Relevant bibliographies by topics / Enthalpy decomposition

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Academic literature on the topic 'Enthalpy decomposition'

Author: Grafiati
Published: 5 June 2025
Last updated: 8 July 2025

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Journal articles on the topic "Enthalpy decomposition"

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Maitra, S., N. Chakrabarty, and J. Pramanik. "Decomposition kinetics of alkaline earth carbonates by integral approximation method." Cerâmica 54, no. 331 (2008): 268–72. http://dx.doi.org/10.1590/s0366-69132008000300001.

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The decomposition kinetics of four synthetic alkaline earth metal carbonates (MgCO3, CaCO3, SrCO3 and BaCO3) was studied under non-isothermal conditions from thermo-gravimetric measurements as compared to. The integral approximation method of Coats and Redfern was used to determine the kinetic parameters for the decomposition processes. The decomposition reactions followed mostly first order kinetics and the activation energy of the decomposition reactions increased with the increase in the molecular mass of the carbonates. The change in enthalpy for the decomposition processes was also calculated and compared with the activation energies for the decomposition processes. The activation energy of the decomposition process for all the carbonates was higher than the enthalpy of the reaction excepting SrCO3.
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Dunaev, Anatoliy M., Vladimir B. Motalov, Mikhail A. Korobov, Dmitrii Govorov, Victor V. Aleksandriiskii, and Lev S. Kudin. "Vapor Composition and Vaporization Thermodynamics of 1-Ethyl-3-methylimidazolium Hexafluorophosphate Ionic Liquid." AppliedChem 3, no. 2 (2023): 303–19. http://dx.doi.org/10.3390/appliedchem3020019.

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The processes of the sublimation and thermal decomposition of the 1-ethyl-3-methylimidazolium hexafluorophosphate ionic liquid (EMImPF6) were studied by a complex approach including Knudsen effusion mass spectrometry, IR and NMR spectroscopy, and quantum chemical calculations. It was established that the vapor over the liquid phase primarily consists of decomposition products under equilibrium conditions. Otherwise, the neutral ion pairs are the only vapor components under Langmuir conditions. To identify the nature of the decomposition products, an experiment on the distillation of the ionic liquid was performed and the collected distillate was analyzed. It was revealed by the IR and NMR spectroscopy that EMImPF6 decomposes to substituted imidazole-2-ylidene (C6N2H10PF5) and HF. The measured vapor pressure of C6N2H10PF5 reveals a very low activity of the decomposition products (<10−4) in the liquid phase. The absence of a significant accumulation of decomposition products in the condensed phase makes it possible to determine the enthalpy of sublimation of the ionic liquid assuming its unchanged activity. The thermodynamics of the EMImPF6 sublimation was studied by Knudsen effusion mass spectrometry. The formation enthalpy of EMImPF6 in the ideal gas state was found from a combination of the sublimation enthalpy and formation enthalpy of the ionic liquid in the condensed state. The obtained value is in good agreement with those calculated by quantum chemical methods.
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Kirilov, P. P., I. N. Gruncharov, and Y. G. Pelovski. "Enthalpy of thermal decomposition of pyrite concentrate." Thermochimica Acta 244 (October 1994): 79–83. http://dx.doi.org/10.1016/0040-6031(94)80208-4.

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MUSUC, Adina Magdalena, and Dumitru OANCEA. "The structure-activity relationships from DSC data." Revue Roumaine de Chimie 66, no. 2 (2021): 161–66. http://dx.doi.org/10.33224/rrch.2021.66.2.06.

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The differential scanning calorimetry becomes nowadays an easily available technique able to provide experimental data which can be used to seek for possible correlations with molecular properties. Among these data, the entropy and enthalpy for different phase transition like melting or decomposition of various related compounds proved to be very fruitful. In the present paper, the enthalpy and entropy data for different phase transitions and decomposition of two classes of related energetic compounds (13 based on phenoxazone derivatives and 6 on substituted (E)-3-(azulen-1-yldiazenyl)-1,2,5-oxadiazole) are analyzed and presented. The heats of decomposition seem to present no correlations as functions of molecular mass or melting temperature, while the heats of melting and the temperatures of melting present a fair correlation as a function of the molecular mass or melting temperature. A particularly good correlation is provided by the entropy of melting as a function of the enthalpy of melting, in accord with their significance for a process at equilibrium.
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Dubrawski, J. V., and S. St J. Warne. "Differential Scanning Calorimetry of Minerals of the Dolomite-Ferroan-Dolomite-Ankerite Series in Flowing Carbon Dioxide." Mineralogical Magazine 52, no. 368 (1988): 627–35. http://dx.doi.org/10.1180/minmag.1988.052.368.07.

