Thermochemistry - Science topic

The cubic SrVO 3 perovskite oxide is an attractive candidate for high-temperature energy applications due to its favourable features, such as multiple oxidation states cations, high structural and thermal stabilities, ability to accommodate large number of oxygen vacancies, and cost-effectiveness. Herein, the temperature dependent reduction propert...

The abundances of main carbon- and oxygen-bearing gases in the atmospheres of giant exoplanets provide insights into atmospheric chemistry and planet formation processes1,2. Thermochemistry suggests that methane (CH4) should be the dominant carbon-bearing species below about 1,000 K over a range of plausible atmospheric compositions³; this is the c...

Recycling cathode materials from spent lithium‐ion batteries (LIBs) is critical to a sustainable society as it will relief valuable but scarce recourse crises and reduce environment burdens simultaneously. Different from conventional hydrometallurgical and pyrometallurgical recycling methods, direct regeneration relies on non‐destructive cathode‐to...

A new polymorphic modification of lanthanum sulfate was obtained by thermal dehydration of the respective nonahydrate. According to powder X-ray diffraction, it was established that b�-La2(SO4)3 crystallized in the C2/c space group of the monoclinic system with the KTh2(PO4)3 structure type (a = 17.6923(9), b = 6.9102(4), c = 8.3990(5) Å, b = 100.3...

This comprehensive monograph is primarily intended to describe the patented FerWIN® technology, a green and zero-carbon iron-making process, which consists to perform the electrowinning of iron metal and the recycling of sulfuric acid from iron sulfates that are by-produced at the million tons scale worldwide while releasing pure oxygen gas instead...

Modelling galaxy formation in hydrodynamic simulations has increasingly adopted various radiative transfer methods to account for photoionization feedback from young massive stars. However, the evolution of H ii regions around stars begins in dense star-forming clouds and spans large dynamical ranges in both space and time, posing severe challenges...

Nickel sulfide concentrates are important source for production of battery-grade nickel sulfate. They are commonly associated with cobalt, PGMs and may contain significant amount of copper. Recycling of electronics and batteries would bring even more copper into the process. Sustainable operation of such processes requires accurate prediction of th...

The reforming of light hydrocarbons to produce synthesis gas, H2 and CO, is an important intermediate for manufacturing valuable basic chemicals and synthesis fuels. In order to understand these reforming processes better, elementary step reaction mechanisms are developed. In the available literature, the surface reaction mechanisms are usually ach...

When fullerenes 60 capture an alkali metal M − C_60 , they acquire a powerful permanent dipole. This suggests that if the system is in an inert atmosphere, like Argon, they tend to form dimers (M − C_60)2 , producing a gas whose thermodynamical properties can be studied. On this work, we focus on the degrees of freedom that appear when the dimer ha...

Atmospheric nitrogen may provide important constraints on giant planet formation. Following our semianalytical work, we further pursue the relation between observable NH 3 and an atmosphere’s bulk nitrogen abundance by applying the photochemical kinetics model VULCAN across planetary equilibrium temperature, mass, age, eddy diffusion coefficient, a...

Application of municipal solid and wood waste, as dominant sources of biomass, could be a promising alternative for producing energy from renewables via thermochemical gasification technology. In this paper, a study of thermogravimetric analysis (TGA) and excurrent gas composition produced by the municipal solid waste (MSW) and wood biomass gasific...

In this work, we present a comprehensive study of the thermodynamic properties of 3-and 4-ethoxyacetanilides. The heat capacities in crystalline, liquid, and supercooled liquid states from 80 to 475 K were obtained using adiabatic, differential scanning (DSC), and fast scanning (FSC) calorimetries. The fusion enthalpies at Tm were combined from DSC...

We have investigated the structure, stability, thermochemistry, and bonding in microhydrated N 2 O clusters (N 2 O‧W n (n = 1–12)). To do this we used various theoretical methods and techniques including density functional theory (DFT), quantitative molecular electrostatic potential surface (MESP), quantum theory of atoms in molecules (QTAIM), and...

We present in this work a new formalism for the rapid and accurate evaluation of the thermodynamic properties of compounds and solid solution end-members which are required in the high-throughput computational thermochemistry discovery of new materials. The method is based on the Debye approximation and is fully thermodynamically self-consistent. I...

In thermochemistry experiments, a large volume and relatively high concentration of chemicals are often used to get a significant temperature change using an analogue thermometer. A ‘greener’ experimental protocol is developed as an alternative using modern microcontroller boards, ChemDuino. The aim of this research is to develop a low-cost and poc...

O presente trabalho tratou de determinados princípios da Termoquímica a partir da Aprendizagem Significativa, com abordagem teórica-metodológica da Atividade Experimental Problematizada (AEP) no desenvolvimento de habilidades cognitivas, na perspectiva da Taxonomia de Bloom Revisada (TBR). A pesquisa foi do tipo pesquisa-intervenção, com abordagem...

