Philosophy

Philosophy can be defined as a form of knowledge that, despite the wide variety of its expressions, exhibits as almost constant characteristics two vocations: one towards universality and one towards the prescription of wisdom. The former manifests itself in two ways: philosophy is presented as the perfect form of knowledge, in any case as the …

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Arabic philosophy

One can speak of Arabic philosophy with regard to historical phenomena that occurred in different cultural and religious spheres, which also differed according to the historical period and the geographical area in which they were located, but which are basically united by the use of the same language: Arabic. The term includes both the so-called …

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Disgust

Ekman (1992) defines the emotion of disgust as “experiencing a feeling that motivates, organizes, and guides the perception of thoughts and actions.” In the course of evolution, in fact, emotions have developed to provide new types of motivation and incentive for action to meet the demands of the external environment. In addition, the emotion (in …

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Honey bee

Honey bees are mostly grouped in a genus Apis. However within the family ‘Apinae’ are stingless bees, part of the Meliponini tribe. These bees are different from honey bees producing less abundant but more liquid-based honey. This type of honey, produced by stingless honey bees, is traditionally used more for medicinal purposes. Classification of honey …

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Geometry

Geometry began as a systematic study of physical space and the shapes that move in it. The space in which we move is for everyone one of the first experiences we have from the first months of life. Our senses determine the sensations that allow us to recognize the shapes of objects and their movements. …

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Mathematics

Mathematics (from the Greek μάθημα (máthema), which can be translated as “science”, “knowledge”, or “learning”; μαθηματικός (mathematikós) means “inclined to learn”) is the discipline that studies quantities, numbers, space, structures, and calculations. The term mathematics usually refers to the discipline (and its body of knowledge) that studies problems involving quantities, spatial extensions and figures, movements …

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Neurologist

The neurologist is the physician who specializes in the diagnosis, treatment, and management of diseases and injuries involving the nervous system. The neurologist has many skills: he/she is highly trained in the anatomy and physiology of the nervous system; he/she knows the diseases of the nervous system, the methods of investigation to diagnose them and …

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Electromyography

Electromyography (EMG), electroneurography (ENG) and single fiber electromyography (SFEMG) are neurophysiological methods that are used to study the peripheral nervous system (PNS) from a functional point of view. It represents a reliable method that can give information about the functionality of peripheral nerves and skeletal muscles. It is also a diagnostic tool that allows to …

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Drift

In metrology, drift can be defined as the variation caused in the output of an instrument, which is not caused by any change in the input. Drift in a measuring instrument is mainly caused by internal temperature variations and lack of component stability. It also represents a static characteristic of an instrument. A change in the zero output of …

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Accelerometer

An accelerometer is a measuring instrument able of detecting and/or measuring acceleration (or the gravitational force), calculating the force measured with respect to the mass of the object (force per unit of mass). Therefore the operating principle of an accelerometer is based on the detection of the inertia of a mass when it is subjected to an …

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Gravimeter

The gravimeter is a particular type of accelerometer specifically designed to measure the acceleration of gravity. According to the equivalence principle of general relativity, the effects of gravity and acceleration are the same; therefore, an accelerometer cannot distinguish between the two cases. As gravimeters, it is possible to use improved versions of accelerometers for static measurements, in …

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Error band

The error band is a worst-case error measurement. This is the best specification (with respect to linearity) for determining the suitability of the measuring device for an application. The range of maximum deviation of the transducer output from a reference curve due to the transducer is defined as error band; said deviation (which is generally expressed …

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Rapidity error

In metrology, the error of rapidity is that metrological quality of a measuring instrument that expresses the ability to follow the (dynamic) variations in the time of the measurand; it is essential because it allows evaluating the limits within which a measuring instrument can be suitable for measuring variable quantities over time (dynamic quantities). Another practical definition …

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Insertion error

In metrology, the insertion error is caused by the presence of the measuring instrument itself, inside the environment in which the measurement is carried out; in other words, the measuring instrument changes the measurement conditions and consequently also changes the final value of the measurand. Therefore it is said that a measuring instrument is the better, the …

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Dynamic error

A dynamic error is a difference between the true value of the quantity changing with time and the value indicated by the measurement system if no static error is assumed. This error may have an amplitude and usually a frequency related to the environmental influences and the parameters of the system itself. In metrology, dynamic errors are caused by …

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Zero error

In metrology, zero error means the error that is made when long-term measurements are made, and it is verified that the zero of the measuring instrument undergoes a drift phenomenon, called zero drift. The zero error is evaluated in units of the quantity to be measured.