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AbstractThe dolomite-ferroan-dolomite-ankerite series of carbonate minerals has been investigated in flowing carbon dioxide using high-temperature DSC. Decomposition products were analysed by X-ray diffraction. The minerals studied included dolomite containing no iron, and members substituted by iron in the molar ratio range of 0.082 to 0.49. Complete resolution of the three main endothermic features was observed and enthalpy values ΔH, determined from each. The individual and total enthalpy values showed a linear dependence upon the Fe and Mg content of the members across the series. A decrease in the enthalpy of decomposition occurs with increasing Fe content. The effect of Fe substitution was readily observed and the estimated limit of detection is less than 1% FeO. Accuracy of the measurements was limited by the purity of the minerals themselves.
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Mahon, Daniel, Gianfranco Claudio, and Philip Eames. "An Experimental Study of the Decomposition and Carbonation of Magnesium Carbonate for Medium Temperature Thermochemical Energy Storage." Energies 14, no. 5 (2021): 1316. http://dx.doi.org/10.3390/en14051316.

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To improve the energy efficiency of an industrial process thermochemical energy storage (TCES) can be used to store excess or typically wasted thermal energy for utilisation later. Magnesium carbonate (MgCO3) has a turning temperature of 396 °C, a theoretical potential to store 1387 J/g and is low cost (~GBP 400/1000 kg). Research studies that assess MgCO3 for use as a medium temperature TCES material are lacking, and, given its theoretical potential, research to address this is required. Decomposition (charging) tests and carbonation (discharging) tests at a range of different temperatures and pressures, with selected different gases used during the decomposition tests, were conducted to gain a better understanding of the real potential of MgCO3 for medium temperature TCES. The thermal decomposition (charging) of MgCO3 has been investigated using thermal analysis techniques including simultaneous thermogravimetric analysis and differential scanning calorimetry (TGA/DSC), TGA with attached residual gas analyser (RGA) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) (up to 650 °C). TGA, DSC and RGA data have been used to quantify the thermal decomposition enthalpy from each MgCO3.xH2O thermal decomposition step and separate the enthalpy from CO2 decomposition and H2O decomposition. Thermal analysis experiments were conducted at different temperatures and pressures (up to 40 bar) in a CO2 atmosphere to investigate the carbonation (discharging) and reversibility of the decarbonation–carbonation reactions for MgCO3. Experimental results have shown that MgCO3.xH2O has a three-step thermal decomposition, with a total decomposition enthalpy of ~1050 J/g under a nitrogen atmosphere. After normalisation the decomposition enthalpy due to CO2 loss equates to 1030–1054 J/g. A CO2 atmosphere is shown to change the thermal decomposition (charging) of MgCO3.xH2O, requiring a higher final temperature of ~630 °C to complete the decarbonation. The charging input power of MgCO3.xH2O was shown to vary from 4 to 8136 W/kg with different isothermal temperatures. The carbonation (discharging) of MgO was found to be problematic at pressures up to 40 bar in a pure CO2 atmosphere. The experimental results presented show MgCO3 has some characteristics that make it a candidate for thermochemical energy storage (high energy storage potential) and other characteristics that are problematic for its use (slow discharge) under the experimental test conditions. This study provides a comprehensive foundation for future research assessing the feasibility of using MgCO3 as a medium temperature TCES material. Future research to determine conditions that improve the carbonation (discharging) process of MgO is required.
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Zhou, F., Y. T. Chou, and E. J. Lavernia. "Decomposition and thermodynamic property of metastable Fe–Zn solid solutions produced by mechanical alloying." Journal of Materials Research 17, no. 12 (2002): 3230–36. http://dx.doi.org/10.1557/jmr.2002.0467.

