phase

Examples of phase in the following topics:

• Interpreting Phase Diagrams

  • The lines that separate these single phase regions are known as phase boundaries.
  • By focusing attention on distinct single phase regions, phase diagrams help us to understand the range over which a particular pure sample of matter exists as a particular phase.
  • When evaluating the phase diagram, it is worth noting that the solid-liquid phase boundary in the phase diagram of most substances has a positive slope.
  • With a knowledge of the major components of phase diagrams and the features of phase plots, a phase diagram can be used to understand how altering thermodynamic parameters influences the states/phases of matter a sample of a substance is in.
  • A typical phase diagram illustrating the major components of a phase diagram as well as the critical point.

• Major Features of a Phase Diagram

  • A phase diagram is a graph which shows under what conditions of temperature and pressure distinct phases of matter occur.
  • The simplest phase diagrams are of pure substances.
  • The major features of a phase diagram are phase boundaries and the triple point.
  • Phase boundaries, or lines of equilibrium, are boundaries that indicate the conditions under which two phases of matter can coexist at equilibrium.
  • In this phase diagram, which is typical of most substances, the solid lines represent the phase boundaries.

• Solid to Gas Phase Transition

  • Sublimation is the phase transition from the solid to the gaseous phase, without passing through an intermediate liquid phase.
  • Sublimation is the process of transformation directly from the solid phase to the gaseous phase, without passing through an intermediate liquid phase.
  • It is an endothermic phase transition that occurs at temperatures and pressures below a substance's triple point (the temperature and pressure at which all three phases coexist) in its phase diagram.
  • But at temperatures below that of the triple point, a decrease in pressure will result in a phase transition directly from the solid to the gaseous.
  • At temperatures and pressures below those of the triple point, a phase change between the solid and gas phases can take place.

• Phase-Contrast Microscopy

  • In phase-contrast microscopy, parallel beams of light are passed through objects of different densities.
  • A phase ring in condenser allows a cylinder of light to pass through it while still in phase.
  • Unaltered light hits the phase ring in the lens and is excluded.
  • Phase-contrast images have a characteristic grey background with light and dark features found across the sample.
  • One disadvantage of phase-contrast microscopy is halo formation called halo-light ring.

• The Evaporating Atmosphere

  • Within each phase, the properties are uniform but between the two phases properties differ.
  • Water in a closed jar with an air space over it forms a two phase system.
  • Even at equilibrium, molecules are constantly in motion and, once in a while, a molecule in the liquid phase gains enough kinetic energy to break away from the liquid phase and enter the gas phase.
  • The water vapor in it changes phases.
  • It is in a phase equilibrium.

• Definition

  • After being faced with a disorienting dilemma in phase 1, the learner steps through the remaining phases reflecting on his/her own experiences.
  • Phase 3, the learner experiences a critical assessment of assumption.
  • Phase 5, the learner explores options for new roles, relationships, and actions.
  • Phase 6, the learner plans a course of action.
  • In Phase 8, the learner provisionally will try out new roles.

• Interphase

  • In order for a cell to move from interphase into the mitotic phase, many internal and external conditions must be met.
  • The centrosome is duplicated during the S phase.
  • The cell cycle consists of interphase and the mitotic phase.
  • Interphase is followed by the mitotic phase.
  • During the mitotic phase, the duplicated chromosomes are segregated and distributed into daughter nuclei.

• Phases of relationship development

  • The length of phases and transitions between phases will vary due to cultural and/or social differences.
  • The awareness phase begins before any transactions actually occur.
  • During this phase, partners are locating, identifying and qualifying various prospects.
  • The exploration phase is considered the test for both parties.
  • The dissolution phase is the decision to end the partnership.

• Neural Responses to Food

  • There are three overlapping phases of gastric control: the cephalic phase, the gastric phase, and the intestinal phase.
  • The first phase of ingestion, called the cephalic phase, is controlled by the neural response to the stimulus provided by food.
  • The gastric phase begins once the food arrives in the stomach.
  • This phase consists of local, hormonal, and neural responses.
  • This phase controls the rate of gastric emptying.

• Phase Changes and Energy Conservation

  • A phase of a thermodynamic system and the states of matter have uniform physical properties.
  • The measurement of the external conditions at which the transformation occurs is termed the phase transition.
  • There are well-defined regions on these graphs that correspond to various phases of matter, so PT graphs are called phase diagrams .
  • Using the graph, if you know the pressure and temperature you can determine the phase of water.
  • The solid lines—boundaries between phases—indicate temperatures and pressures at which the phases coexist (that is, they exist together in ratios, depending on pressure and temperature).