-phase chromatography on nine protected peptides covering a wide range of structures. There is a single parameter, the effective solvent dipole moment, that is fit to data for one peptide and used to predict properties of the other eight peptides. Good agreement of adsorption chemical potentials, including order of chromatographic retention times, is found for calculations that are Boltzmann-averaged over a set of orientations. In addition, the results suggest that there are preferential orientations for each peptide at the model hydrophobic chromatographic surface. Estimation methods for adsorption based on molecular descriptors and hydrophobicity scales are shown to be unreliable for these systems. With refinements and extensions, this simulation method should be applicable to solvents containing salt, such as in hydrophobic interaction chromatography, and to larger solutes including proteins.