Article
Chemistry, Multidisciplinary
Patrick K. Tamukong, Mark R. Hoffmann
Summary: The GVVPT2 method was used to study the low-lying electronic states of Ni-2, revealing a large number of low-lying states correlated with the D-3(3) + D-3(3) dissociation limit. The ground state was identified as X(1)Gamma(g), with spectroscopic constants in agreement with experimental values when scalar relativistic effects were considered.
FRONTIERS IN CHEMISTRY
(2021)
Article
Chemistry, Physical
Agnieszka Stanczak, Jakub Chalupsky, Lubomir Rulisek, Michal Straka
Summary: In this study, the performance of various composite computational protocols for CBC sites was comprehensively calibrated and evaluated. Several calibrated DFT functionals were selected for the study of [Cu2O2] inorganic systems.
Article
Engineering, Chemical
Zhengwen Wei, Yifan Du, Xiang-fei Lu, Wei Wang, Roberta Del Sole, Giuseppe Mele, Zhen-Yi Jiang
Summary: In this study, a novel Fe3O4-terephthalaldehyde (Fe3O4-TERE) magnetic nanomaterial was fabricated using encapsulation and grafting technique, which effectively reduced the contamination risk of phenanthrene (PENE) and its degradation intermediate, 9-phenanthrol (9-PENE). The Fe3O4-TERE also demonstrated excellent regeneration performance and provided profound theoretical perspectives for analyzing the adsorption mechanism. This research proposed a promising fabrication strategy for removing and remediating polycyclic aromatic hydrocarbons contamination.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Optics
A. Souza Barbosa, M. Mendes, N. C. Jones, S. V. Hoffmann, M. H. F. Bettega, M. J. Brunger, P. Limao-Vieira
Summary: In this study, the absorption spectrum of ethanol in the range of 5.64-10.78 eV (220-115 nm) was investigated using ab initio theoretical and experimental methods. The results show that the photolysis lifetime of ethanol in the Earth's atmosphere is short and solar photolysis has a weak impact on the atmosphere.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2022)
Article
Engineering, Geological
Yong Fu, Yong Liu
Summary: This study systematically examines the effects of fin length-width ratio, fin surface area, fin position, and fin shape on the embedment depth and time-dependent holding capacity of Dynamically Installed Anchors (DIAs) through experimental and theoretical approaches. It was found that DIA models with short-wide-rectangular fins at the rear achieve better performance in terms of embedment depth and holding capacity. The theoretical assessment of nine types of finned DIAs provides practical implications for the design of DIAs in practice.
CANADIAN GEOTECHNICAL JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
Soumaya Manai, Dhia Elhak Salhi, Sirine Ben Nasr, Haikel Jelassi
Summary: In this study, accurate energy levels were provided for the lowest singly excited and doubly excited levels of helium-like ions with Z = 5 - 9. The calculations also included wavelengths, weighted oscillator strengths, transition rates, and lifetimes for different multipole transitions. The results were compared with other theories and data from the NIST database, showing good agreement and providing important atomic data for doubly excited states.
RESULTS IN PHYSICS
(2022)
Article
Optics
S. Kumar, D. Duflot, S. Hoffmann, N. C. Jones, P. Bolognesi, L. Carlini, R. Richter, L. Avaldi, M. J. Brunger, P. Limao-Vieira
Summary: In this study, gas-phase electronic states of 2,4,6-trichloroanisole (TCA) were investigated for the first time using synchrotron radiation for photoabsorption and photoelectron spectroscopy. The high-resolution vacuum ultraviolet photoabsorption spectrum was measured, electronic transitions were comprehensively reported, and the photolysis lifetime of TCA in the upper stratosphere was estimated using the measured absolute photoabsorption cross sections.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2021)
Article
Astronomy & Astrophysics
Zhi Qin, Peigen Hu, Tianrui Bai, Linhua Liu
Summary: This study calculates the potential energy curves and transition dipole moments of four electronic states of O-2, and estimates the temperature-dependent photodissociation cross sections and rates. The results are important for understanding Earth's atmospheric chemistry and exploring exoplanetary atmospheres.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Chemistry, Physical
Cynthia B. Rivela, Alejandro L. Cardona, Maria B. Blanco, Ian Barnes, Martina Kieninger, Oscar N. Ventura, Mariano A. Teruel
Summary: The gas-phase reaction products of 2-fluoropropene with Cl atoms were determined experimentally for the first time. The reaction mechanism was elucidated through theoretical calculations. The main products were acetyl fluoride and formyl chloride. The reaction was found to primarily occur via addition to the C alpha carbon, with no products expected from the abstraction channel.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Inorganic & Nuclear
Jia Guan, Zeyi Guo, Xuelian Li, Hao Tang
Summary: Looking back at the complexity caused by the noninnocent ligands in determining the oxidation state of the transition metal and correlating it with reactivity, the reactions of alkene/alkyne addition to rhenium/ruthenium tris(thiolate) complexes provide valuable insights into the chemistry of the dppbt ligand, including its noninnocent nature, ligand-centered mechanism, and the origin of differential reactivity.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
F. M. Mustafa, Mahmoud K. Abdel K. Latif, Ahmed A. Abdel A. Khalek
Summary: The efficiency of D-pi-A organic dyes in dye-sensitized solar cells (DSSCs) is explored. Quantum mechanics calculations are used to assess the performance of five dyes with different acceptor sizes and geometric structures. By fabricating high-efficiency DSSCs with these dyes, their performance as light-harvesting sensitizers is evaluated. Analyzing their structural and functional properties helps us understand their effectiveness as sensitizers.
