Glossary of the key notions in Bionics and beyond



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Debye-Hückel theory → A theory which allows us to calculate the mean ion activity coefficient for electrolytes and take into account non-ideality.

Decibel → It is a logarithmic unit that indicates the ratio of a physical quantity relative to a reference level.

Decoding algorithms → Computer algorithms that interpret neural signals for the purposes of understanding their function or for providing control signals to machines

Deconvolution → A mathematical operation in which the values from one function are removed from the values of another. In fMRI, where the signal is generally interpreted to be the result of a neuronal timeseries (which is modeled by the design matrix) convolved with a hemodynamic response function (which is modeled by a canonical HRF, basis functions, or a finite impulse response model), the operation is usually used to separate the contributions of those two functions.

Deep brain stimulation (DBS) → ~ is a neurosurgical treatment involving the implantation of a medical device called a battery-powered neurostimulator which sends electrical impulses to the target area of the brain.

Defibrillator → Defibrillation consists of delivering a therapeutic dose of electrical energy to the affected heart with a device called a defibrillator. This depolarizes a critical mass of the heart muscle, terminates the arrhythmia, and allows normal sinus rhythm to be reestablished by the body’s natural pacemaker, in the sinoatrial node of the heart.

Degenerate stationary states → In such a case, when we have more than one essentially different eigenfunctions which correspond to the same eigenvalue, we call this eigenvalue and the corresponding stationary state - degenerate. If there corresponds only one eigenfunction to an eigenvalue, this eigenvalue is called nondegenerate.

Degradation of purines → During degradation of AMP and GMP xanthine and finally uric acid is formed. Because of its low solunility it is deposited in the joint tissue and kidney resulting in gout and kidney stone. The disease can be treated by the inhibitor of xanthine oxidase.

Degrading model → Degrading models are used for interpolating non measured situations

Degree of freedom → The number of independent generalized coordinates (independent displacements and/or rotations) is defined by the number of degrees of freedom of the system.

De-inactivation → ~ is a process of the opening of gates by membrane hyperpolarization in a voltage-gated ion channel (the opposite of inactivation).

Delayed rectifier → A slowly inactivating or non-inactivating potassium channel (conductance) which activates with a delay after a depolarizing voltage step.

Delta EEG band → EEG waves with frequency lower than 4 Hz.

Delta-Sigma AD converters → It oversamples the desired signal by a large factor and filters the desired signal band.

Density of states → The number of microstates attaining a given macrostate.

Dependent BCI → Some BCIs may rely on gaze shifting. Users may have to shift their eyes to use the BCI effectively, even though the signal still comes directly from the brain.

Deposition → ~ is the building up of material on the wafer surface.

Deprez-instrument → The ~ is an analog voltmeter, in which the index displacement is proportional to the flowing current.

Depth electroencephalography → Depth EEG is used when the brain waves are recorded by electrodes inserted within the brain substance itself.

DEPT-NMR → DEPT-NMR is an NMR method to determine the number of hydrogens attached to each carbon atoms. It can distinguish among signals due to CH3, CH2, CH and quaternary carbons.

Derivation → The term used for the combination of electrodes connected to input 1 and 2 of the differential amplifier.

Descartes → René Descartes (1596–1650) (Renatus Cartesius) was a French philosopher and writer. He has been dubbed the ‘Father of Modern Philosophy’, and much subsequent Western philosophy is a response to his writings.

Descartes coordinates → It is an analytical tool of algebra and geometry by providing a way to visualize functions. Descartes introduced the coordinate system that bears his name, the Cartesian coordinate system, which is based on a set of axes perpendicular to each other, corresponding to two variables respectively.

Descriptor → Standard parts of the database annotation that are typically included in distinct fields of the database record

Deshielding → ~ is an effect can be observed in NMR that causes a nucleus to absorb toward the left (downfield) side of the chart. It is caused by the withdrawal of electron density from the nucleus.

Design matrix → In fMRI implementation of the general linear model, the specification of how the model factors change over time.

Desynchronization → The term used to describe the change from synchronized EEG to a low amplitude usually higher frequency irregular EEG activity.

Detector → ~ is a device for detecting the presence of electromagnetic field.

DFT method → DFT (Density Functional Theory) is a quantum mechanical theory models used in physics and chemistry to investigate the electronic structure (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function, which in this case is the spatially dependent electron density. Hence the name density functional theory comes from the use of functionals of the electron density.