Mobility error

In metrology, more specifically, in the theory of measurement errors, the mobility error is mainly due to the friction that develops between the mobile components of the measurement instrument and the inevitable spaces between them.

Reading error

In metrology, the reading error is that what happens when evaluating the relative position of the index of the measuring instrument with respect to the scale; this error is generally due to four causes: resolving power of the human eye: it is defined as the angle of minimum separation between two points that the eye is able …

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Static error

Static errors are those errors evaluated in static conditions, that is, by performing the measurement of a constant physical quantity; they are: Reading error Mobility error Hysteresis error Fidelity error Zero error Calibration error

Gross error

Gross errors are those attributable to inexperience or distraction of the operator who is making the measurement; may for example result from a wrong reading or by improper use of measuring instruments, or by incorrect transcriptions from experimental data or even erroneous processing of such data. These errors do not occur when measurements are taken with …

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Random error

Random error is always present in a measurement. It is caused by inherently unpredictable fluctuations in the readings of a measurement instrument, in operating and environmental conditions or the experimenter’s interpretation of the instrumental reading. Random errors can be analyzed statistically, as it is empirically seen that they are generally distributed according to simple laws. In …

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Hydraulics

Hydraulics is the science that studies the motion and use of liquids, particularly water; in fact, the word “hydraulic” comes from the Greek word ὑδραυλικός (hydraulikos) derived from ὕδραυλος meaning “hydraulo”, composed of ὑδρ- (hydr-) which is a contraction of ὕδωρ (hydor) meaning “water”, and αυλός (aulos) meaning “pipe”. The theoretical basis of hydraulics is …

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Heat sink

A heat sink, in electronics, is a metallic mechanical element of good thermal conductivity and equipped with fins, used in electronic circuits to obtain a good thermal dissipation by natural or forced convection. Heat sinks are usually used to promote heat dissipation from the collector of power transistors or anti-inductive loads used to measure the …

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Governance

Governance is how society or groups within it, organize to make decisions; it comprises all of the processes of governing. The concept of governance has been around in both political and academic discourse for a long time, referring in a generic sense to the task of running a government, or any other appropriate entity for …

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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 the mechanical parts from corrosive …

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Friction

Friction can be defined as the force between surfaces in contact that resists their relative tangential motion (slipping). Friction is a passive resistance that tends to hinder the relative motion of two bodies in contact. Passive resistance, which produces the loss of dynamic work in contact between bodies in relative motion, can be distinguished in various …

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Geography

Geography (from the Latin geographia, in turn from the ancient Greek: γῆ, “earth” and γραφία, “description, writing”) is the science that has as its object the study, description and representation of the Earth in the configuration of its surface and in the extension and distribution of physical, biological, human phenomena that affect it and that, …

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War

War is a social phenomenon that has its distinctive feature in the armed violence between organized groups. In its traditional meaning, war is a conflict between sovereign states or coalitions for the resolution, usually as a last resort, of an international dispute more or less directly motivated by real or presumed, but in any case …

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Non-renewable resource

Non-renewable resource (called also non-renewable energies) are energy sources that tend to run out over time and therefore the environmental impact associated with their exploitation is generally more significant than that of renewable energy sources, which are instead reintegrated naturally in a relatively short period. Non-renewable energy sources are often exploited by humanity because they …

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Energy harvesting

Energy harvesting (also known as power harvesting or energy scavenging or ambient power) is a method of generating electrical energy from normally unused energy sources available in the surrounding environment. In other words, it is the process by which energy, coming from alternative energy sources (commonly available in the environment: thermal energy, kinetic energy, chemical energy, …

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Thermal energy

It is called thermal energy that type of energy that anybody has at a temperature above zero. This condition represents an extensive quantity and is directly proportional to the temperature that the body generates. Thermal energy is the kinetic energy of the microscopic motion of particles, a form of a disordered equivalent of mechanical energy; …

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Soundwave energy

Soundwave energy is kinetic, and potential energy through a transmission medium (such as a gas, liquid, or solid) due to a sound propagated a wave of pressure (a particular form of a mechanical wave). The sound is transmitted through gases, plasma, and liquids as longitudinal waves also called compression waves. It requires a medium to propagate. Through solids, however, it can be transmitted as …

