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Topic Review
Nanotechnology Education
Nanotechnology education involves a multidisciplinary natural science education with courses such as physics, chemistry, mathematics and molecular biology. It is being offered by many universities around the world. The first program involving nanotechnology was offered by the University of Toronto's Engineering Science program, where nanotechnology could be taken as an option. Here is a partial list of universities offering nanotechnology education, and the degrees offered (Bachelor of Science, Master of Science, and/or Ph.D in Nanotechnology).
  • 623
  • 14 Oct 2022
Topic Review
Recombination Mediators Proteins
The recombination mediator proteins (RMPs) are ubiquitous and play a crucial role in genome stability. RMPs facilitate the loading of recombinases like RecA onto single-stranded (ss) DNA coated by single-strand binding proteins like SSB.
  • 622
  • 22 Apr 2021
Topic Review
Holeum
Holeums are hypothetical stable, quantized gravitational bound states of primordial or micro black holes. Holeums were proposed by L. K. Chavda and Abhijit Chavda in 2002. They have all the properties associated with cold dark matter. Holeums are not black holes, even though they are made up of black holes.
  • 620
  • 28 Sep 2022
Topic Review
Photoacoustic Imaging Techniques
2D materials can be used as carriers for delivering therapeutic agents into a lesion, leading to phototherapy. Various optical imaging techniques have been used for the monitoring of the treatment process. 
  • 616
  • 21 Feb 2021
Topic Review
Shock Capturing Method
In computational fluid dynamics, shock-capturing methods are a class of techniques for computing inviscid flows with shock waves. The computation of flow containing shock waves is an extremely difficult task because such flows result in sharp, discontinuous changes in flow variables such as pressure, temperature, density, and velocity across the shock.
  • 615
  • 25 Nov 2022
Topic Review
Yajnavalkya's 95 Years Cycle of Synchronisation
Yajnavalkya's 95 Years Cycle of Synchronisation is the model proposed by the great Indian philosopher Yajnavalkya which explains the mathematical concept of the synchronisation of the motions of the Sun and the Moon. Yajnavalkya invented the 95 years of the periodic cycle, when the solar and lunar motions get synchronised. This 95 years of the periodic cycle is also known as Yajnavalkya Cycle. 
  • 615
  • 25 Dec 2023
Topic Review
SWCNTs in Magnetic Recording
Applications in magnet-recording devices rely on the combination and emergence of unique properties of single-walled carbon nanotubes (SWCNTs) and encapsulated materials. The entry “SWCNTs in magnetic recording” focuses on applications of filled SWCNTs in magnetic recording.
  • 612
  • 11 Nov 2021
Topic Review
Onium Compound
In chemistry, an onium ion is a cation formally obtained by the protonation of mononuclear parent hydride of a pnictogen (group 15 of the periodic table), chalcogen (group 16), or halogen (group 17). The oldest-known onium ion, and the namesake for the class, is ammonium, NH+4, the protonated derivative of ammonia, NH3. The name onium is also used for cations that would result from the substitution of hydrogen atoms in those ions by other groups, such as organic radicals, or halogens; such as tetraphenylphosphonium, (C6H5)4P+. The substituent groups may be divalent or trivalent, yielding ions such as iminium and nitrilium. A simple onium ion has a charge of +1. A larger ion that has two onium ion subgroups is called a double onium ion, and has a charge of +2. A triple onium ion has a charge of +3, and so on. Compounds of an onium cation and some other negative ion are known as onium compounds or onium salts. Onium ions and onium compounds are inversely analogous to -ate ions and ate complexes:
  • 612
  • 16 Nov 2022
Topic Review
The Andromeda Galaxy
Star formation histories of galaxies are critically important for understanding the process of galaxy formation and the structure and contents of galaxies. Star formation can and has been studied in local galaxies for which the stellar populations are resolved and in more distant galaxies for which stars are unresolved, which are instead modeled as populations. Structural components of a galaxy can be resolved at much larger distances. The structural components include those long recognized, such as bulge, disk and halo. More recently recognized structures include separation of disks into thin and thick disk components and stellar streams, as well as recognition of significant numbers of dwarf companion galaxies. Stellar streams are the most recently recognized components of galaxies, mainly using observations of the Milky Way and the Andromeda Galaxy (M31).
  • 610
  • 14 Aug 2023
Topic Review
Epoch
In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving the positions and velocities of astronomical objects in the sky at a given time or times. Astronomical quantities can be specified in any of several ways, for example, as a polynomial function of the time-interval, with an epoch as a temporal point of origin (this is a common current way of using an epoch). Alternatively, the time-varying astronomical quantity can be expressed as a constant, equal to the measure that it had at the epoch, leaving its variation over time to be specified in some other way—for example, by a table, as was common during the 17th and 18th centuries. The word epoch was often used in a different way in older astronomical literature, e.g. during the 18th century, in connection with astronomical tables. At that time, it was customary to denote as "epochs", not the standard date and time of origin for time-varying astronomical quantities, but rather the values at that date and time of those time-varying quantities themselves. In accordance with that alternative historical usage, an expression such as 'correcting the epochs' would refer to the adjustment, usually by a small amount, of the values of the tabulated astronomical quantities applicable to a fixed standard date and time of reference (and not, as might be expected from current usage, to a change from one date and time of reference to a different date and time).
  • 610
  • 22 Nov 2022
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