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Thermal decomposition of supersaturated single-phase body-centered cubic (bcc) Fe100−xZnx (5≤ x ≤65 at.%) solid solutions, processed via mechanical alloying of high-purity metal powders, was investigated using x-ray diffraction and differential scanning calorimetry (DSC). At elevated temperatures the metastable solid solution decomposed into a stable equilibrium aggregate consisting of the pure bcc Fe phase and an intermetallic compound Fe4Zn9. The decomposition temperature decreased with increasing Zn concentration. The enthalpy of decomposition for various Fe–Zn solid solutions measured by the DSC was in the range of 1.2–3.5 kJ/mol. The enthalpy of mixing of the as-milled solid solutions from elemental Fe and Zn powders was estimated to be 0.5–1.7 kJ/mol. In addition, the activation energies of decomposition for these solid solutions were determined on the basis of the Kissinger analysis, and their values appeared to be independent of the Zn concentration in the alloy, with an average of 147 ± 17 kJ/mol.
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Humphries, Terry D., Motoaki Matsuo, Guanqiao Li, and Shin-ichi Orimo. "Complex transition metal hydrides incorporating ionic hydrogen: thermal decomposition pathway of Na2Mg2FeH8 and Na2Mg2RuH8." Physical Chemistry Chemical Physics 17, no. 12 (2015): 8276–82. http://dx.doi.org/10.1039/c5cp00258c.

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The optimised syntheses of Na<sub>2</sub>Mg<sub>2</sub>FeH<sub>8</sub> and Na<sub>2</sub>Mg<sub>2</sub>RuH<sub>8</sub> are reported and their thermal decomposition pathways established. The enthalpy and entropy of each decomposition step has been determined by PCI measurements.
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Zhang, Yubin, Zhengsong Qiu, Jiaxing Mu, et al. "Intelligent Temperature-Control of Drilling Fluid in Natural Gas Hydrate Formation by Nano-Silica/Modified n-Alkane Microcapsules." Nanomaterials 11, no. 9 (2021): 2370. http://dx.doi.org/10.3390/nano11092370.

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Inhibiting hydrate decomposition due to the friction heat generated by the drilling tools is one of the key factors for drilling hydrate formation. Since the existing method based on chemical inhibition technology can only delay the hydrate decomposition rate, a phase-change microcapsule was introduced in this paper to inhibit, by the intelligent control of the drilling fluid temperature, the decomposition of the formation hydrate, which was microencapsulated by modified n-alkane as the core material, and nano-silica was taken as the shell material. Scanning electron microscope (SEM), size distribution, X-ray diffraction (XRD), and Fourier transform infrared spectrometer (FT-IR) were utilized to characterize the structural properties of microcapsules. Differential scanning calorimetry (DSC) spectra displayed that the latent heat was 136.8 J/g in the case of melting enthalpy and 136.4 J/g in the case of solidification enthalpy, with an encapsulation efficiency of 62.6%. In addition, the prepared microcapsules also showed good thermal conductivity and reliability. By comparison, it was also proved that the microcapsules had good compatibility with drilling fluid, which can effectively control the temperature of drilling fluid for the inhibition of hydrate decomposition.
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Kiselev, Vitaly G. "Comment on “Decomposition mechanisms of trinitroalkyl compounds: a theoretical study from aliphatic to aromatic nitro compounds” by G. Fayet, P. Rotureau, B. Minisini, Phys. Chem. Chem. Phys., 2014, 16, 6614." Physical Chemistry Chemical Physics 17, no. 15 (2015): 10283–84. http://dx.doi.org/10.1039/c4cp04999c.

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The approach proposed in the original paper yields spurious contributions to both enthalpy and entropy of activation of barrierless reactions. This renders reaction branching ratios intrinsically biased towards radical decomposition of nitro species.
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Book chapters on the topic "Enthalpy decomposition"

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"Decomposition Conditions and the Molar Enthalpy." In Hot Topics in Thermal Analysis and Calorimetry. Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-5672-7_5.

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Binda, Ricardo Viera, Roberta Jachura Rocha, and Luiz Eduardo Nunes Almeida. "Study of Factors Influencing the Life Predictions of Solid Rocket Motor." In Energetic Materials Research, Applications, and New Technologies. IGI Global, 2018. http://dx.doi.org/10.4018/978-1-5225-2903-3.ch011.

