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UNT Scholarly Works
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Rediscovery of the Elements
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Re-examination of the N2O+O reaction
This article is about how the reaction of N20 with O is a key step in consumption of nitrous oxide in thermal processes. In the present work ,the authors re-examined a wide range of experiments relevant for the N2O+O reaction through kinetic modeling, paying attention to the impact of artifacts such as impurities and surface reactions.
Date:
July 27, 2023
Creator:
Glarborg, Peter; Allingham, Johanne S.; Skov, Alexander B.; Hashemi, Hamid & Marshall, Paul
Object Type:
Article
System:
The UNT Digital Library
Reactions of hydrazine with the amidogen radical and atomic hydrogen
Article describes how the rate coefficient k1 for NH2 + N2H4 was measured to be (5.4 ± 0.4) × 10−14 cm3 molecule−1 s−1 at 296 K. The authors then describe how a combination of experiment and theory leads to a recommended rate coefficient for hydrogen abstraction of k1 = 6.3 × 10−23 T3.44 exp(+289 K/T) cm3 molecule−1 s−1.
Date:
June 7, 2023
Creator:
Gao, Yide; Alecu, I. M.; Hashemi, Hamid; Glarborg, Peter & Marshall, Paul
Object Type:
Article
System:
The UNT Digital Library
Probing High-Temperature Amine Chemistry: Is the Reaction NH3 + NH2 ⇄ N2H3 + H2 Important?
Article describes how the reaction NH3 + NH2 ⇄ N2H3 + H2 (R1) has been identified as a key step to explain experimental results for pyrolysis and oxidation of ammonia. In the present work, the reaction was studied by ab initio theory and by reinterpretation of experimental data.
Date:
March 14, 2023
Creator:
Marshall, Paul & Glarborg, Peter
Object Type:
Article
System:
The UNT Digital Library
Measurement of the Intramolecular Hydrogen-Shift Rate Coefficient for the CH3SCH2OO Radical Between 314 and 433 K
Article describes how the intramolecular hydrogen-shift rate coefficient of the CH3SCH2O2 (methylthiomethylperoxy, MSP) radical, a product formed in the oxidation of dimethyl sulfide (DMS), was measured using a pulsed laser photolysis flow tube reactor coupled to a high-resolution time-of-flight chemical ionization mass spectrometer that measured the formation of the DMS degradation end product HOOCH2SCHO. Measurements performed over the temperature range of 314–433 K yielded a hydrogen-shift rate coefficient of k1(T) = (2.39 ± 0.7) × 109 exp(−(7278 ± 99)/T) s–1 Arrhenius expression and a value extrapolated to 298 K of 0.06 s–1.
Date:
March 2, 2023
Creator:
Assaf, Emmanuel; Finewax, Zachary; Marshall, Paul; Veres, Patrick R.; Neuman, Andrew & Burkholder, James B. (James Bart), 1954-
Object Type:
Article
System:
The UNT Digital Library
Re-evaluation of rate constants for the reaction N2H4 (+ M) ⇄ NH2 + NH2 (+ M)
Article describes how rate constants for the dissociation/recombination reaction N2H4 (+ M) ⇄ NH2 + NH2 (+ M) are determined by a combination of quantum-chemical calculations and statistical unimolecular rate theory. Implications of the present re-evaluated rate constants for the modeling of high temperature ammonia oxidation kinetics are discussed, showing an only small influence of their precise values on the overall properties of the process.
Date:
October 4, 2023
Creator:
Cobos, Carlos J.; Glarborg, Peter; Marshall, Paul & Troe, Jürgen
Object Type:
Article
System:
The UNT Digital Library
Experimental and Modeling Study of Water Time Histories during H2S-N2O Combustion in a Shock Tube
Article describes how, in the present study, the water formation was followed by laser absorption with N2O as an oxidant, instead of O2. Three H2S/N2O mixtures diluted in 98% Ar were studied to cover the following range of equivalence ratios: 0.5, 1.0, and 2.0, over a wide range of temperatures (1580–1940 K) around atmospheric pressure.
