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  2. Periodic trends - Wikipedia

    en.wikipedia.org/wiki/Periodic_trends

    In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863.

  3. Maintenance philosophy - Wikipedia

    en.wikipedia.org/wiki/Maintenance_philosophy

    The procedures associated with periodic maintenance are generally called a Periodic Maintenance System (PMS). There is risk that the system will not work as expected, and this risk grows as time passes due to increasing possibility of silent faults that cause operational failure. Periodic maintenance actions control risk of operational failure.

  4. Maintenance - Wikipedia

    en.wikipedia.org/wiki/Maintenance

    Planned preventive maintenance (PPM), more commonly referred to as simply planned maintenance (PM) or scheduled maintenance, is any variety of scheduled maintenance to an object or item of equipment. Specifically, planned maintenance is a scheduled service visit carried out by a competent and suitable agent, to ensure that an item of equipment ...

  5. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  6. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    Like the periodic table, the list below organizes the elements by the number of protons in their atoms; it can also be organized by other properties, such as atomic weight, density, and electronegativity. For more detailed information about the origins of element names, see List of chemical element name etymologies.

  7. Predictive maintenance - Wikipedia

    en.wikipedia.org/wiki/Predictive_maintenance

    Predictive maintenance evaluates the condition of equipment by performing periodic (offline) or continuous (online) equipment condition monitoring.The ultimate goal of the approach is to perform maintenance at a scheduled point in time when the maintenance activity is most cost-effective and before the equipment loses performance within a threshold.

  8. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    The periodic table, also known as the periodic table of the elements, is an ordered arrangement of the chemical elements into rows ("periods") and columns ("groups"). It is an icon of chemistry and is widely used in physics and other sciences.

  9. Outline of chemistry - Wikipedia

    en.wikipedia.org/wiki/Outline_of_chemistry

    The following outline acts as an overview of and topical guide to chemistry: . Chemistry is the science of atomic matter (matter that is composed of chemical elements), especially its chemical reactions, but also including its properties, structure, composition, behavior, and changes as they relate to the chemical reactions.