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Storage of rocket motors loaded with composite solid propellant for long periods may change the propellant properties, thus causing failure and affecting the safety during launch. In this study, an accelerated aging assay was carried out, in order to predict the useful lifetime and to evaluate variations on the propellant properties with time by means of thermal analysis (TG/DSC). The aging temperatures used were 65°C, and samples were withdrawn after 3 months. Aging was also carried out at room temperature. There was significant variation in the activation energy of the solid propellant samples thermal decomposition in the two kinetic methods used – Ozawa or model-free isoconversional method and Kissinger method – during the aging period. There was significant decrease of enthalpy of aged propellant enthalpy causing changes in ballistics parameters of the solid propellant grain affecting the rocket's performance.
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Timushev, Sergey, Andrey Aksenov, and Jiawen Li. "Acoustic-Vortex Decomposition Method for CFD-CAA Study of Blade Machine Noise." In Vortex Dynamics - Theoretical, Experimental and Numerical Approaches [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1006111.

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This chapter presents a method for calculating the generation of pressure pulsations and noise emission by blade machines based on the decomposition of the compressible medium velocity field into vortex and acoustic modes. This method of acoustic-vortex decomposition of the basic equations of motion of a compressible medium leads to an inhomogeneous wave equation with respect to enthalpy pulsations, which includes pseudo-sonic oscillations in the source vortex region and acoustic oscillations in the near-field and far-field. The source function in the wave equation is determined from the independent solution of the vortex mode equations. The boundary conditions for the wave equation are formulated using complex specific acoustic impedance and pseudo-sonic oscillations. This method allows for the consideration of the influence of inhomogeneity and turbulence of the flow, rotor interference, sound diffraction on the elements of the flow part, and impedance characteristics of the machine surfaces, while ensuring the accuracy and speed of calculations. The acoustic-vortex method represents the noise source as a function of the vortex mode velocity field. This approach eliminates the arbitrariness and conventionality of the aeroacoustic analogy, defining the source, pressure pulsations, and noise propagation in the near-field as a direct result of numerical modelling.
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Gokul Raj, S. "Thermogravimetric & Differential Thermal Analysis (TG-DTA)." In CHARACTERIZATION OF SINGLE CRYSTALS. Royal Book Publishing, 2025. https://doi.org/10.26524/225.11.

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Thermal analysis (TA) involves measuring specific physical and chemical properties as a function of temperature. These properties primarily include enthalpy, heat capacity, mass, and the coefficient of thermal expansion. A simple example of thermal analysis (TA) is determining the coefficient of thermal expansion in metal bars. Another example is measuring the weight changes of oxysalts or hydrates as they decompose under heat. TA has a wide range of applications in solid-state science, including the study of solid-state reactions, thermal decompositions, phase transitions, and the construction of phase diagrams. Most solids exhibit some form of thermal activity, making them suitable for investigation through TA. The primary TA techniques are thermogravimetry (TGA) and differential thermal
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Conference papers on the topic "Enthalpy decomposition"

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Hadzidakis, M., F. Karagiannis, P. Chaviaropoulos, and K. D. Papailiou. "Unsteady Euler Calculations in 2-D Internal Aerodynamics With Introduced Vorticity." In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-168.

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This paper presents an implicit finite difference algorithm which solves the unsteady Euler equations in two-dimensional ducts. The unsteady nature of the flow is due to the time dependent inflow and outflow boundary conditions, while the geometry does not change in time. The present work is based on the Helmholtz decomposition of the unsteady velocity field into a potential and a rotational part. Vorticity is introduced at the inlet by means of velocity, total enthalpy or even entropy slope. The presented results cover a wide range of reduced frequencies in the subsonic regime.
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Nakatsuka, Noriaki, Yasushi Imoto, Jun Hayashi, et al. "Decomposition of Toluene as a Biomass Tar Through Partial Combustion." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44159.

