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Calorimetry is a general method for determination of the rates of zero-order processes, but analysis of the data for the rate constant and reaction enthalpy is difficult because these occur as a product in the rate equation so evaluation of one requires knowledge of the other. Three methods for evaluation of both parameters, without prior knowledge, are illustrated with examples and compared with literature data. Method 1 requires the reaction to be studied in two buffers with different enthalpies of ionization. Method 2 is based on calculation of reaction enthalpy from group additivity functions. Method 3 applies when reaction progresses to completion. The methods are applied to the enzymatic hydrolysis of urea, the hydrolysis of acetylsalicylic acid, and the photodegradation of nifedipine, respectively.
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http://dx.doi.org/10.1021/jp302933f | DOI Listing |
J Sci Food Agric
September 2025
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, China.
Background: Understanding starch behavior under various processing conditions is important for the development of novel food products with tailored nutritional profiles. This study investigated changes to the structure and properties of native corn starch (NCS) and biomimetic starch-entrapped microspheres following thermal and enzymatic treatments.
Results: Heat-treated microspheres showed more birefringence and structural order than native starch, indicating incomplete gelatinization due to the alginate matrix.
Food Res Int
November 2025
School of Food Science and Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, PR China; Anqing Yixiu Green Food Innovation Research Institute, Anqing 246000, PR China. Electronic address:
This study presents a biopreservation method using sourdough co-fermented with Fructilactobacillus sanfranciscensis and Propionibacterium freudenreichii, optimizing conditions to 220 hydration and 24 h fermentation. The composite sourdough bread quality was evaluated through physicochemical, storage, sensory, and microbial tests, with mechanisms analyzed based on microstructure, rheology, and dough structure. Results showed that: first, the composite sourdough enhanced bread physicochemical properties, increasing volume, height-to-diameter ratio, elasticity, and resilience, while reducing baking loss, hardness, chewiness, and adhesiveness.
View Article and Find Full Text PDFACS Omega
September 2025
Molecule and Materials Modeling Laboratory, and Department of Chemistry, Can Tho University, Can Tho 94000 Viet Nam.
Computational approaches within the framework of density functional theory (DFT) are used to probe the effects of gold nanoparticles (AuNPs) on the antioxidant potency of gallic acid (HGA), which is a prototypical polyphenolic acid. Four small gold clusters, Au with = 2, 3, 6, and 11, are employed as simple models to simulate the surface of AuNPs. The antioxidant capacity is evaluated through the ability to donate a hydrogen atom and to transfer an electron, which are characterized by the bond dissociation enthalpy (BDE) and ionization energy (IE) of the antioxidant, respectively.
View Article and Find Full Text PDFJ Mol Model
September 2025
College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 210009, China.
Context: High-nitrogen polycyclic compounds have become a research hotspot in the design of new energetic molecules due to their dense nitrogen content, high positive enthalpy of formation, and good structural stability. In particular, the fused structures of triazole and triazine heterocycles can not only enhance energy output but also possess excellent thermal stability. This study focuses on three triazolotriazine energetic compounds: 3,7-dinitro-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine (TTX), 7-nitro-3-(1H-tetrazol-5-yl)-[1,2,4]triazolo[5,1-c][1,2,4]triazin-4-amine (compound 1), and 3,3'-dinitro-[7,7'-bi[1,2,4]triazolo[5,1-c][1,2,4]triazine]-4,4'-diamine (compound 2).
View Article and Find Full Text PDFJ Phys Chem A
September 2025
National Key Laboratory of Solid Propulsion, School of Astronautics, Northwestern Polytechnical University, Xi'an 710072, China.
Unsymmetrical dimethylhydrazine (UDMH) is a widely used hypergolic rocket fuel. It is one of the most commonly used fuels for attitude control engines, such as those in missiles, satellites, spacecraft, and launch vehicles. We conducted a high-level theoretical study to develop a detailed combustion kinetic mechanism for UDMH, focusing on crucial elementary reactions.
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