Article
Astronomy & Astrophysics
Karlis Dzenis, Alexandre Faure, B. A. McGuire, A. J. Remijan, P. J. Dagdigian, C. Rist, R. Dawes, E. Quintas-Sanchez, F. Lique, M. Hochlaf
Summary: The theoretical rotational cross sections for propylene oxide colliding with cold He atoms were obtained using a high-accuracy potential energy surface. The results were combined with radiative data and analyzed using a non-LTE radiative transfer model, revealing the cold gas characteristics of propylene oxide in the Sgr B2(N) molecular cloud.
ASTROPHYSICAL JOURNAL
(2022)
Article
Thermodynamics
Chao Yan, Hao Zhao, Ziyu Wang, Guohui Song, Ying Lin, Clayton R. Mulvihill, Ahren W. Jasper, Stephen J. Klippenstein, Yiguang Ju
Summary: This study investigates the oxidation reactions of dimethyl ether (DME) under high pressure conditions using a supercritical pressure jet-stirred reactor (SP-JSR). The results show weakened NTC behavior and a shift in the intermediate-temperature oxidation window at high pressure. The study updates the reaction rate models for several important reactions, improving the predictability for key species.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Jie Jian, Hamid Hashemi, Hao Wu, Ahren W. Jasper, Peter Glarborg
Summary: This study updated the reaction mechanism of ozone in combustion and validated the simulation results. The experimental data provided insights into the competition between ozone and hydrogen, and constrained the rate constants of key reactions. Comparison between experiments and model predictions showed good agreement for ozone dissociation, but only the present mechanism accurately predicted the hydrogen-ozone reaction rate.
Article
Biochemistry & Molecular Biology
Alexandre C. R. Gomes, Carlos M. R. Rocha, Ahren W. Jasper, Breno R. L. Galvao
Summary: Phosphorus is a key element in biological molecules and understanding its role in astrochemistry and atmospheric chemistry may provide insights into its availability on Earth. PO molecule serves as one of the main reservoirs of phosphorus in the interstellar medium (ISM), and studying its formation mechanisms and rate coefficients is crucial for abundance modeling.
JOURNAL OF MOLECULAR MODELING
(2022)
Article
Chemistry, Physical
Zhenghai Yang, Srinivas Doddipatla, Chao He, Shane J. Goettl, Ralf Kaiser, Ahren W. Jasper, Alexandre C. R. Gomes, Breno R. L. Galvao
Summary: In this study, we provide strong evidence that three-body collisions between molecular hydrogen and long-lived reaction intermediates are prevalent inside cold molecular clouds. This concept may be applicable to reactions involving polycyclic aromatic hydrocarbons, offering a versatile mechanism for the formation of complex organics.
Article
Physics, Multidisciplinary
Ahren W. Jasper, Daniel R. Moberg, Yujie Tao, Stephen J. Klippenstein, Raghu Sivaramakrishnan
Summary: The thermal QCTs rate constants for the H + HO2 reaction are demonstrated to be up to 50% smaller than TST rate constants due to inefficient intramolecular vibrational energy redistribution in the transient H2O2 well, with the reduction factor increasing with temperature. Furthermore, the rate constants for H + HO2 reactions mediated by H2O2 are shown to inversely depend on the initial vibrational excitation of HO2.
