## Friction

Friction can be defined as the force between surfaces in contact that resists their relative tangential motion (slipping). One of the simpler characteristics of friction is that it is parallel to the contact surface between systems and always in a directionthat opposes motion or attempted motion of the systems relative to each other. If two systems…

## Plasticity

Plasticity is the capacity to resist plastic deformation (dislocation movement of a solid material undergoing non-reversible changes of shape in response to applied forces), while toughness measures the ability of a material to resist crack propagation. The rocks, subjected to external forces, are deformed continuously and permanently, without however being subjected to rupture phenomena and…

## Rheid

In geology, a rheid is a substance whose temperature is below the melting point and whose deformation by viscous flow during the time of observation is at least three orders of magnitude $$(10^3)$$ greater than the elastic deformation under the given conditions. A material is a rheid by virtue of the time of observation. The…

## Lubricant

A lubricant is an organic or synthetic substance (it can occur in any physical state: liquid, solid, gaseous and even semi-solid or viscous) which has the property of reducing the friction between surfaces in contact under any operating condition, dissipating the heat generated during the relative movement between the surfaces, maintaining its chemical stability, protecting…

## Force

The force may be thought of as an influence which tends to change the motion of an object. Forces are inherently vector quantities, requiring vector addition to combine them. The SI unit for force is the newton [N], which is defined by Newton = $$\dfrac{kg\cdot m}{s^2}$$ as may be seen from Newton’s second law. In mechanics, forces are…

## Viscoelasticity

Viscoelasticity is the study of materials which have a time-dependent strain that exhibit both viscous and elastic characteristics when undergoing deformation. Viscoelastic response is often used as a probe in polymer science, since it is sensitive to the material’s chemistry and microstructure. The identification of the viscoelastic behavior is carried out by measuring the variation…

## Anelasticity

Anelasticity is a characteristic of viscoelastic materials that depends on some physical properties of the material itself. Anelasticity is the opposite of elasticity. An anelastic material subjected to stress undergoes deformations that are not proportional to the stresses and that do not disappear when the force is zeroed. In other words, an anelastic material will…

## Elasticity

Elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate forces are applied to them. If the material is elastic, the object will return to its initial shape and size when…

## Reasoning methods

Abductive reasoning Abductive reasoning is a form of logical inference typically begins with an observation or an incomplete set of observations then seeks to find the simplest and most likely explanation. This process, unlike deductive reasoning, yields a plausible conclusion but does not positively verify it. Abductive conclusions are thus qualified as having a remnant of…

## Gear (cogwheel)

A gear (or cogwheel) it is the main element in a transmission system, in which teeth are cut around cylindrical or cone shaped surfaces with equal spacing; or in the case of a cogwheel, inserted teeth (called cogs). By meshing a pair of these elements, they are used to transmit rotations and forces from the…

## Semiconductor

A semiconductor is a substance with an electrical conductivity between that of a conductor and an insulator — the conductivity of a semiconductor increases as temperature increases. Adding appropriate impurities also increases conductivity. Amorphous semiconductor An amorphous semiconductor also called “thin film” is a non-crystalline semiconductor material that has no long-range order. Although easier and…

## Wave

A wave is a perturbation that propagates in space and which can transport energy from one point to another. This perturbation consists of the variation of any physical quantity (for example pressure variation, temperature, electric field strength, position, etc.). Many natural phenomena are described in terms of waves. The waves in the water are together the prototype…

## Ant

Ants are the most numerous type of animal on Earth; their combined weight is greater than the combined weight of human kind.

## Bee (Anthophila)

A bee is a member of any of the 20,000 species of insects belonging to the superfamily Apoidea in the order Hymenoptera. Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Hymenoptera Suborder: Apocrita Superfamily: Apoidea Clade: Anthophila The bee, emblem of industriousness, has been a symbolic insect in myths, legends, and religions since ancient times, certainly…

## Wasp

A wasp is any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. The Apocrita have a common evolutionary ancestor and form a clade; wasps as a group do not form a clade but are paraphyletic concerning bees and ants.

