Understanding Tissue Staining: Methods and Mechanisms

Tissue Staining: Methods and Mechanisms

Matching Dyes to Colors: According to their coloring:

  • Topographic: Provides an overall view of a fabric’s structure (e.g., H&E).
  • Cytological: Allows for intimate study of cells (e.g., Pap smears, panoptic cell structure).
  • Histochemical: Tries to highlight chemical substances or a determined chemical function (e.g., Perls, PAS highlight tissue structures, MSB Masson (collagenase), Orcein (TC), silver impregnation (reticulin)).

According to the coloring procedure:

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Understanding Atomic Properties: Radius, Ionization, and More

Understanding Atomic Properties

Atomic Radius

Atomic radius is half the distance between the nuclei of two identical atoms bonded together.

Ionization Energy

Ionization energy is the minimum energy required for a neutral atom of an element in a gaseous state and in its ground electronic state to yield an electron in its outer level and lead to a monopositive ion, also in a gaseous state and in its ground electronic state. Ionization energy increases upwards and to the right on the periodic table.

Electron

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Polymers: Types, Properties, and Applications

Polymers: Types, Properties, and Uses

A polymer is a macromolecule composed of long chains in repeated units known as monomers.

Classification of Polymers

According to their source:

  • Natural: Found in nature, formed by living things (e.g., proteins and cellulose).
  • Artificial: Obtained from natural polymers through chemical modification (e.g., celluloid).
  • Synthetic: Result from human design and manufacture (e.g., polyvinyl chloride or PVC).

According to their physical properties:

  • Elastomers: Possess high
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Fuel Types, Properties, Combustion, and Lubrication

Fuel Types

  • Solid
    • Natural
    • Artificial
  • Liquid
    • Alcohols
    • Waste
    • Derived from petroleum
  • Gaseous
    • Waste
    • Natural gas
    • Liquefied Gases
    • Artificial
    • Biogas

Properties of Fuels

  • Density: The amount of mass per unit volume, measured in kg/dm3.
  • Viscosity: The physical measurement of the resistance of a liquid to flow when an external force is applied.
  • Kinematic viscosity: The ratio of absolute viscosity and density, both measured at the same temperature.
  • Calorific Value (for liquid fuel): Indicates the amount of heat released when
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Understanding Heat, Temperature, and Thermodynamics

Venturi Tube and Thermodynamics

A Venturi tube is used to measure the velocity of liquids circulating inside a pressure pipe. It is also based on Bernoulli’s principle: when a liquid passes through this section, its pressure decreases, and its speed increases.

Thermodynamics is the part of physics that studies heat, and the difference between heat and temperature. Benjamin Thompson discovered that friction produces heat. Heat is the sum of all kinetic energy of the molecules. Temperature is a measure

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Ionic, Covalent, and Metallic Bonds: Properties

Ionic Bonds

Ionic bond: A transfer of electrons between a metal and a nonmetal, both achieving a stable configuration. It consists of the union of atoms with opposite electrical charges, held together by forces of electrostatic attraction. This attraction occurs in three dimensions, forming a compact, three-dimensional, neutral lattice of alternating cations and anions.

Properties of Ionic Compounds

  • Solid substances at room temperature, existing in a crystal lattice.
  • Very high melting and boiling points,
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