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For the electric power generation by the woody biomass gasification, tar is incidentally formed at the same time. Tar means a compound of many kinds of aromatic hydrocarbons and causes some troubles, for example, clogging pipes when it is cooled and condensed before being supplied to the gas engine for electric power generation. One way for reducing tar is oxidative and thermal cracking by partial combustion of the producer gas in the gas reformer that is a stage subsequent to the biomass gasifier. During the partial combustion process of the producer gas, inverse diffusion flame is formed when oxidizer is supplied to producer gas. Cracking and polymerization of tar occur simultaneously at the proximity of the inverse diffusion flame. This polymerization of tar into soot is, however, a significant problem in the gas reformer. Experimental study was performed to clarify the effect of hydrogen concentration in the combustion region on soot formation and the growth of polycyclic aromatic hydrocarbons (PAHs) that is precursor of soot. In the present study, hydrogen concentration at the proximity of the inverse diffusion flame was controlled by the small amount of hydrogen addition to the oxidizer. The main results were as follows. Soot formation was suppressed by the small amount of hydrogen addition (approximately 0.5% to the total enthalpy of the producer gas). The suppression of soot formation was caused by higher concentration of hydrogen at the proximity of the combustion region since the aromatic radicals were neutralized before they could combine together or with acetylene. Carbon yield was increased with the increase in the amount of hydrogen added to the oxidizer as carbon content in the undetectable components by the integrated gas chromatograph such as the soot was decreased. In addition, the increase of carbon yield resulted mainly from the increase in carbon monoxide stemmed from reforming of high-boiling components such as soot.
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Sadangi, R. K., V. Shukla, and B. H. Kear. "Shrouded Plasma Processing of Solution Precursors." In ITSC2006, edited by B. R. Marple, M. M. Hyland, Y. C. Lau, R. S. Lima, and J. Voyer. ASM International, 2006. http://dx.doi.org/10.31399/asm.cp.itsc2006p0911.

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Abstract A shrouded-plasma spray process is described for the production of a metastable powder, deposit or preform. A high enthalpy atmospheric DC arc-plasma torch is used as heat source and a solution precursor as feed material. An aerosol-or liquid-jet of solution precursor is delivered to a steady-state reaction zone within the shrouded-plasma flame, where rapid and controlled precursor decomposition occurs. Depending on the operating conditions, the precursor material is pyrolyzed, melted or vaporized, prior to quenching to form a metastable nano-sized powder. This method is capable of processing a host of metastable materials, including the difficult-to-process refractory metals, oxide and non-oxide ceramics, as well as their composites. In this paper, we will discuss our results on multi-component oxide systems.
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D’Aniello, Raffaele, Simon Gövert, Bertram Janus, and Karsten Knobloch. "Thermoacoustic Characterization of a Swirl Premixed Flame Using Doak’s Momentum Potential Theory." In ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/gt2023-102831.

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Abstract This study proposes a novel approach, based on Doak’s Momentum Potential Theory, for the characterization of the thermoacoustic behavior of turbulent premixed flames. The novel approach has the following two advantages: firstly, an unambiguously separation of acoustic, thermal and turbulent dynamics is achieved by means of a Helmholtz decomposition of the momentum fluctuations density; secondly, the development as well as the interaction between the different dynamics are related to the fluxes of turbulent, acoustic, and thermal mean energies, which can be identified in the fluctuating stagnation enthalpy. The Momentum Potential Theory is applied here for the first time to describe the thermoacoustic behaviour of a confined turbulent flame, represented by large-eddy simulation data of a premixed CH4/Air model combustor. Interaction and energy exchange mechanisms between the fluctuations are analyzed in order to show the potential of the theory as a general framework for the characterization of thermoacoustic problems.
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Utturkar, Yogen, Siddharth Thakur, and Wei Shyy. "Accurate Time-Dependent Computations and Reduced-Order Modeling for Multiphase Flows." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56236.