Diade → An outer product of a vector with itself. Note a diade has rank 1

Diamagnetic → A substance that will slightly decrease a magnetic field when placed within it (its magnetization is oppositely directed to the magnetic field, i.e., with a small negative magnetic susceptibility).

Diamond → ~ (Greek αδάμας/unbreakable) is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite. Diamond’s superlative physical qualities originate from the strong covalent bonding between its atoms. Diamond has the highest hardness and thermal conductivity of any bulk material.

Diastereomers → Compounds with the same constitution but not with enantiomeric relationship (not mirror-images of each other).

Diastereotopic group → ~ is a substitution with a new achiral (or chiral) group gives a pair of diastereomers.

Diazines → Diazine refers to a group of organic compounds having the molecular formula C4H4N2. Each contains a benzene ring in which two of the C-H fragments have been replaced by isolobal nitrogen. There are three isomers:

  • pyrazine (1,4-diazine)

  • pyrimidine (1,3-diazine)

  • pyridazine (1,2-diazine)

Dicke → Robert Henry Dicke (1916–1997) was an American physicist.

Die → A single piece of IC without packaging.

Die stacking → The simplest option for 3D integration is stacking of successively smaller dies.

Diels–Alder reaction → The ~ is an organic chemical reaction (specifically, a cycloaddition) between a conjugated diene and a substituted alkene, commonly termed the dienophile, to form a substituted cyclohexene system.

Diencephalon → Part of the brain developing from the prosencephalon, it provides the thalamus and the hypothalamus as major constituents

Differential amplifier → A ~ amplifies the potential difference between its two inputs suppressing the noise identical in the two input..

Differential equations → A differential equation is any equation for an unknown function of one or several variables that relates the values of the function itself and its derivatives of various orders. The order of a differential equation is the largest derivative present in the differential equation.

Diffusion → ~ describes the spread of particles through random motion from regions of higher concentration to regions of lower concentration.

Diffusion → ~ describes the spread of particles through random motion from regions of higher concentration to regions of lower concentration.

Diffusion (transmembrane) → Some hydrophobic and small molecules are able to pass across the membrane without the help of any protein or other specific structures.

Diffusion controlled reaction → A reaction where the rate of the diffusion determine the rate of the overall reaction. Reactions with low activation energy are usually diffusion controlled.

Diffusion flux → The rate of movement of molecules across a unit area

Digestion → Enzymatic degradation of dietary constituents to gain small products suitable for absorption

Digital Signal Processing/Processor (DSP) → It refers to various techniques for improving the accuracy and reliability of digital communications.

Digital subtraction angiography (DSA) → DSA is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a ‘pre-contrast image’ or the mask from later images, once the contrast medium has been introduced into a structure. Hence the term ‘digital subtraction angiography’.

Digital voltmeter → A ~ is an instrument used for measuring the electrical potential difference between two points in an electric circuit and give a numerical display of voltage by use of an analog to digital converter

Dihedral angle → the angle between two planes (usually of 4 successive atoms in a molecule)

Dimethyl sulfoxide (DMSO) → ~ is the organosulfur compound with the formula (CH3)2SO. This colorless liquid is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water.

Dipolar compounds → ~ are electrically neutral molecules carrying a positive and a negative charge in one of their major canonical descriptions. In most ~ the charges are delocalized; however the term is also applied to species where this is not the case.

Dipolar interactions → ~ is an interaction between molecules with permanent electric dipole moments. The combination of these molecules results in charge-separated structures.

Dipole → A pair of electric charges of equal magnitude but opposite sign.

Dipole moment → ~ is a vector quantity, the vector product of which with the electric field strength, E, of a homogeneous field is equal to the torque. T = p × E. The direction of the ~ is from the negative to the positive charge.

Dirac → Paul Adrien Maurice Dirac (1902–1984) was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics.

Dirac delta function → The ~, or δ function, is a generalized function depending on a real parameter such that it is zero for all values of the parameter except when the parameter is zero, and its integral over the parameter from −infinity to +infinity is equal to one. Informally, it is a function, which takes up the value 1 at specified points, and it is 0 elsewhere.

Dirac formalism → The ~ was introduced in order to describe in a uniform manner vectors and linear operators both in the abstract Hilbert space of the state vectors, and in the extensions of it which are used to solve the eigenvector problem for observables with discrete and continuous spectrum. It is a general and abstract formulation of quantum mechanics, which includes wave mechanics and matrix mechabics as special cases. A physical state is represented by a state vector in a complex linear vector space in N dimensions.

