Polyurethane rigid foams modeling project

Title from PDF of title page (University of Missouri--Columbia, viewed on September 12, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Galen SuppesIncludes bibliographical references.M.S. University of Missouri-Columbia 2013.Dissertations, Academic -- University of Missouri--Columbia -- Chemical engineering."May 2013"A theoretical model was developed to simulate the polyurethane foaming process for a rigid foam. In the model, multiple ordinary differential equations were solved by MATLAB and the model was able to predict temperature profiles by inputting foam recipe information. This initial study on foam modeling focusses on reaction kinetic parameters that were fitted to experimental temperature data as a function of time. The modeling was able to accurately model temperature profiles of single-polyol polyurethane formulations and was able to accurately predict temperature profiles of mixtures based on pure component kinetic parameters. A primary goal of this work is to expedite the ability to develop new foam formulations by simulation - especially for incorporation of new bio-based polyols into formulations. The MATLAB model was developed further to include the impact of catalyst loading for the reactions. In addition, becoming knowledge on likely fates of unreacted isocyanate and developing experimental plan to evaluate reactions with excess isocyanate in solvents are significant. ASTM isocyanate titration was applied to measure isocyanate content in system during foaming process. Experiments with different amount of catalyst were carried out to verify accuracy of the model

A Multi-Stage Framework for the 2022 Multi-Structure Segmentation for Renal Cancer Treatment

Three-dimensional (3D) kidney parsing on computed tomography angiography (CTA) images is of great clinical significance. Automatic segmentation of kidney, renal tumor, renal vein and renal artery benefits a lot on surgery-based renal cancer treatment. In this paper, we propose a new nnhra-unet network, and use a multi-stage framework which is based on it to segment the multi-structure of kidney and participate in the KiPA2022 challenge

2011 Research Highlights

Overview •Center Mission and Cluster Tasks •Recent Scientific Achievements •Current & Future Development

Simulating large-size quantum spin chains on cloud-based superconducting quantum computers

Quantum computers have the potential to efficiently simulate large-scale quantum systems for which classical approaches are bound to fail. Even though several existing quantum devices now feature total qubit numbers of more than one hundred, their applicability remains plagued by the presence of noise and errors. Thus, the degree to which large quantum systems can successfully be simulated on these devices remains unclear. Here, we report on cloud simulations performed on several of IBM's superconducting quantum computers to simulate ground states of spin chains having a wide range of system sizes up to one hundred and two qubits. We find that the ground-state energies extracted from realizations across different quantum computers and system sizes reach the expected values to within errors that are small (i.e. on the percent level), including the inference of the energy density in the thermodynamic limit from these values. We achieve this accuracy through a combination of physics-motivated variational Ansatzes, and efficient, scalable energy-measurement and error-mitigation protocols, including the use of a reference state in the zero-noise extrapolation. By using a 102-qubit system, we have been able to successfully apply up to 3186 CNOT gates in a single circuit when performing gate-error mitigation. Our accurate, error-mitigated results for random parameters in the Ansatz states suggest that a standalone hybrid quantum-classical variational approach for large-scale XXZ models is feasible.Comment: 21 pages, 12 figures, 4 tables; title change; substantial revisio

Modeling and experimental study of polyurethane foaming reactions

Polyurethanes are very important polymers and are used in a wide range of applications. A theoretical model was developed to simulate polyurethane foaming reactions. In the model, multiple ordinary differential equations were solved by MATLAB program and the model was able to predict temperature, foam height and concentration profiles. This model can provide a better understanding of fundamental polyurethane chemistry and the foaming process. Further modeling and experimental studies were performed to improve accuracy and to expand capability of the simulation program. Impact of side reactions, impact of catalyst and surfactant concentrations and impact of catalysis poisoning were taken into consideration and included in the model. The revised model was able to predict bubble radius, inside bubble pressure, vapor pressure of pure isocyanate as well as more reasonable temperatures, foam height, and concentration profiles. Reaction kinetics and thermodynamics parameters used in the simulation program were verified by experimental and/or computational methods respectively. The use of simulation offers a way to control the complexity and transform materials design, just as process simulators have transformed engineering design. This perspective presents a case that simulation is ready to change the way we research, develop, and design polyurethane formulations

Fluid-present Anatexis of Neoarchean Tonalite and Amphibolite in the Western Shandong Province

Metatonalite and amphibolite from the Taishan region of the Western Shandong Province in the North China Craton record c. 2.60 Ga fluid-present partial melting via the breakdown of biotite, plagioclase and quartz to produce peritectic hornblende and anatectic melt. Eight paired leucosome–melanosome samples from metatonalite and three paired samples from amphibolite were investigated to evaluate the composition of the melt. Hornblende, biotite and plagioclase in the leucosomes and hornblende and plagioclase in melanosomes from both rock types have similar compositions. Two leucosome samples from the metatonalite were influenced by the removal of heavy rare earth element-rich hornblende and the accumulation of plagioclase. The other leucosomes are interpreted to represent near initial melt compositions with a minor component of peritectic hornblende and are enriched in Si, Na and Sr and depleted in K, Ca, Ba and Rb relative to melanosomes. The enrichment of Na in the melt is inconsistent with experimental results of fluid-present melting of tonalite, but is broadly consistent with the experimental results of fluid-fluxed melting of amphibolite. The absence of K-feldspar in both rock types is a critical control on the composition of anatectic melt and initial melt compositions were probably similar for both rock types. Leucosomes inherited rare earth element patterns from their sources, which suggests that some trace element diagrams used to infer tectonic settings and depths of melting are not appropriate for reworked components of Archean grey gneisses. Whole-rock δ18O suggest that the fluids responsible for inducing local melting were derived from the intrusion and crystallization of ~2.60 Ga tonalites and trondhjemites in the Taishan region. One amphibolite sample has a relatively low δ18O suggestive of interaction with meteoric water or seawater possibly related to crustal extension and asthenosphere upwelling at ~2.60 Ga. Fluid-present partial melting reworked 2.75–2.60 Ga tonalites and amphibolites, generating ~2.60 Ga sodium-rich components of grey gneisses in the Western Shandong Province

Antiperovskite Li3OCl Superionic Conductor Films for Solid-State Li-Ion Batteries.

Antiperovskite Li3OCl superionic conductor films are prepared via pulsed laser deposition using a composite target. A significantly enhanced ionic conductivity of 2.0 × 10-4 S cm-1 at room temperature is achieved, and this value is more than two orders of magnitude higher than that of its bulk counterpart. The applicability of Li3OCl as a solid electrolyte for Li-ion batteries is demonstrated