Thermochemistry is a material high school students study in class XI MIPA in odd semesters. In this material, 83.69% of SMAN 13 Padang class XI MIPA students still need to achieve the minimum completeness criteria set. It indicates that students have learning difficulties. Learning difficulties are failures to attain learning goals characterized by...

The splitting of carbon dioxide through the two-step solar thermochemical cycle presents enormous potential, for it holds the dual functionalities of solar fuel production and carbon-based energy recovery. However, the industrialization of this technology is impeded by two critical factors: The absence of fully developed oxygen carriers and advance...

This paper is based on a lecture Navrotsky gave honouring the memory of Paul McMillan. It summarizes our recent findings in the thermodynamics of hybrid materials including metal organic frameworks (MOFs), polymer-derived ceramics (PDCs) and ionic organic–inorganic compounds. This work describes the main structure types and their corresponding ther...

The regularized and restored semi-local meta-generalized gradient approximation (meta-GGA) exchange-correlation functional r²SCAN [J. W. Furness, A. D. Kaplan, J. Ning, J. P. Perdew, and J. Sun, J. Phys. Chem. Lett. 11, 8208–8215 (2020)] is used to create adiabatic-connection-derived global double-hybrid functionals employing spin-opposite-scaled M...

Despite its simplicity and relatively low computational cost, second-order M{\o}ller-Plesset perturbation theory (MP2) is well-known to overbind noncovalent interactions between polarizable monomers and some organometallic bonds. In such situations, the pairwise-additive correlation energy expression in MP2 is inadequate. Although energy-gap depend...

Noncovalent interactions, such as dispersion, play a significant role in the stability of flexible molecules, such as curcumin. This study revealed the importance of dispersion correction in the structure and keto–enol tautomerization of curcumin, which has rarely been addressed in computational studies. We rigorously constructed all possible uniqu...

En la agroindustria se genera una considerable cantidad de residuos, los cuales pueden ser tratados usando diversas tecnologías termoquímicas como la carbonización hidrotermal. El rendimiento y contenido de carbono de biomasas son dos de las características más comunes que se estudian dentro del proceso generado en estas tecnologías tecnoquímicas,...

While researchers have extensively studied the initial decomposition mechanism of Monomethylhydrazine (MMH, CH3NHNH2) in the MMH/dinitrogen tetroxide (NTO) system, the investigation of Unsymmetrical Dimethylhydrazine (UDMH, (CH3)2NNH2) has been limited due to its high toxicity, corrosiveness, and deterioration rate. Hence, the effects of UDMH’s det...

The unfavorable scaling (N5) of conventional second-order Møller-Plesset theory (MP2) typically prevents the application of double-hybrid (DH) density functionals to large systems with more than 100 atoms. A prominent approach to reduce the computational demand of electron correlation methods is the domain-based local pair natural orbital (DLPNO) a...

As fibras naturais lignocelulósicas (FNLs) são materiais de origem vegetal que apresentam em sua composição a celulose, a hemicelulose e a lignina. Esses materiais são abundantes na natureza e têm despertado grande interesse em diversos setores da indústria devido às suas propriedades físicas e químicas. As FNLs podem ser obtidas de diversas fontes...

Validity and practicality are important elements in an e-book because it shows the accuracy and feasibility of the teaching material before it is used. This study aimed to determine the validity and practicality of teaching materials in interactive e-books based on SETS (Science, Environment, Technology, and Society) on thermochemical materials. Th...

The era of the industrial revolution 4.0, teachers will deal with children who are very intense with gadgets or other technology. This is a challenge in the learning process. This article aims to produce a learning system with digital literacy based guided inquiry integrated flipped classroom using Discord application on thermochemistry and determi...

La producción de energía genera la mayor parte de las emisiones de gases de efecto invernadero (GEI) porque la matriz energética mundial se basa, predominantemente, en combustibles fósiles. En este contexto, las tecnologías de valorización energética de residuos (WtE por sus siglas en inglés) pueden representar una opción para una transición hacia...

This study investigates the use of machine learning (ML) to correct the enthalpy of formation (Hf) from two separate DFT functionals, PBE and SCAN, to the experimental Hf across 1011 solid-state compounds. The ML model uses a set of 25 properties that characterize the electronic structure as calculated using PBE and SCAN. The ML model significantly...

Within the cold regions of space, ices that are enriched with carbon monoxide (CO) molecules are exposed to ionizing radiation, which triggers new reactions and desorption processes. Laboratory studies on astrochemical ices employing different projectiles have revealed the appearance of several new species. In this study, we employed the upgraded P...