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In the present study, we initiate development of a non-iterative multiphase algorithm by enhancing the Pressure Implicit with Splitting of Operators (PISO) algorithm. The Gallium fusion problem, which is characterized by a solid-liquid phase front and natural convection effects, is employed as a test case for validation. The problem poses serious computational issues in form of a non-linear energy equation and a strong pressure-velocity-temperature coupling. The single-fluid modeling approach is adopted in conjunction with the enthalpy-based formulation for the temperature equation. The current algorithm computes the solution through a series of predictor-corrector steps with special treatment to achieve rapid convergence of the energy equation. The algorithm demonstrates an enhanced performance for the highly unsteady, chosen test problem. A reduced-order analysis of the simulated data is also performed by Proper Orthogonal Decomposition (POD). Specifically, impact of the constantly changing flow domain, and flow scales, on the POD implementation is highlighted.
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Tesar, Tomas, Radek Musalek, Frantisek Lukac, and Jonas Dudik. "Novel Approach to Deposit Thermally Sensitive Materials Using Hybrid Plasma Spraying." In ITSC 2023. ASM International, 2023. http://dx.doi.org/10.31399/asm.cp.itsc2023p0351.

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Abstract Hybrid plasma spraying has been proved to provide novel coating microstructures as a result of the simultaneous injection of a dry coarse powder and a liquid feedstock into the plasma jet. Such microstructure contains both large splats originating from the conventional dry powder and finely dispersed miniature splats deposited from the liquid. This approach enables preparation of coatings from virtually all materials which are conventionally processed using plasma spraying. However, incorporation of materials susceptible to decomposition at high temperatures is still challenging even using this concept due to the high thermal energy provided to all feedstocks to be deposited. Hereby, we propose an innovative approach of incorporation of thermally-sensitive materials into a coating sprayed using a high-enthalpy plasma torch. As a case study, Al2O3 was sprayed from dry coarse powder and MoS2 was sprayed from the suspension which was deposited directly onto the substrates, i.e., by-passing the hot plasma jet. The retention of the added material in the coating was evaluated using scanning electron microscopy and X-ray diffraction.
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Nokhosteen, Arman, and Sarvenaz Sobhansarbandi. "A Novel Computationally Efficient Numerical Model for Thermal Behavior Prediction of an Evacuated Tube Solar Collector Incorporated With Phase Change Materials: A Preliminary Analysis." In ASME 2022 Power Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/power2022-86324.

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Abstract Phase change materials have been applied as a viable solution for augmenting the thermal behavior of various solar thermal systems, including heat pipe evacuated tube solar collectors. Due to complex heat transfer processes that need to be resolved, performing numerical simulations on these devices is computationally intensive. In this study, a novel hybrid method is introduced where a snapshot based proper orthogonal decomposition method is utilized to develop a reduced order model of the collector/phase change material assembly. The model allows for prediction of the collector’s thermal behavior during day/night time operation, in addition to highlighting the benefits of utilizing phase change materials compared to regular collector, working under similar operating conditions. An enthalpy-based lattice Boltzmann method is utilized for obtaining the snapshot data needed for constructing the reduced order model. The novelties of this hybrid method include reduced computation time, by several orders of magnitude, compared to direct numerical simulation methods and a significant reduction in dependency on meteorological and weather data. Finally, two case studies are considered to examine the accuracy of the model and it’s subsequent industrial applications are discussed.
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Diévart, Pascal, Jing Gong, and Yiguang Ju. "A Comparative Study of the Kinetics of Ethyl and Methyl Esters in Diffusion Flame Extinction." In ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ht2013-17086.

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The rapid growth of eco-friendly biomass derived fuels in transportation requires a fundamental understanding of the uniqueness of their oxidation and combustion characteristics. This paper focuses on one specific class of biofuels, namely Fatty Acids Ethyl Esters (FAEE). A counterflow configuration was employed to measure the extinction limits of the diffusion flames of four ethyl esters (ethyl-butanoate, pentanoate, heptanoate, and nonanoate). The results were compared to that of methyl esters (Diévart et al., 2012, Proceedings of the Combustion Institute, 34). It was observed that both methyl esters and ethyl esters exhibit similar high temperature reactivity against extinction. The use of the transport-weighted enthalpy metric has revealed that all esters share similar chemical kinetics in the near extinction conditions of the present study. A previous detailed kinetic model has been extended to include the oxidation chemistry of ethyl esters, and used to interpret the experimental observations. Good agreement between the computed and experimental extinction limits was observed. The rates of consumption pathway analysis have shown that ethyl esters exclusively decomposed into ethylene and a carboxylic acid through an endothermic six-centered unimolecular decomposition reaction, while methyl esters oxidation preferentially progresses through H abstraction reactions. However, the growth of the radical pool was observed to be driven indifferently between ethyl and methyl esters, therefore resulting in similar global flame reactivity.
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Choi, Jongwun, Hosung Byun, Hyunseung Rhee, Seonwoong Kim, Youchan Park, and Hyungrok Do. "Measurement of flame properties using Laser-induced breakdown spectroscopy at elevated pressures." In GPPS Chania24. GPPS, 2024. http://dx.doi.org/10.33737/gpps24-tc-164.