Date:
June 7, 2023
Creator:
Cooper, Sean P.; Marshall, Paul; Mathieu, Olivier; Pinzón, Laura T.; Mulvihill, Clayton R. & Glarborg, Peter
Object Type:
Article
System:
The UNT Digital Library
Computational study of the gas-phase reactions of sulfuric acid with OH(ΠJ), O(3PJ), Cl(2P) and O(1D2) radicals
This article is about how rate coefficients for reactions of H2SO4 with OH, O(3P) and Cl radicals over 160–298 K were estimated computationally. The authors propose kOH = 8.5 × 10-14 exp(-50 K/T), kO = 1.1 × 10-12 exp(-5012 K/T) and kCl = 3.1 × 10-9 exp(-3314 K/T) cm3 molecule-1 s−1.
Date:
December 27, 2021
Creator:
Marshall, Paul & Burkholder, James B. (James Bart), 1954-
Object Type:
Article
System:
The UNT Digital Library
An experimental and modeling study on auto-ignition kinetics of ammonia/methanol mixtures at intermediate temperature and high pressure
Article describes how a rapid compression machine has been applied to measure the ignition delay times of NH3/CH3OH mixtures covering pressures of 20 and 40 bar, equivalence ratios of 0.5, 1.0 and 2.0, and temperatures between 845 and 1100 K. Analysis of the pressure profiles shows three distinct ignition modes for NH3/CH3OH mixtures, facilitated by the pre-ignition heat release from NH3 consumption. A detailed mechanism for ignition of NH3/CH3OH fuel blends has been developed, capable of reproducing the ignition behavior of mixtures with reasonable accuracy.
Date:
April 29, 2022
Creator:
Li, Mengdi; He, Xiaoyu; Hashemi, Hamid; Glarborg, Peter; Lowe, Vincent M.; Marshall, Paul et al.
Object Type:
Article
System:
The UNT Digital Library
Comment on ‘Extremely rapid self-reactions of hydrochlorofluoromethanes and hydrochlorofluoroethanes and implications in destruction of ozone’
Article comments on the claims made by the authors of the original article. The authors of the commentary note flaws in the DFT-based methodology and the commentators describe differences between their application and the original article's described application.
Date:
May 26, 2022
Creator:
Marshall, Paul & Burkholder, James B. (James Bart), 1954-
Object Type:
Article
System:
The UNT Digital Library
CAS: Highly Interacting Panchromatic Push-Pull Systems: Symmetry Breaking and Quantum Coherence in Electron Transfer
Data management plan for the grant, "CAS: Highly Interacting Panchromatic Push-Pull Systems: Symmetry Breaking and Quantum Coherence in Electron Transfer."
Date:
2024-04-01/2027-03-31
Creator:
Wang, Hong
Object Type:
Text
System:
The UNT Digital Library
Shared metadata for data-centric materials science
Article describes how the expansive production of data in materials science, their widespread sharing and repurposing requires educated support and stewardship. The authors mainly focus on computational materials-science data and propose a constructive approach for the FAIRification of the (meta)data related to ground-state and excited-states calculations, potential-energy sampling, and generalized workflows.
Date:
September 14, 2023
Creator:
Ghiringhelli, Luca M.; Baldauf, Carsten; Bereau, Tristan; Brockhauser, Sandor; Carbogno, Chistian; Chamanara, Javad et al.
Object Type:
Article
System:
The UNT Digital Library
A general large-scale synthesis approach for crystalline porous materials
Article describes how crystalline porous materials such as covalent organic frameworks (COFs) metal-organic frameworks (MOFs) and porous organic changes (POCs) have been widely applied in various fields with outstanding performances. In this work, the authors developed a general approach comprising high pressure homogenization (HPH), which can realize large-scale synthesis of crystalline porous materials including COFs, MOFs, and POCs under benign conditions.
Date:
November 2, 2023
Creator:
Liu, Xiongli; Wang, An; Wang, Chunping; Li, Jinli; Zhang, Zhiyuan; Al-Enizi, Abdullah M. et al.
Object Type:
Article
System:
The UNT Digital Library
Symmetry breaking charge transfer leading to charge separation in a far-red absorbing bisstyryl-BODIPY dimer
Article describes how symmetry breaking charge transfer is one of the important photo-events occurring in photosynthetic reaction centers that is responsible for initiating electron transfer leading to a long-lived charge-separated state and has been successfully employed in light-to-electricity converting optoelectronic devices. In this study, the authors report a newly synthesized, far-red absorbing and emitting BODIPY-dimer to undergo symmetry-breaking charge transfer leading to charge-separated states of appreciable lifetimes in polar solvents.