Este material didático é elaborado com base nos estudos e em uma experiência em situação real de sala de aula, com o uso de histórias em quadrinhos (HQs) em uma turma do segundo ano do Ensino Médio. Inicialmente, trazemos alguma discussão a respeito das HQs e possibilidades para sua utilização na disciplina de Química a partir dos resultados discut...

1.A Comparative Statistical Study of the Geochemistry of.... The present research is aimed at statistically analyzing two data sets drawn from two distinct geologic-tectonic regimes having two distinct geological and tectonic settings - one very tectonically active Alpine-Himalayan mountain chains of Extra-Peninsular and the other very stable land...

A trajetória do Núcleo de Residência Pedagógica do curso de Licenciatura em Química da UFRRJ no contexto do ensino remoto imposto pela pandemia da COVID-19 no ano letivo de 2021 é apresentada e discutida. As atividades pedagógicas foram desenvolvidas em dois colégios da rede Estadual de Ensino do Rio de Janeiro (SEEDUC), sendo uma escola localizada...

Global reactivity descriptors of isopropyl acetate (IPA) and thermo-kinetic aspects of its oxidation via OH radicals have been studied. Transition state theory (TST) was utilized to estimate the bimolecular rate constants. Ten oxidation pathways have been investigated, and all of them are exothermic. The potential energy diagram has been sketched u...

3D-RISM-KH molecular solvation theory based on statistical mechanics has been an engine of the multiscale methods framework, which also includes molecular simulation techniques. Its applications range from the solvation energy of small molecules to the phase behavior of polymers and biomolecules. Molecular solvation theory predicts and explains the...

Jupiter's oxygen content is inextricably tied to its formation history and the evolution of the early solar system. Recent one-dimensional thermochemical modeling of CO showed that the planet's bulk water content could be subsolar, in stark contrast to the water enrichment determined near the equator using the Juno spacecraft. Here, we use a hydrod...

This chapter aimed to estimate the calorific value and potential of electrical energy that can be generated from the organic fraction of municipal solid waste through mathematical models, bioconversion, and thermochemical approach. The calorific values were calculated using the empirical relationship between higher heating value and ultimate analys...

Molten salt reactors (MSRs) are innovative advanced nuclear reactors that utilize nuclear fuel by dissolving it in a high-temperature liquid salt. This unique feature differentiates MSRs from other types of reactors and allows for enhanced safety and economic performance. The liquid fuel also entails several multiphysics effects that can complicate...

A comprehensive thermodynamic study of the Water gas shift (WGS) reaction was investigated using density functional theory (DFT). Chemisorption involves the formation of new chemical bonds between adsorbed species and atoms of the substrate. Adsorbates dissociate on the metal surface because of weaker intermolecular bonds on the surface. The adsorp...

ABSTRAK: Penelitian ini bertujuan: (1) mengidentifikasi konteks-konteks budaya lokal yang relevan dengan materi kimia di SMA, dan (2) mendeskripsikan pan-dangan guru-guru kimia terhadap integrasi konteks budaya lokal dalam pembela-jaran kimia di SMA. Penelitian dilakukan melalui studi dokumen dan studi lapang-an. Data yang diperoleh dalam penelitia...

A thermodynamic model is developed using a one-dimensional model, LOGEcat to understand the dry reforming of methane over nickel-based catalysts. To do so, we have extended our previously developed mechanism (Rakhi and Shrestha in React Kinet, Mech Catal 135:3059–3083, 2022) which contains 21 reversible reactions by adding 5 more reversible reactio...

Many important industrial processes rely on heterogeneous catalytic systems. However, given all possible catalysts and conditions of interest it is impractical to optimize most systems experimentally. Automatically generated microkinetic models can be used to efficiently consider many catalysts and conditions. However, these microkinetic models req...

Oxidative stress and metal dyshomeostasis are considered crucial factors in the pathogenesis of Alzheimer’s disease (AD). Indeed, transition metal ions such as Cu(II) can generate reactive oxygen species (ROS) via O2 Fenton-like reduction, catalyzed by Cu(II) coordinated to the amyloid-beta (Aβ) peptide. Despite intensive efforts, the mechanisms of...

A pirólise é um processo termoquímico com potencial para fomentar a bioeconomia circular dentro da cadeia de tratamento dos resíduos sólidos. O presente estudo investiga a conversão termoquímica de borra de café (BC) (resíduo agroindustrial) e resíduo da evaporação de lixiviado concentrado (LC) de aterro sanitário. Os objetivos específicos incluem...

Undesired solid precipitation in coal slag at high temperatures can cause serious blockages, or even the shutdown of coal gasifiers, due to a rapid increase in slag viscosity. In this study, the solid precipitation behaviors of coal slag from different primary phases and under different atmospheres were both experimentally and theoretically investi...