FRONTIERS IN PHYSICS
(2022)
Article
Chemistry, Physical
Jyoti S. Campbell, Klaas Nauta, Christopher S. Hansen, Scott H. Kable
Summary: A new technique for determining absolute photodissociation quantum yields in a molecular beam is reported. The technique utilizes two available product channels in a molecule and directly measures the relative product yield of each channel without the need for external calibration. The technique is demonstrated using the photochemistry of HCHO and yields results consistent with established quantum yields.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Biographical-Item
Chemistry, Physical
Joel M. Bowman, Scott H. Kable, Arthur G. Suits
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Talitha M. Selby, Fabien Goulay, Satchin Soorkia, Amelia Ray, Ahren W. Jasper, Stephen J. Klippenstein, Alexander N. Morozov, Alexander M. Mebel, John D. Savee, Craig A. Taatjes, David L. Osborn
Summary: The mechanism of hydrocarbon ring growth in sooting environments is still debated. This study investigates the reaction between phenyl radical and propargyl radical and finds that at temperatures of 300-1000 K, two isomers, C9H8 and C9H7 + H, are formed. Further calculations and experiments suggest that the involvement of H atoms contributes to the formation of polycyclic aromatic hydrocarbon's second ring.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Education & Educational Research
Scott A. Reid
Summary: General chemistry I/II courses are crucial for STEM majors, as poor performance in these courses is often linked to lower student success and retention rates. This article presents a unique approach of developing a bridging or intervention course to assist students who have not succeeded in general chemistry I and help them prepare for retaking the course in the following semester or summer.
EDUCATION SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Matthew M. Yung, Calvin Mukarakate, Kristiina Iisa, A. Nolan Wilson, Mark R. Nimlos, Susan E. Habas, Abhijit Dutta, Kinga A. Unocic, Joshua A. Schaidle, Michael B. Griffin
Summary: The production of advanced biofuels has the potential to reduce greenhouse gas emissions in the heavy vehicle transportation sector. However, there are barriers that need to be overcome, including catalyst and process development to reduce costs and improve carbon utilization, as well as industry validation to de-risk scale-up. This study addresses these challenges through an integrated two-step process, showing the potential to generate low-carbon transportation fuels and chemical co-products with reduced emissions.
Article
Chemistry, Physical
Anurag Kumar, Rongyue Wang, Kellene A. Orton, Kurt M. Van Allsburg, Calvin Mukarakate, Evan C. Wegener, Qiyuan Wu, Susan E. Habas, Krzystof Z. Pupek, Joseph A. Libera, Frederick G. Baddour
Summary: In this work, a scalable and continuous synthesis method, flame-spray pyrolysis (FSP), was used to produce nanostructured Pt/TiO2 catalysts for biomass conversion. The catalysts prepared via FSP showed distinct Pt speciation and tunable properties by varying the Pt loading. These catalysts exhibited comparable catalytic activity to those prepared by conventional incipient wetness impregnation (IW) for upgrading biomass vapours, with the added advantage of greater control over the product slate. Preliminary cost analysis identified key drivers that can be addressed to improve the economic viability of the FSP synthesis.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Geetanjali Yadav, Avantika Singh, Abhijit Dutta, Taylor Uekert, Jason S. DesVeaux, Scott R. Nicholson, Eric C. D. Tan, Calvin Mukarakate, Joshua A. Schaidle, Cody J. Wrasman, Alberta C. Carpenter, Robert M. Baldwin, Yuriy Roman-Leshkov, Gregg T. Beckham
Summary: This study analyzed the technical and economic characteristics of catalytic fast pyrolysis of waste plastics and found that converting the waste plastics into aromatic compounds can be cost-competitive and reduce energy consumption. However, this technology results in an increase in greenhouse gas emissions. The study also found that different catalytic fast pyrolysis processes have varying economic and environmental benefits.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Physical
Talitha M. Selby, Fabien Goulay, Satchin Soorkia, Amelia Ray, Ahren W. Jasper, Stephen J. Klippenstein, Alexander N. Morozov, Alexander M. Mebel, John D. Savee, Craig A. Taatjes, David L. Osborn
Summary: The reaction mechanism of hydrocarbon ring growth in sooting environments is still a topic of debate. This study focuses on the reaction between phenyl radical and propargyl radical, and investigates the effect of temperature on product formation. Experimental data and theoretical calculations suggest that as temperature increases, additional isomers are formed, potentially due to the contribution of hydrogen atom reactions.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Ahren W. Jasper
Summary: The study predicts low-pressure-limit microcanonical and thermal rate constants using automated ab initio potential energy surface construction, classical trajectories, transition state theory, and detailed energy- and angular-momentum-resolved collision kernel. The a priori approach shows excellent agreement with experimental results, with average deviations of less than 25%.
FARADAY DISCUSSIONS
(2022)
