The Mpemba effect is the name given to the observation that a liquid which is initially hot can freeze faster than the same liquid which begins cold, under otherwise similar conditions. There is disagreement about its theoretical basis and the parameters required to produce the effect.
In thermodynamics, nucleation is the first step in the formation of either a new thermodynamic phase or structure via self-assembly or self-organization within a substance or mixture. Nucleation is typically defined to be the process that determines how long an observer has to wait before the new phase or self-organized structure appears. For example, if a volume of water is cooled significantly below 0 °C, it will tend to freeze into ice, but volumes of water cooled only a few degrees below 0 °C often stay completely free of ice for long periods (supercooling). At these conditions, nucleation of ice is either slow or does not occur at all. However, at lower temperatures nucleation is fast, and ice crystals appear after little or no delay.
In the context of chemistry, molecular physics, physical chemistry, and molecular modelling, a force field is a computational model that is used to describe the forces between atoms within molecules or between molecules as well as in crystals. Force fields are a variety of interatomic potentials. More precisely, the force field refers to the functional form and parameter sets used to calculate the potential energy of a system on the atomistic level. Force fields are usually used in molecular dynamics or Monte Carlo simulations. The parameters for a chosen energy function may be derived from classical laboratory experiment data, calculations in quantum mechanics, or both. Force fields utilize the same concept as force fields in classical physics, with the main difference being that the force field parameters in chemistry describe the energy landscape on the atomistic level. From a force field, the acting forces on every particle are derived as a gradient of the potential energy with respect to the particle coordinates.
The Hofmeister series or lyotropic series is a classification of ions in order of their lyotrophic properties, which is the ability to salt out or salt in proteins. The effects of these changes were first worked out by Franz Hofmeister, who studied the effects of cations and anions on the solubility of proteins.
In computational chemistry, a water model is used to simulate and thermodynamically calculate water clusters, liquid water, and aqueous solutions with explicit solvent. The models are determined from quantum mechanics, molecular mechanics, experimental results, and these combinations. To imitate a specific nature of molecules, many types of models have been developed. In general, these can be classified by the following three points; (i) the number of interaction points called site, (ii) whether the model is rigid or flexible, (iii) whether the model includes polarization effects.
George Chappell Schatz, the Morrison Professor of Chemistry at Northwestern University, is a theoretical chemist best known for his seminal contributions to the fields of reaction dynamics and nanotechnology.
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification.
Timothy P. Lodge is an American polymer scientist.
Geraldine Lee Richmond is an American chemist and physical chemist who is serving as the Under Secretary of Energy for Science in the US Department of Energy. Richmond was unanimously confirmed by the United States Senate to her role on November 5, 2021. In this position, she oversees the Office of Science, the Applied Energy offices, and 13 of the 17 Department of Energy national laboratories. Before this appointment, Richmond served as a Professor of Physical Chemistry and held the Presidential Chair in Science at the University of Oregon. Her research has focused on understanding the chemistry and physics of complex surfaces and interfaces, using laser-based experimental and theoretical computational methods. These understandings are most relevant to energy production, atmospheric chemistry and remediation of the environment. Throughout her career she has also worked to increase the number and success of women scientists in the U.S. and in many developing countries through the COACh program that she founded in 1999. She is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. In recognition of her scientific achievements and contributions to women in science, she received the National Medal of Science from President Obama in 2013.
Robert Walter Zwanzig was an American theoretical physicist and chemist who made important contributions to the statistical mechanics of irreversible processes, protein folding, and the theory of liquids and gases.
Amalendu Chandra is an Indian theoretical physical chemist, a professor and the head of the Department of Chemistry at the Indian Institute of Technology, Kanpur. He is known for his microscopic theories and simulations on liquids, interface and clusters. He is an elected fellow of the Indian Academy of Sciences and the Indian National Science Academy. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, in 2007, for his contributions to chemical sciences.
Klaas Wynne is a professor in the School of Chemistry at the University of Glasgow and chair of Chemical Physics. He was previously a professor in the Department of Physics at the University of Strathclyde (1996–2010).
Ambarish Ghosh is an Indian scientist, a faculty member at the Centre for Nano Science and Engineering (CeNSE), Indian Institute of Science, Bangalore. He is also an associate faculty at the Department of Physics. He is known for his work on nanorobots, active matter physics, plasmonics, metamaterials and electron bubbles in liquid helium.
Branka Maria Ladanyi was a Yugoslavian-born Croatian-American physical chemist, who spent her career in the department of chemistry at Colorado State University. Her research focused on structure and dynamics of liquids, broadly defined, which she studied using theoretical and computational techniques.
Nico van der Vegt is a Dutch chemist and a professor for computational physical chemistry at Technische Universität Darmstadt.
P. B. Sunil Kumar is an Indian physicist, professor and the founding director of IIT Palakkad, from January 2017 to September 2022. He also holds professorship(on lien) at Department of Physics, IIT Madras. He is known for his research on Soft matter and Biological Physics. He is an elected member of Kerala Science Congress.
Alfred G. Redfield was an American physicist and biochemist. In 1955 he published the Redfield relaxation theory, effectively moving the practice of NMR or Nuclear magnetic resonance from the realm of classical physics to the realm of semiclassical physics. He continued to find novel magnetic resonance applications to solve real-world problems throughout his life.
Devarajan (Dave) Thirumalai, an Indian-born American physicist, is the Collie-Welch Reagents Professor in Chemistry at the University of Texas at Austin. His research spans equilibrium and non-equilibrium statistical mechanics, such as the transition from liquid to amorphous state, polymer-colloid interactions, and protein and RNA folding. He is known for his contributions to the theories of protein/RNA folding, protein aggregation, glasses, and biological machines. He also does research in intrinsically disordered proteins (IDPs), organization and dynamics of chromosome and cell biophysics. Prior to moving to the University of Texas at Austin, he was a distinguished university professor in the University of Maryland from 2010 to 2015.
An ion network is an interconnected network or structure composed of ions in a solution. The term "ion network" was coined by Cho and coworkers in 2014. The notion of extended ion aggregates in electrolyte solutions, however, can be found in an earlier report. The ion network is particularly relevant in high-salt solutions where ions can aggregate and interact strongly and it has been investigated in an increasing number of research and review articles.