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Rest energy

The rest energy E0 of a particle is defined as E0 = m0c2 where “c” is the speed of light in vacuum. In general, only differences in energy have physical significance. The concept of rest energy follows from the special theory of relativity that leads to Einstein’s famous conclusion about the equivalence of energy and mass. On the other …

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Radiant energy

Radiant energy is the potential energy stored in the propagating fields of electromagnetic radiation (such as light, X-rays, gamma rays, and thermal radiation) that can be described in terms of discrete packets of energy, called photons, or continuous electromagnetic energy waves. The term “radiant energy” is most commonly used in the fields of radiometry, solar …

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Quantum chromodynamics binding energy

Quantum chromodynamics binding energy (QCD binding energy), gluon binding energy or chromodynamic binding energy is the energy binding quarks together into hadrons. It is the energy of the field of the strong force, which is mediated by gluons. QCD binding energy contributes most of the hadron’s mass. Most of the mass of hadrons is actually QCD binding energy, …

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Wind wave energy

Wind waves energy has a certain amount of randomness: subsequent waves differ in height, duration, and shape with limited predictability. They can be described as a stochastic process, in combination with the physics governing their generation, growth, propagation, and decay—as well as regulating the interdependence between flow quantities such as the water surface movements, flow velocities, and …

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Elastic energy

Elastic energy is potential energy related to elastic force, stored in the deformation of a material (compression or stretching) or a physical system (distortion of volume or shape) exhibiting a restorative force. This also means that elastic potential energy is zero in objects that have not been stretched or compressed. The elastic potential energy equation is …

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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 …

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Acoustic wave [sound wave]

Acoustic waves (also known as sound waves) are a type of longitudinal waves that propagate by means of adiabatic compression and decompression. Longitudinal sound waves are waves that have the same direction of vibration as their direction of travel. Important quantities for describing acoustic waves are sound pressure, particle velocity, particle displacement, and sound intensity. Acoustic waves …

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Mechanical wave energy

Mechanical wave energy is kinetic and potential energy in an elastic material (medium) due to a propagated deformational wave (oscillation of matter). Mechanical waves transport energy. This energy propagates in the same direction as the wave. Examples: ocean wind-generated waves, sound waves, seismic waves. Any kind of wave (mechanical or electromagnetic) has a certain energy. Mechanical …

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Mechanical energy

Mechanical energy is the sum of macroscopic translational and rotational kinetic and potential energies. Mechanical energy is the energy that is possessed by an object due to its motion or due to its position; can be either kinetic energy (energy of motion) or potential energy (stored energy of position). \[E_{m-tot}=K+P\] Objects have mechanical energy if they are …

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Magnetic energy

Magnetic energy is the potential energy due to or stored in magnetic fields. Magnetic energy and electric energy are related to Maxwell’s equations. In fact, thanks to Maxwell’s work, magnetic and electric energy are more appropriately considered as a single force. Together, they are what is known as electromagnetic energy (a form of energy that has …

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Gravitational energy

Gravitational energy is the potential energy a body with mass has in relation to another massive object due to gravity. It is the potential energy associated with the gravitational field. Gravitational energy is dependent on the masses of two bodies, their distance apart, and the gravitational constant G. The general expression for gravitational potential energy arises from the law of …

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Electric energy

Electric energy is the energy newly derived from electric potential energy or kinetic energy due to or stored in charged particles within an electric field. When loosely used to describe energy absorbed or delivered by an electrical circuit (for example, one provided by an electric power utility) “electrical energy” talks about energy which has been converted …

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Dark energy

Dark energy is a form of energy that exerts a negative, repulsive pressure, behaving like the opposite of gravity. It has been hypothesised to account for the observational properties of distant type Ia supernovae, which show the universe going through an accelerated period of expansion. Like dark matter, dark energy is not directly observed, but …

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Chemical energy

Chemical energy is the potential energy stored in the bonds of chemical compounds to undergo a transformation through a chemical reaction to transform other chemical substances. It varies due to the formation or breaking of chemical bonds of any kind in the chemical elements involved in chemical reactions. An example of chemical potential energy is the …

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Binary star

A binary star is defined as a star system formed by two stars orbiting around their common center of mass; the brighter star is called primary, while the other is called companion or secondary. The observations made since the nineteenth century suggest that there are many stars that are part of binary systems or multiple …

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Star

A star is a celestial body that shines with its own light. It is a plasma spheroid that through nuclear fusion processes in its core generates energy, radiated into space in the form of electromagnetic radiation (luminosity), elementary particle flux (stellar wind) and neutrinos. Much of the chemical elements heavier than hydrogen and helium are …