Date:
December 15, 2023
Creator:
Yahagh, Aida; Kaswan, Ram R.; Kazemi, Shahrzad; Karr, Paul A. & D'Souza, Francis
Object Type:
Article
System:
The UNT Digital Library
Enhanced Corrosion Resistance and Surface Wettability of PVDF/ZnO and PVDF/TiO2 Composite Coatings: A Comparative Study
Article describes how this study aims to enhance the practical performance of PVDF/ZnO and PVDF/TiO2 composite coatings known for their distinctive properties. The coatings, applied through spray coating with PVDF and ZnO or TiO2 nanoparticles on glass, steel, and aluminum substrates, underwent a comprehensive evaluation.
Date:
October 4, 2023
Creator:
Mohamed, Adel M. A.; Alateyah, Abdulrahman I.; Hasan, Hosam; Matli, Penchal Reddy; El-Sayed Seleman, Mohamed M.; Ahmed, Essam et al.
Object Type:
Article
System:
The UNT Digital Library
A Novel ppb-Level Sensitive and Highly Selective Europium-Based Diketone Luminescent Sensor for the Quantitative Detection of Aluminum Ions in Water Samples
Article describes how a novel Eu(tta)3([4,4′-(t-bu)2-2,2′-bpy)] complex (tta-thenoyltrifluoroacetone), a ratiometric luminescent-based optical sensor for the quantitative determination of aluminum ion, is synthesized and characterized using XRD and 1H NMR. The sensor reported here is tested for 11 common cations and shows no interference on sensitivity. According to the authors, this is the first known Eu-based luminescence sensor that successfully exhibited the ability to detect aluminum ions in ppb levels in aqueous environments.
Date:
November 6, 2023
Creator:
Rajitha Perera, Nawagamu A. K.; Shankar, Sindhu K.; Archambault, Cynthia M.; Nesterov, Vladimir N.; Marpu, Sreekar; Yan, Hao et al.
Object Type:
Article
System:
The UNT Digital Library
Functional Carbon Capsules Supporting Ruthenium Nanoclusters for Efficient Electrocatalytic 99TcO4-/ReO4 Removal from Acidic and Alkaline Nuclear Wastes
Article describes how the selective removal of the β-emitting pertechnetate ion (99TcO4−) from nuclear waste streams is technically challenging. In this article, a practical approach is proposed for the selective removal of 99TcO4− (or its surrogate ReO4−) under extreme conditions of high acidity, alkalinity, ionic strength, and radiation field.
Date:
September 10, 2023
Creator:
Liu, Xiaolu; Xie, Yinghui; Li, Yang; Hao, Mengjie; Chen, Zhongshan; Yang, Hui et al.
Object Type:
Article
System:
The UNT Digital Library
Improving the Selectivity of the C-C Coupled Product Electrosynthesis by Using Molecularly Imprinted Polymer-An Enhanced Route from Phenol to Biphenol
Authors of the article describe how they developed a procedure for selective 2,4-dimethylphenol, DMPh, direct electro-oxidation to 3,3' ,5,5'-tetramethyl-2,2'-biphenol, TMBh, a C-C coupled product. The authors claim that the procedure is reasonably selective towards TMBh without requiring harmful additives or elevated temperatures.
Date:
October 12, 2023
Creator:
Sudagar, Alcina Johnson; Shao, Shuai; Żołek, Teresa; Maciejewska, Dorota; Asztemborska, Monika; Cieplak, Maciej et al.
Object Type:
Article
System:
The UNT Digital Library
Temperature dependent rate coefficients for the gas-phase OH + Furan-2,5-dione (C4H2O3, maleic anhydride) reaction
Authors of the article assert that rate coefficients, k1(T), for the gas-phase reaction of the OH radical with Furan-2,5-dione (maleic anhydride (MA), C4H2O3), a biomass burning related compound, were measured under pseudo first-order conditions in OH using the pulsed laser photolysis - laser induced fluorescence method over a range of temperature and bath gas pressure. Their results are compared with a previous room temperature relative rate study of the OH + MA reaction and significant discrepancy between the studies is discussed. This is the accepted manuscript version of the published article.