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To the best of our knowledge, we employ laser-induced breakdown spectroscopy (LIBS) to simultaneously measure multiple properties (pressure, equivalence ratio, and H2 ratio) of product gas under turbulent flow and highenthalpy conditions for the first time. We also introduce an improved LIBS signal acquisition configuration that enhances signal-to-noise ratio (SNR) and shot-to-shot stability. Under varying operating conditions (pressure: 3 to 15 bar, equivalence ratio: 0.7 to 1.2 and hydrogen enriched ratio: up to 50% by volume), the laser is focused at downstream of the multi-nozzle burner where combustion product gas flows turbulently. Laser-induced plasma (LIP) is generated and plasma spectra are simultaneously measured in both right-angle and backward directions. The Proper Orthogonal Decomposition (POD) and Gaussian Process Regression (GPR) model are employed to estimate multiple properties of product gas that exhibit non-linear correlations. POD extracts the principal features from the spectra and GPR model quantifies these properties. The results demonstrate that the proposed model achieves the highest prediction accuracy for pressure, hydrogen concentration, and equivalence ratio, with the average relative errors of model prediction (REP) values of 0.93%, 8.3%, and 1.45%, respectively. Furthermore, measurement in the backward direction yields a more stable and stronger signal intensity compared to those in the right-angle direction measurement. Specifically, the former successfully captures plasma spectra at 15 bar, whereas the latter fails to do so. This study significantly contributes to the precise measurement of combustion product gas in harsh high-enthalpy environments. Our approach provides important information for the design and optimization of combustion-related facilities and indicates promising applicability of LIBS in various other environments.
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Hossain, Mohammad K., Samira N. Shaily, Hadiya J. Harrigan, and Terrie Mickens. "Fabrication and Characterization of Bio-Based Poly Lactic Acid/Polyhydroxybutyrate-Valerate (PLA/PHBV) Blend With Nanoclay." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-67813.

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The objective of this research is to prepare a hybrid biopolymer blend using PLA and PHBV with enhanced mechanical and thermal properties. Bio-based PLA and PHBV blends were prepared using the melt-mixing procedure. Tensile, FTIR, DSC, TGA, optical microscopy (OM), and scanning electron microscopy (SEM) tests were performed to investigate mechanical properties, bonding interaction, glass transition temperature, melting and crystalline enthalpy, thermal decomposition, and morphological analysis. Different percent (1, 2, and 3 wt%) of nanoclay was added to the system to observe the bonding interaction. It was observed that the crystallinity increases with increasing amount of nanoclay. The result showed that the tensile strength of PLA thin film and PHBV film was found to be 31.1 MPa and 14.41 MPa, respectively. Hence, PLA has better mechanical property than PHBV. On the other hand, thermal property of PHBV thin film was found to be better than that of PLA. To optimize both mechanical and thermal properties of PLA and PHBV hybrid biopolymer blend, using various combinations of PLA/PHBV including 25/75, 50/50 and 75/25 wt% a hybrid biopolymer blend was prepared. Among them, PLA-PHBV (75/25 wt%) with 2 wt% nanoclay resulted in the best outcome. The tensile strength of this prepared polymer blend was 29.34 MPa. Thermal analysis demonstrated two melting temperatures: 238.37 °C and 308.31 °C, respectively. Two glass transition temperatures were found from thermal tests which are the indication of the solution immiscibility. It had also been observed that the adding of nanoclay enhances tensile properties as well as thermal stability up to 2 wt%. It is revealed from the optical and SEM micrographs that the 2 wt% NC was dispersed uniformly throughout the resin blend.
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