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Anthropology

Anthropology (from greek ἄνθρωπος ànthropos “man” and λόγος, lògos “speech, doctrine” then literally: “study of man”) is a scientific branch developed especially in the modern era that studies the human being from different perspectives (social, cultural, morphological, psycho-evolutionary, sociological, artistic-expressive, philosophical-religious), investigating its various behaviors within society; born as a discipline within biology, has later …

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Visual anthropology

Visual anthropology is a field of applied cultural anthropology that studies and documents the visual manifestations of human behavior, processing data collected not only in ceremonies and customs but also in the myths, attitudes, and dreams of individuals and groups to which they belong. The investigations conducted among homogeneous groups, social classes and ethnic groups …

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Stomach

The stomach (in ancient Greek στόμαχος, stòmachos, from which the lat. stomachus; in Latin also ventriculus) is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach is the organ that receives from the esophagus the food introduced through the mouth. Inside the stomach the digestive …

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Calibration

Calibration is the procedure used to establish a relationship between the values of measurement values delivered indicated by the measuring instrument and the corresponding values realized by standards of known accuracy under specified conditions. “Calibration” is an operation, performed under specified conditions, which in a first step establishes a relationship between the values of a quantity, …

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Parallax

Parallax is a deceptive change in the relative position of an object with a change in the position of the observer. Due to foreshortening, nearby objects show a larger parallax than farther objects when observed from different positions, so parallax can be used to determine distances. By measuring the parallax angle and the distance between the …

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Transducer

A transducer is defined as a technological device capable of switching (transforming, transducing) the nature of the physical quantity detected (object of measurement) by the sensor into a signal that is more easily intelligible and processed by the subsequent stages of the measurement chain. In other words, a transducer is able to provide an output, …

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Sensor

In Metrology, a sensor is a sensitive device placed in contact with the physical quantity, the object of measurement, that is, it represents the element compatible and capable of collecting information from the physical quantity in the measuring environment. In other words, a sensor is defined as an instrument, or a part of a measuring system, capable …

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Measuring instrument

A device used for the measurement of a certain physical quantity is called a measuring instrument. The instruments indicate the value of these quantities, based on which we get some understanding and also take appropriate actions and decisions. Types of measurement instruments There are two main types of measuring instruments: analog and digital. The analog instruments indicate the magnitude of …

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Hysteresis

Hysteresis is a phenomenon whereby the value assumed by a quantity dependent on others is determined not only by the instantaneous values of the latter, but also by the values they had assumed previously; in other words, hysteresis is the characteristic of a system to react in delay to applied stresses and in dependence on …

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Measurement

In metrology the term measurement is closely associated with all the activities about scientific, industrial, commercial, and human aspects. It is defined as the assignment of a number to a characteristic of an object or event, which can be compared with other objects or events. The knowledge of the reality that surrounds us is based on the …

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Painting

The term painting refers to the art of graphically depicting and representing something (such as a material object, a landscape, an abstract figment of the imagination) by means of lines, colors, masses, values, and tones on a mostly two-dimensional surface. By extension: a pictorial trend that is distinguished by style, author, country, era, or otherwise. …

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Romanticism

The difficulty experienced in reaching a definition for romanticism that embraces both its complex development and regional particularities seems insoluble. Romanticism can be understood primarily as the acceptance and, finally, the exaltation of those elements that are characteristic of human consciousness and behavior: melancholy, irrationality, doubt, individual eccentricity, excessive egocentricity, despair, dissatisfaction with the repetitive …

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Pointillisme [pointillism]

Pointillisme (pointillism) was a pictorial current that emerged around 1885, baptized Neo-Impressionism by the critic F. Fénéon in 1886, the year in which G. Seurat presented La Grande-Jatte (Chicago, Art Institute) at the Salon des Indépendants. An article entitled Neo-Impressionism, in which the technical procedures and aesthetics of the movement were exposed, was also published …

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Les Nabis

Les Nabis is a pictorial movement that arose in France in the late nineteenth century by a group of young artists, all born between 1860 and 1870: Maurice Denis (1870-1943), Pierre Bonnard (1867-1947), Edouard Vuillard (1868-1940), Aristide Maillol, Felix Vallotton, Paul-Elie Ranson (1861-1909), Jan Verkade, Ker Xavier Roussel, G. Lacombe. The term, chosen by the …