## Insect (insecta)

Insects or insecta (from Latin insectum) are the largest group in the animal kingdom (1 million insect species estimated on the planet).

## Pompilidae

Hymenoptera, Apocrita insect family; cosmopolitan. Pompilidae are commonly called spider wasps, spider-hunting wasps, or pompilid wasps. Up to 7 cm long, they have an enlarged head, large eyes, long antennae, an elongated abdomen, and reduced or missing wings; the females have a sting connected with poisonous glands, with which they paralyze spiders, on which they lay their eggs.

## Pompiloidea

Pompiloidea is a superfamily that includes at least five families in the order Hymenoptera; cosmopolitan. Mutillidae (velvet ants) Myrmosidae (myrmosid wasps) Pompilidae (spider wasps) Sapygidae (sapygid wasps) Burmusculidae (extinct) Kingdom Animalia Phylum Arthropoda Subphylum Hexapoda Class Insecta Order Hymenoptera Superfamily Pompiloidea

## Vespoidea

The Vespoidea are a superfamily of wasps in the order Hymenoptera, although older taxonomic schemes may vary in this categorization, particularly in their recognition of a now-obsolete superfamily Scolioidea, as well as the relationship to ants. Vespoidea includes wasps with a large variety of lifestyles; eusocial, social, and solitary habits, predators, scavengers, parasitoids, and some herbivores.

## Arthropod

Arthropods are any of the invertebrates with a hard shell and jointed legs. They are assigned to the taxonomic phylum Arthropoda, which is the largest phyla of animals on earth, comprising over 80% of the world’s known organisms with over a million modern species described. Their number is unknown but it is estimated that there are 1,097,289 described living arthropods.

## Apocrita

The apocrita are a suborder of hymenoptera insects, which includes the infraorder aculeata, that is the great majority of the hymenoptera. The terebrantia, or parasitica, is considered a second infra-order of apocrites; they are a paraphyletic group, therefore invalid.

## Animal (kingdom animalia)

Animals are any of the species of organisms that are assigned to the taxonomic Kingdom Animalia, which contains groups broadly categorized as invertebrates and vertebrates. The latter contains the familiar types such as mammals, amphibians, birds, fish, and reptiles. The former, however, consists of those with or without an exoskeleton like the insects, crustaceans, jellyfish, worms, etc.

## Electric circuit

An electric circuit is an unbroken loop of conductive material that allows electrons to flow through continuously without beginning or end. If a circuit is broken, that means it’s conductive elements no longer form a complete path, and continuous electron flow cannot occur in it. The location of a break in a circuit is irrelevant…

## Humidity

Humidity is the amount of water vapor in the air, measured as mass of water per unit volume or mass of air, or as a percentage of the maximum amount the air would support without condensation, or indirectly via the dew point. Saturation of the air occurs when the water vapor pressure reaches the vapor pressure…

## Buoyancy

Buoyancy or upthrust is an upward force exerted by a fluid that opposes the weight of an immersed object; it is what makes an object float, sink, or remain neutrally buoyant in the water (or other fluids). The symbol for the magnitude of buoyancy is $$B$$ or $$F_B$$. As a vector, it must be stated…

## Light

Luminous intensity (candela) The units of luminous intensity based on flame or incandescent filament standards in use in various countries before 1948 were replaced initially by the “new candle” based on the luminance of a Planck radiator (a black body) at the temperature of freezing platinum. This modification had been prepared by the International Commission…

## Electric current

Dynamic electricity, or electric current, is the uniform motion of electrons through a conductor. Static electricity is an unmoving, accumulated charge formed by either an excess or deficiency of electrons in an object. Although it is electrons which are the mobile charge carriers which are responsible for electric current in conductors, it has long been…

## Length

The length, quantitatively and objectively, identifies a material body according to a single main or prevalent dimension of the body itself. The measure of length leads to the knowledge of the geometry of bodies, that is to their “dimensions.” Many length measurements are also based on many (indirect) measurements of other physical quantities. Length measurements…