Ultrasonography is an imaging technique that uses the transmission of high-frequency sound waves into the body to generate an echo signal that is converted by a computer into a real-time image of anatomy and physiology. Ultrasonography is the least invasive of all imaging techniques, and it is therefore used more freely in sensitive situations such as […]
For sound insulation or soundproofing (or acoustic shielding) means all those actions aimed at limiting the unwanted sound and noise transmission, usually by introducing sound-absorbing materials in the path of the sound waves. The application fields where insulation or soundproofing measures are necessary are many, including recording studios, rehearsal rooms, cinemas, and environments dedicated to audio-video, residential, offices, and public places, industry,
A hydrophone (Ancient Greek: ὕδωρ + φωνή, lit. ’water + sound’) is a microphone designed to be used underwater for recording or listening to underwater sound. Most hydrophones consist of a piezoelectric transducer that translates mechanical energy resulting from a change in pressure into electrical energy. Some piezoelectric materials, or transducers, can convert a sound into an electrical
An airlock, air-lock or air lock, is a compartment with doors which can be sealed against pressure which permits the passage of people and objects between environments of differing pressure or atmospheric composition while minimizing the change of pressure in the adjoining spaces and mixing of environments. Airlocks find application in many fields, especially in:
The term “resistance” can take on different meanings depending on the context: Grammar Noun, countable and uncountable.Plural: resistances. Etymology From earlier resistence.From Middle English resistence.From Old French resistence.From Latin resistentia.Morphologically: resist + –ance. Pronunciation IPA: /ɹɪˈzɪstəns/ Synonyms – friction, obstacle;stubbornness, inflexibility, opposition, obstinacy, refractoriness, reluctance, tenacity;– (of what) firmness, consistency, durability, hardness, sturdiness, steadfastness, solidity;– (of character) constancy, firmness, perseverance, forbearance, tolerance;– (sports)
With balance of system (BOS) we mean a system of control and conditioning of the power of a photovoltaic or wind power plant. It expresses in percentage the energy losses that are in the plant due to various factors, such as: the coupling between the various photovoltaic modules, the connections with the converter(s), the losses in the
Tomography refers to imaging by sections. Computed tomography (CT scan) is a noninvasive imaging technique that uses computers to analyze several cross-sectional X-rays in order to reveal minute details about structures in the body. The technique was invented in the 1970s and is based on the principle that, as X-rays pass through the body, they are absorbed
Industrial biotechnology involves the use of living cells or their components for the production of goods and services aimed at greater environmental sustainability in industrial production systems. They present a rich range of applications and the number of sectors in which they can be used is increasingly wide. In particular, their use in the production
The perceptron is a device born from a first draft of artificial neuron theorized by Warren Mc Culloch and Walter Pitts and later taken up by Frank Rosenblatt, in 1958, who developed an electromechanical machine consisting of potentiometers, motors, and photocells that would have the purpose of recognizing simple geometric shapes. It consists of a “retina” made
Galvanization is an industrial chemical process of protection against corrosion (galvanic corrosion), in which a coating of zinc is applied to a metal item, hindering the formation of lettrolytic micro-cells with anodic action in the grain edges. Galvanization guarantees a long duration against atmospheric agents, without the need of periodical maintenance. The galvanized product at the
Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than
A laser optoelectronic device capable of emitting a coherent beam of light (a unidirectional, monochromatic radiation with a wavelength between infrared and ultraviolet) through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term “laser“ originated as an acronym for “light amplification by stimulated emission of radiation“. The first laser was built
In photometry, luminous flux (or luminous power) is a photometric quantity that measures the perceived power of light. The sensitivity of the human eye varies according to the wavelength of the light emitted. The luminous flux differs from the radiant flux, which is instead the measure of the total power of electromagnetic radiation emitted. The luminous flux
Tribotronics is a field of application of tribology that deals with integrating active control loops into machinery where tribological phenomena occur to improve the efficiency of the machinery itself. Tribotronics addresses questions like: “How should we design self-sensing bearings, that can detect their own wear and upcoming failure?”, or “How can we design seals that can
Electromagnetic compatibility (sometimes referred to by the acronym EMC), is a sub-discipline of electrical and electronic engineering, which deals with the analysis and optimization of unwanted effects produced by the unintentional generation, transmission and reception of electromagnetic energy, with the aim of ensuring the proper functioning in the same environment of various other electrical / electronic equipment
A heterostructure is a crystal composed of multiple semiconductors of different types. Generally these are in the form of more or less thin layers aligned one after the other in a direction called the growth direction. The interface between one layer and the next is called a heterojunction. Fabrication It is possible to realize very refined heterostructures,
Dehumidification is the process of removing humidity from a system. The dehumidification of aeriformes can be done purely physically or physicochemically. The dehumidification by physical means is obtained by subjecting the aeriform to cooling until it reaches saturation, after which further cooling causes the condensation of water and other vapors that may be present. A subsequent
Corrosion indicates a natural and irreversible process of slow and continuous consumption of a material, which has as its consequences the deterioration of the characteristics or physical properties of the material initially involved. Corrosion is a phenomenon of electrochemical nature that determines a chemical-physical interaction of the metallic material with the environment that surrounds it. Many
Radio waves, in physics, are electromagnetic radiations, belonging to the electromagnetic spectrum, in the frequency band between 3 kHz and 300 GHz, i.e. with a wavelength greater than 1 mm. At 300 GHz, the corresponding wavelength is 1 mm (shorter than a grain of rice); at 30 Hz the corresponding wavelength is 10,000 km (longer
An electric motor is an electromechanical energy conversion machine (i.e., capable of converting electrical energy into mechanical energy), consisting of a fixed part (stator) and a moving part (rotor or slider, depending on whether the machine is rotating or linear) separated by a small air gap of uniform thickness, called the air gap. Classification of electric motors
Tribology (from Greek Τρίβος “tribos”, friction, and λόγος “logos”, study or science) is the science that studies the behavior and interactions between surfaces that interact with each other with a relative motion. In it converge study topics included in different disciplines, such as friction phenomena, theory and technique of lubrication, study and use of lubricants, microscopic
Wear is defined as the removal of material from the surface of bodies in contact subject to relative motion. Wear affects the surfaces of contact members of machines causing a progressive decay of the functional characteristics. This phenomenon, however, has not only negative sides, on the contrary, it is often used to reduce the roughness of
Neuromorphic engineering, also known as neuromorphic computing, is a concept developed by Carver Mead, in the late 1980s, who spent over 40 years developing analysis systems designed to mimic the human senses and processing mechanisms of our bodies, such as touch, sight, hearing, and thought. Neuromorphic computing is a branch of neuromorphic engineering that focuses primarily
In electrical engineering is defined short circuit a connection between two points of an electrical circuit that has resistance close to zero, this imposes a voltage almost zero (or negligible) at its ends and does not impose constraints on the current flowing through it, which can take very high values. Ideal short circuit It is
The Peltier cell (also called Peltier device, Peltier heat pump, solid state refrigerator, or thermoelectric cooler (TEC) and occasionally a thermoelectric battery) is a thermoelectric device consisting of many Peltier effect junctions in series, used both as a cooling and heating device; they are reversible through the Seebeck effect and can also be adopted as generators (for example in solar panels). Peltier cells