Direct addressing mode → It means a type of addressing when in the operand part of the instruction we do not find the address of the operand, but the operand itself. This dictates the biggest value of the operand (because of the restrictedness of the address part of the instruction), therefore it can be applied primarily with operations with small value constants.

Direct current → A constant electron flow from the negative to the positive electrode with constant polarity

Direct kinematics → To compute the position and velocity of the endpoint of the given limb as a functions of joint angles, angular velocities and limb segment lengths

Directed Acyclic Graph (DAG) → A graph in which the vertices are directed and which contains no cycle.

Disaccharides → Hydrolysis of disaccharides yields 2 molecules of monosaccharides

Discrete Cosine Transform (DCT) → It is a real transform that transforms a sequence of real data points into its real spectrum and therefore avoids the problem of redundancy.

Discrete energy levels → A quantum mechanical system or particle that is bound (electrons in atoms or molecules) can only take on certain discrete values of energy. These discrete values are called energy levels.

Discrete Fourier Transform (DFT) → It transforms a discrete-time signal into discrete frequency samples.

Discrete spectrum → A ~ is an emission spectrum or absorption spectrum for which there is only an integer number (or countable number) of intensities.

Discrete time convolution → An elementary signal operation. For detail see the mathematical formula. A LTI system performs a convolution on it’s input and it’s impulse response function.

Discrete Time Fourier Transform (DTFT) → It is one of the specific forms of Fourier analysis in which input function is discrete.

Discrete time signal (DTS) → A sequence of numbers and corresponding time values for each sample

Disjunctive normal form → A function consisting of the OR connection of minterms, without OR. It is also customary to call it minterm form, the sum of products, or sum-product, or the sum of minterms.

Dispersion interaction → ~ is an interaction between uncharged molecules. These forces arises from the transient noncoincidence of the centers of negative and positive charge. These transient dipoles interact with similar transient dipoles in neighboring molecules.

Dissection → ~ is the process of disassembling and observing something to determine its internal structure and as an aid to discerning the functions and relationships of its components.

Dissipation → The loss of energy from a physical system, most often in the form of heat.

Distance matrix → Generated from an intensity matrix by concidering values for a gene as coordinates, and then computing distances between points corresponding to genes

Distance measures → Numerical measures defined to describe the similarity between objects. Distance between identical objects is zero but it is a large value between dissimilar objects.

Distillation → Heat the liquid to boiling, and after condensation of the vapor.

Distributiv law → Let denote tow operations by * and # respectively. If A#(B *C) = A#B *A#C then x is distributive with respect to *.

Disulfide bond → A covalent bond between two thiol group going with the oxidation of them.

Disulfides → Disulfide usually refers to the structural unit composed of a linked pair of sulfur atoms (disulfide bond).

Div → Divergence is a vector operator that measures the magnitude of a vector field’s source or sink at a given point, in terms of a signed scalar. It represents the volume density of the outward flux of a vector field from an infinitesimal volume around a given point.

Divergence → When signals collected by a larger number of neurons than the number of signal-producing neurons is.

Divide-and-conquer → It is an important algorithm design paradigm based on multi-branched recursion.

DNA (A1391DeoxyriboNucleic Acid) → A biopolymer (polynucleotide) that contains the genetic information of a living organism.

DNA chip or microarray → A miniature device that contains a dense grid of DNA elements on a support. It is suitable for detecting the presence or absence of DNA molecules in a sample that can hybridize to the DNA molecules on the chip.

DNA cloning → Isolation and amplification of a certain DNA molecule (e.g. gene) from an organism’s genome.

DNA sequencing → The laboratory process in which the nucleotide sequence of a DNA molecule is determined.

Domains → A quite independent structural, functional or folding unit of a protein.

Donnan equilibrium → The equilibrium characterized by an unequal distribution of diffusible ions between two ionic solutions separated by a membrane which is impermeable to at least one of the ionic species present, for example because they are too large to pass through the pores of the membrane.

Donnan potential → An electrical potential caused by an unequal distribution of ion species at the two sides of a selective boundary.

Donor atom → A donor is a dopant atom that, when added to a semiconductor, can form n-type regions. When an element, having four valence electrons (Si), needs to be doped as an n-type semiconductor, elements from group V (phosphorus or arsenic) can be used because they have five valence electrons. When substituting a Si atom in the crystal lattice, four of the valence electrons of phosphorus form covalent bonds with the neighbouring Si atoms but the fifth one remains weakly bonded. At room temperature all the fifth electrons are liberated, can move around the Si crystal and can carry a current, act as charge carriers. The initially neutral donor becomes positively charged (ionised).