Uridine phosphorylases are used for biotechnological synthesis of pyrimidine derivatives and, moreover, their substrates and inhibitors are used in medicine. Therefore, studies of the mechanisms of the chemical reaction catalyzed by the enzyme and its specificity for various substrates are relevant. The research into the enzymatic reaction main sta...

Aerosol particles are important for our global climate, but the mechanisms and especially the relative importance of various vapors for new particles formation (NPF) remain uncertain. Quantum chemical (QC) studies on organic enhanced nucleation has for the past couple of decades attracted immense attention, but very little remains known about the e...

Diketene (4-methylideneoxetan-2-one) is a precursor to the formation of either two molecules of ketene, or allene and CO 2 using pyrolysis techniques. It is not known experimentally which of these pathways is followed, or indeed if both are, during the dissociation process. We use computational methods to show that the formation of ketene has a low...

X-ray radiation, in particular radiation between 0.1 keV and 10 keV, is evident from both point-like sources, such as compact objects and T-Tauri young stellar objects, and extended emission from hot, cooling gas, such as in supernova remnants. The X-ray radiation is absorbed by nearby gas, providing a source of both heating and ionization. While p...

The physical properties of regional seismic discontinuities in the upper mantle yield insights into lateral and radial thermochemical variations, with implications for our understanding of magmatism and convection in the mantle.The global distribution of the 300-km discontinuity (termed the "X" discontinuity) is relatively poorly resolved, as it is...

The availability of thermochemical properties allows for the prediction of the equilibrium compositions of chemical reactions. The accurate prediction of these can be crucial for the design of new chemical synthesis routes. However, for new processes, these data are generally not completely available. A solution is the use of thermochemistry calcul...

Silicate vapors play a key role in planetary evolution, especially dominating early stages of rocky planet formation through outgassed magma ocean atmospheres. Our open-source thermodynamic modeling software “VapoRock” combines the MELTS liquid model with gas-species properties from multiple thermochemistry tables. VapoRock calculates the partial p...

[5.5.5.5]hexaene is a [12]annulene ring with a symmetrically bound carbon atom in its center. This is the smallest hydrocarbon with a hyperbolic paraboloid shape. [5.5.5.5]hexaene and related hydrocarbons are important building blocks in organic and materials chemistry. For example, penta-graphene—a puckered 2D allotrope of carbon—is comprised of s...

While the dissociative recombination (DR) of ground-state molecular ions with low-energy free electrons is generally known to be exothermic, it has been predicted to be endothermic for a class of transition-metal oxide ions. To understand this unusual case, the electron recombination of titanium oxide ions (TiO ⁺ ) with electrons has been experimen...

Calculation of molecular geometries and harmonic vibrational frequencies are pre-requisites for thermochemistry calculations. Contrary to conventional wisdom, this paper demonstrates that quantum chemical predictions of the thermochemistry of many chemical reactions appear to be very insensitive to the choice of basis sets. For a large test set of...

Recent high angular resolution ALMA observations have revealed numerous gaps in protoplanetary disks. A popular interpretation has been that planets open them. Most previous investigations of planet gap-opening have concentrated on viscous disks. Here, we carry out 2D (axisymmetric) global simulations of gap opening by a planet in a wind-launching...

This study was conducted to analysis properness of thermochemistry teaching material in chemistry school textbook which is used in most SMA/MA in Kota Bandung based on criteria of selection stage of Four Steps Teaching Material Development (4STMD) method. The type of research is evaluative research by content analysis method. There are three criter...

Adsorption of Methyl Green dye using Fava Bean Peel Waste was investigated in detail by conducting batch kinetic, thermodynamic and desorption experiments. Experimental data found appear that adsorption method was highly dependent on equilibrium time, adsorbent amount, and initial concentration of dye and pH solution. The sorption equilibrium for M...

A quantum chemical study has been presented on the decomposition of CH3CH2C(O)OCH(O•)CH3 which is derived from ethyl propionate (CH3CH2C(O)OCH2CH3) using the M06-2X/6-31 + G(d,p) level of theory. The thermal decomposition of CH3CH2C(O)OCH(O•)CH3 is essential to understand the chemistry of combustion of ethyl propionate. Here, the decomposition and...

El proceso de transformación termoquímica de los materiales lignocelulósicos en carbón se denomina pirólisis, y, tradicionalmente, se lleva a cabo en hornos de combustión interna en los cuales existe una barrera física para controlar el ingreso de oxígeno, compuesta por diversos materiales. Los rendimientos rondan el 25-30%, debido a que parte de l...

Catalytic upcycling of plastics results in a complex network of potentially thousands of reactions and intermediates. Manual analysis of such a network using ab initio methods to identify plausible reaction pathways and rate-controlling steps is intractable. Here, we combine informatics-based reaction network generation and machine learning based t...