In chemistry, sigma bonds (s bonds) are the strongest type of covalent chemical bond. They are formed by head-on overlapping between atomic orbitals. Sigma bonding is most simply defined for diatomic molecules using the language and tools of symmetry groups. In this formal approach, a s-bond is symmetrical with respect to rotation about the bond […]

A force-sensing resistor is a material whose resistance changes when a force, pressure or mechanical stress is applied. They are also known as force-sensitive resistor and are sometimes referred to by the initialism FSR. The technology of force-sensing resistors was invented and patented in 1977 by Franklin Eventoff. In 1985 Eventoff founded Interlink Electronics, a […]

Candida albicans is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40-60% of healthy adults. It is usually a commensal organism, but it can become pathogenic in immunocompromised individuals under a […]

Upcycling, also known as creative reuse, is the process of transforming by-products, waste materials, useless, or unwanted products into new materials or products perceived to be of greater quality, such as artistic value or environmental value. Upcycling is the opposite of downcycling, which is the other part of the recycling process. Downcycling involves converting materials […]

M13 is one of the Ff phages (fd and f1 are others), a member of the family filamentous bacteriophage (inovirus). Ff phages are composed of circular single-stranded DNA (ssDNA), which in the case of the m13 phage is 6407 nucleotides long and is encapsulated in approximately 2700 copies of the major coat protein p8, and […]

Lev Andreevich Navrozov (Russian: LEV ANDREEVIC NAVROZOV; 26 November 1928 - 22 January 2017) was a Russian author, historian and polemicist, born in Moscow and father of poet Andrei Navrozov. A leading translator of Russian texts into English under the Soviet regime, Navrozov emigrated to the United States in 1972, where he published a best-selling […]

Hydromelonic acid, is an elusive chemical compound with formula C9H3N13 or (HNCN)3(C6N7), whose molecule would consist of a heptazine H3(C6N7) molecule, with three cyanamido groups H-N=C=N- or N≡C-NH- substituted for the hydrogen atoms. The compound had not been properly isolated as of 2010, due to its tendency to polymerize. However, removal of three protons yields […]

A Van Hove singularity is a singularity (non-smooth point) in the density of states (DOS) of a crystalline solid. The wavevectors at which Van Hove singularities occur are often referred to as critical points of the Brillouin zone. For three-dimensional crystals, they take the form of kinks (where the density of states is not differentiable). […]