Simon–Glatzel equation
The Simon-Glatzel equation is an empirical relationship used in geophysics and geological engineering to describe the mechanical behavior of rocks under varying stress conditions. Specifically, it relates to the behavior of rocks under triaxial stress, which occurs in many geological and engineering contexts.
Space-based solar power
Space-based solar power (SBSP) refers to the concept of collecting solar energy in space and transmitting it back to Earth for use as a renewable energy source. The fundamental idea is to deploy solar power satellites equipped with solar panels in orbit around the Earth, where they can capture sunlight without the atmospheric interference and day-night cycle limitations that ground-based solar power systems face.
Specific ion interaction theory
Specific Ion Interaction Theory (SIT) is a theoretical framework used to describe how ions interact in solution, particularly in the context of electrolyte solutions. Developed in the early 20th century, it extends the classical Debye-Hückel theory by taking into account specific interactions among ions rather than treating all ions uniformly. The main focus of SIT is on the influence of ionic strength and the specific chemical properties of individual ions on their behavior in solution.
Spiciness (oceanography)
In oceanography, "spiciness" refers to a property of seawater that combines variations in temperature and salinity, influencing the density of ocean water masses. This concept is crucial for understanding the mixing and movement of ocean currents, along with the distribution of temperature and salinity in the ocean.
Spinodal
The term "spinodal" is primarily used in the context of thermodynamics, specifically in phase separation processes in materials science and physical chemistry. It refers to a specific type of phase transition that occurs when a mixture is unstable and can separate into two or more distinct phases. In a broader sense, spinodal decomposition is a mechanism that describes how a homogeneous mixture becomes unstable. The spinodal curve defines the limits within which phase separation can occur spontaneously, even without nucleation.
Spinodal decomposition
Spinodal decomposition is a process that occurs in certain types of mixtures or solutions, particularly in the context of phase separation. It is a thermodynamic phenomenon that takes place when a single homogeneous phase becomes unstable under specific conditions, such as temperature or composition changes, leading to the spontaneous separation of the mixture into two or more distinct phases without the need for nucleation.
Spontaneous process
A spontaneous process is a physical or chemical change that occurs without the need for external energy inputs once it has begun. In other words, these processes are driven by natural tendencies of systems to move toward a state of lower energy or greater entropy (disorder). Spontaneous processes can happen at various rates; some occur quickly while others may be very slow.
Stack effect
The stack effect, also known as the chimney effect, is a phenomenon that occurs in buildings due to temperature differences between the indoor and outdoor environments. It is a natural ventilation process wherein warm air rises and exits through openings in the upper parts of a building, creating a pressure difference that draws in cooler air from lower openings.
Standard enthalpy of reaction
The standard enthalpy of reaction, often denoted as \( \Delta H^\circ \), is the change in enthalpy that occurs during a chemical reaction at standard conditions. Standard conditions typically refer to a temperature of 25 degrees Celsius (298.15 K), a pressure of 1 atmosphere (101.3 kPa), and concentrations of 1 mol/L for solutions.
Standard state
The term "standard state" refers to a specific set of conditions used as a reference point in thermodynamics, particularly in the fields of chemistry and materials science. It is essential for defining properties of substances and for comparing their thermodynamic data. The standard state of a substance is typically defined under the following conditions: 1. **Temperature**: 25 degrees Celsius (298.15 K). 2. **Pressure**: 1 atmosphere (101.3 kPa).
Standard Temperature and Pressure (STP) is a set of conditions commonly used in chemistry and physics to allow for the comparison of measurements and calculations. The standard conditions are defined as: - **Standard Temperature**: 0 degrees Celsius (273.15 Kelvin) - **Standard Pressure**: 1 atmosphere (atm), which is equivalent to 101.325 kilopascals (kPa) or 760 millimeters of mercury (mmHg).
State postulate
The State Postulate, also known as the State Principle, is a fundamental concept in thermodynamics and statistical mechanics. It asserts that the state of a thermodynamic system is completely defined by a set of macroscopic properties, or variables, and that these properties are sufficient to describe the system's state at a given moment.
Steam digester
A steam digester, often referred to in industrial and laboratory settings, is a type of pressure vessel that uses steam to heat and chemically treat materials. It is commonly used in the processing of wood, pulp, and other organic materials to break down complex compounds, facilitate digestion, and improve the extraction of valuable components. Steam digesters operate by introducing steam into the vessel, which raises the temperature and pressure inside.
Sulfidation
Sulfidation is a chemical process that involves the reaction of a substrate, typically a metal or alloy, with sulfur or sulfur-containing compounds. This process generally leads to the formation of sulfide compounds on the surface of the material. Sulfidation can occur under various conditions, such as high temperatures or specific chemical environments, and it is often associated with high-temperature applications, like those found in petrochemical processing or metallurgical processes.
Supersaturation
Supersaturation is a state of a solution in which the concentration of a solute exceeds its solubility limit at a given temperature and pressure. Under normal conditions, a solution will achieve saturation when no more solute can dissolve in a solvent at that specific temperature and pressure. However, in a supersaturated solution, the dissolved solute exceeds this equilibrium concentration.
Surroundings
The term "surroundings" generally refers to everything that is around a particular object, individual, or environment. It can vary in meaning based on the context in which it is used: 1. **General Context**: In everyday language, surroundings refer to the physical environment or the area around someone or something. This includes the landscape, buildings, people, and objects present in that space.
Sympathetic cooling
Sympathetic cooling is a technique used in physics and chemistry to cool an object without direct contact with a cooling medium. This method employs the interactions between particles to transfer heat through controlled means. In sympathetic cooling, a cold atomic or molecular species is used to absorb thermal energy from another species that needs to be cooled. For example, a cloud of ultracold atoms can cool a nearby ion or another type of particle.
Synergetics (Haken)
Synergetics is a framework developed by the German physicist Hermann Haken in the 1970s. It is a multidisciplinary approach that studies complex systems and the principles of self-organization, pattern formation, and collective behavior. Haken's work in synergetics combines ideas from physics, biology, psychology, and social sciences to understand how coherent structures and patterns emerge in systems made up of many interacting components.
TEOS-10
TEOS-10, or the Thermodynamic Equation of Seawater - 2010, is a comprehensive framework developed for the thermodynamic properties of seawater. It was established by the International Oceanographic Commission (IOC) and provides a consistent set of equations for calculating various physical properties of seawater, including temperature, salinity, pressure, density, sound speed, and chemical potential, under a wide range of conditions.
Temperature measurement
Temperature measurement is the process of determining the degree of heat or coldness of an object or environment. It is an essential parameter in various fields, including meteorology, medicine, engineering, and environmental science. Temperature is typically measured using various types of instruments known as thermometers, which can operate on different principles.