Doping → The process of adding controlled impurities to a semiconductor is known as doping. Doping intentionally introduces impurities into an extremely pure (intrinsic) semiconductor for the purpose of modulating its electrical properties. The impurities are dependent upon the type of semiconductor.

Doppler shifts → The wavelength of electromagnetic signal emitted by a moving object is shifted.

Dorsal root → Fiber bundle of sensory afferents carrying information to the spinal segment

Dot plot analysis → A two-demensional matrix (aone sequence on each axes) with dots at points where the two sequences match

Double bond → ~ is a covalent bond formed when two atoms share two pairs of electrons.

Double gate FET → The distinguishing characteristic of the FinFET is that the conducting channel is wrapped around a thin silicon “fin”,

Double pendulum → A ~ is a pendulum with another pendulum attached to its end, and is a simple physical system that exhibits rich dynamic behavior with a strong sensitivity to initial conditions. The motion of a double pendulum is governed by a set of coupled ordinary differential equations.

Double TMS → Stimulation with two stimulation coils applied to different cerebral loci; the timing and stimulus intensity are adjusted separately.

Double-slit experiment → The ~ (Thomas Young’s experiment) involves particle beams or coherent waves passing through two closely-spaced slits, after which in many circumstances they are found to interfere with each other.

Down-quark → The ~ (d) is the second-lightest of all quarks, a type of elementary particle It is one of the constituents of the neutrons and protons of atomic nuclei. It has an electric charge of -13 e and a bare mass of 4.1–5.8 MeV/c2. It is an elementary fermion with spin -12, and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions.

Drift velocity → The ~ is the average velocity that a particle, such as an electron, attains due to an electric field. In general, an electron will ‘rattle around’ in a conductor at the Fermi velocity randomly. An applied electric field will give this random motion a small net velocity in one direction.

Driving point plot → The dp plot shows the local infelion points of the state transition rule

Drug delivery systems → A technology, or device for delivering drugs to a patient.

Drying (of liquids and solutions) → ~ is the removal of traces of water.

Duality → The wave particle ~ principle of quantum physics holds that matter and light exhibit the behaviors of both waves and particles, depending upon the circumstances of the experiment.

Dual-pulse (paired-pulse) TMS → Stimulation with two distinct stimuli through the same coil at a range of different intervals; the intensities can be varied independently.

Dual-slope converter → An ~ is a type of analog-to-digital converter that converts an unknown input voltage into a digital representation through the use of an integrator. The unknown input voltage is applied to the input of the integrator and allowed to ramp for a fixed time period (the run-up period). Then a known reference voltage of opposite polarity is applied to the integrator and is allowed to ramp until the integrator output returns to zero (the run-down period).

Duration → The ~ means the length of the signal (time value - horizontal axis) or a particalur time interval of the signal. For example the ~ of an action potential is around 1 ms.

Dushman → Saul Dushman (1883–1954) was a Russian-American physical chemist.

Dynamic (switching) power → Occurs when circuits change their logic state charging and discharging of output capacitor.

Dynamic capacity → Maximum number of orthogonal patterns, with the network steady points are dynamically stable

Dynamic programming (DP) → A solution that simplifies recursion by storing partial results and thus eliminating recalculation when values later are needed

Dynamic range → The ~ is the ratio between the largest and smallest values of a quantity (e.g. sound). Usually it is measured as a ratio or in decibel (dB). A normal hearing has a 120 dB dynamic range, a cochlear implant user has just 10-20 dB.

Dynamics → ~ (Greek δυναμικός ~ powerful) may refer to the time evolution of physical processes.

Dynamo → A ~ (Greek word dynamis ~ power), originally another name for an electrical generator, generally means a generator that produces direct current with the use of a commutator.

Dynode → A ~ is one of a series of electrodes within a photomultiplier tube. Each ~ is at a more positive electrical potential than its predecessor. Secondary emission occurs at the surface of each dynode. Such an arrangement is able to amplify the tiny current emitted by the photocathode, typically by a factor of one million.Dyslexia → A learning disorder that manifests itself as a difficulty of understanding or using one or more areas of language, including listening, speaking, reading, writing, and spelling. It is not linked to intelligence or lack of intelligence. This neurological disorder is disorder characterized by omission, distortion, and modification of words while reading.

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