Date:
May 30, 2020
Creator:
Chattopadhyay, Aparajeo; Papadimitriou, Vassileios C.; Marshall, Paul & Burkholder, James B. (James Bart), 1954-
Object Type:
Article
System:
The UNT Digital Library
Ignition delay times of NH3/DME blends at high pressure and low DME fraction: RCM experiments and simulations
Authors of the article describe how autoignition delay times of ammonia/dimethyl ether (NH3/DME) mixtures were measured in a rapid compression machine with DME fractions of 0, 2 and 5 and 100% in the fuel. Analysis of the mechanism indicates that this 'early DME oxidation' generates reactive species that initiate the oxidation of ammonia, which in turn begins heat release that raises the temperature and accelerates the oxidation process towards ignition. This is the accepted manuscript version of the published article.
Date:
January 14, 2021
Creator:
Dai, Liming; Glarborg, Peter; Gersen, Sander; Marshall, Paul; Mokhov, Anatoli & Levinsky, Howard
Object Type:
Article
System:
The UNT Digital Library
Oxidation of methylamine
Article describes how a detailed chemical kinetic model for oxidation of methylamine has been developed, based on theoretical work and a critical evaluation of data from the literature. The mechanism was validated against experimental results from batch reactors, flow reactors, shock tubes, and premixed flames. This is the accepted manuscript version of the published article.
Date:
August 5, 2020
Creator:
Glarborg, Peter; Andreasen, Charlotte S.; Hashemi, Hamid; Qian, Rachel & Marshall, Paul
Object Type:
Article
System:
The UNT Digital Library
Acetaldehyde oxidation at elevated pressure
A detailed chemical kinetic model for oxidation of CH3CHO at intermediate to high temperature and elevated pressure has been developed and evaluated by comparing predictions to novel high-pressure flow reactor experiments as well as shock tube ignition delay measurements and jet-stirred reactor data from literature. The flow reactor experiments were conducted with a slightly lean CH3CHO/O2 mixture highly diluted in N2 at 600–900 K and pressures of 25 and 100 bar. This is the accepted manuscript version of the published article.
Date:
April 10, 2021
Creator:
Hashemi, Hamid; Christensen, Jakob M.; Marshall, Paul & Glarborg, Peter
Object Type:
Article
System:
The UNT Digital Library
Experimental and kinetic modeling study of oxidation of acetonitrile
Article asserts that oxidation of acetonitrile has been studied in a flow reactor in the absence and presence of nitric oxide. A detailed chemical kinetic model for oxidation of acetonitrile was developed, based on a critical evaluation of data from literature. This is the accepted manuscript version of the published article.
Date:
April 10, 2021
Creator:
Alzueta, María U.; Guerrero, Marta; Millera, Angela; Marshall, Paul & Glarborg, Peter
Object Type:
Article
System:
The UNT Digital Library
Selective Noncatalytic Reduction of NOx Using Ammonium Sulfate
Article discusses how ammonium sulfate (AS) is of interest as an additive in stationary combustion plants for the simultaneous control of NOx (through selective noncatalytic reduction, SNCR) and deposition and corrosion (through sulfation of alkali chlorides). The results indicated that sulfur from ammonium sulfate is mainly released as SO3, even though SO2 is detected in increasing concentrations at temperatures above 1000 °C. This is the accepted manuscript version of the published article.
Date:
July 15, 2021
Creator:
Krum, Kristian R. K.; Jensen, Martin; Li, Songgeng; Norman, Thomas; Marshall, Paul; Wu, Hao et al.
Object Type:
Article
System:
The UNT Digital Library
Kinetic fall-off behavior for the Cl + Furan-2,5-dione (C4H2O3, maleic anhydride) reaction
Article discusses how rate coefficients, k, for the gas-phase Cl + Furan-2,5-dione (C4H2O3, maleic anhydride) reaction were measured over the 15–500 torr (He and N2 bath gas) pressure range at temperatures between 283 and 323 K. An atmospheric degradation mechanism for C4H2O3 is proposed based on the observed product yields and theoretical calculations of ring-opening pathways and activation barrier energies at the CBS-QB3 level of theory. This is the accepted manuscript version of the published article.
Date:
February 15, 2021
Creator:
Chattopadhyay, Aparajeo; Gierczak, Tomasz; Marshall, Paul; Papadimitriou, Vassileios C. & Burkholder, James B. (James Bart), 1954-
Object Type:
Article
System:
The UNT Digital Library