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Mir iskusstva

Mir iskusstva (Russian: «Мир искусства», IPA: [ˈmʲir ɪˈskustvə], World of Art) is an artistic movement founded in 1890 by a group of Russian intellectuals led by Sergei Diaghilev. The members of the group were scholars, art lovers, educated and refined, from a social background far removed from that of the Peredvizhniki, whose members came largely …

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Futurism

Futurism (from Italian: Futurismo) was an Italian literary, cultural, artistic and musical movement of the early 20th century, and one of the first European avant-garde movements. It had influence on related movements that developed in other countries of Europe, Russia, France, the United States of America and Asia. The Futurists explored all forms of expression: …

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Divisionism

Divisionism is an Italian painting movement that developed between 1885 and 1915; it was essentially born from Impressionism and further developed its research on the decomposition of colors and light. Spread in several parts of Italy but with the main artistic center in Milan, was officially born in 1891, when the first pointillist works (and …

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Art Nouveau

The Art nouveau style took on different names in the various countries where it spread: in Italy floral or liberty style (from the English warehouses of A. Lasenby Liberty, which sold Art nouveau objects); in Germany Jugendstil, in Austria Sezessionstil, in Spain modernism, while Art nouveau is the name it took on in France and …

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Realism

In Art, Realism is a pictorial artistic current that can be defined as the attempt to represent matter truthfully, without artifice and avoiding speculative fiction and supernatural elements; it developed in the 1840s and, in France, sees in Gustave Courbet its main exponent; the figures of Honoré Daumier and Jean-François Millet, as well as Rosa …

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Expressionism

Expressionism is an avant-garde artistic and literary movement, which has developed in Germany between the end of the 19th century and about 1925; in an uncomfortable and turbulent atmosphere that preceded the war of 1914; from a pictorial point of view, it appeared as a clear reaction to Impressionism, whose objectivity and scientific optimism were …

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Measurand

The measurand is defined as a physical quantity to be measured (such as length, weight, and angle). The specification of a measurand requires: the knowledge of the species of physical quantity; the description of the state of the phenomenon, of the body or of the substance of which the physical quantity constitutes a property (including all the …

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Measuring lag

The delay in the response of a measuring instrument to a change in the measured quantity is known as measuring lag. Thus it is the retardation delay in the response of a measurement system to changes in the measured quantity. This lag is usually quite small, but this small lag becomes highly important when high-speed measurements …

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Attention

Attention is a cognitive process that allows to select some environmental stimuli, ignoring others. From an evolutionary point of view, it is an extremely useful mechanism for human survival because it allows us to organize the information coming from the external environment, which is constantly changing, and to regulate mental processes accordingly. Attention refers to …

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Modern physics

Modern physics is defined as the set of theoretical and experimental scientific developments since the twentieth century, have marked a conceptual leap from classical physics, developed since the seventeenth century, to explain phenomena that were not describable with a “classical” approach (quantum mechanics, theory of relativity). It is not possible to indicate with precision a …

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Applied physics

The research area of applied physics brings together many expertise, groups, and application areas. Experimental activity focuses primarily on research and development of advanced methods and technologies, targeting both new experimental approaches to fundamental investigation and applications. The activity of the area can be divided into four main parts: use of diagnostic tools for the …

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Atomic physics

Atomic physics is the branch of modern physics that studies the properties of atoms as isolated systems, including electrons and atomic nuclei, mainly concerning the arrangement of electrons around the nucleus and the processes by which these arrangements change. This is a field of physics studied at the beginning of XX century with the provision …

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Condensed matter physics

Condensed matter physics is the branch of modern physics that studies the microscopic physical properties of matter. The virtually infinite rearrangements of matter, combined with micro/nano-structuring, continue to pose new research challenges for the development of novel compounds and materials characterized by controllable properties of both fundamental and applied interest. Condensed matter physics is concerned …

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Nuclear physics

Nuclear physics is the branch of physics that studies the atomic nucleus, its constituents, protons and neutrons, and their interactions; its objective is the study of nuclear phenomena, of the elementary constituents of the universe and their interactions. The complexity of experiments on one side and the refinement of research methodologies on the other side …

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Elementary particle physics

Elementary Particle Physics, also known as “high energy physics”, studies the fundamental constituents of matter, the so-called elementary particles, and their interactions through experiments using increasingly powerful accelerator machines. For the known mass-energy equivalence (E = mc2), to have higher and higher energy means that it is possible to “create” particles of higher and higher …

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