A system intended to supply emergency cooling to limit fuel damage and maintain heat removal following a coolant-loss event. Its performance depends on the accident conditions and flow paths as well as nominal injection capability.

In a station frame, a target begins at $(0,a)$ with velocity $(v,0)$, and an interceptor launches from the origin at speed u greater than v. Straight-line interception requires its velocity components to be $(v,\sqrt{u^2-v^2})$, and takes station time $t=a/\sqrt{u^2-v^2}$. The target-frame coordinate interval is ${\gamma }_v(t-v\Delta x/c^2)=t/{\gamma }_v$, since $\Delta x=vt$. This differs from the interceptor's proper time $t/{\gamma }_u$. A symmetric return to the stationary launch point instead has target-frame round-trip coordinate duration $2{\gamma }_{v}t$, because its endpoint spatial separation in the station frame is zero.

Coupling across an allylic four-bond path, such as between an oxygen-bound CH2 group and terminal vinyl hydrogens in an allyl ester.

A generalized gradient approximation models the exchange and correlation contribution in density functional theory using both the local electron density $n(\mathbf{r})$ and its spatial gradient $\nabla n(\mathbf{r})$. Its schematic form is $E_{\mathrm{xc}}[n]=\int f(n,\nabla n)d^{3}r$. It extends the local density approximation, which uses only the density at each point.

Two regions with equal density can therefore receive different energy contributions if one is nearly uniform and the other varies rapidly. This makes the approximation useful for chemical bonds, surfaces and molecular tails. The improvement is still approximate: adding density gradients does not automatically recover every long-distance interaction or the exact exchange potential. The Becke 1988 exchange functional is an example of a gradient-dependent exchange model.

The Li2 molecule. Its two valence electrons occupy a primarily 2s-derived bonding orbital; filled 1s-derived bonding and antibonding core levels do not give an additional net simple bond-order contribution.

The Li3 molecule, with three valence electrons and a bound distorted triangular structure. The equilateral open-shell arrangement is subject to Jahn-Teller coupling; electron counting alone does not establish dissociation energetics.

Greg Wilson is the first-listed author of Best Practices for Scientific Computing by Greg Wilson and others, which connects reliable scientific results to maintainable software. Its recommendations include software testing, version control, small reusable components and review of changes. These practices make it possible to inspect how an analysis was produced and detect mistakes when its implementation changes.^[ref]

A paleontologist who investigated early mammalian anatomy and relationships, including competing interpretations of the origin of tribosphenic teeth.^[ref]

A paleontologist who investigated terrestrial early cetacean endoskeletons and their relationship to artiodactyls.^[ref]

A paleontologist who studied early cetacean limbs, using pelvis, foot and ankle anatomy to investigate the transition from terrestrial ancestors.^[ref]

A paleontologist who combined morphological and molecular evidence to investigate the transition from teeth to baleen in cetaceans.^[ref]

A paleontologist who investigated three-dimensional tooth complexity and its relationship to diet in different mammalian lineages.^[ref]

A paleontologist who studied horse dietary change, comparing dental wear with the evolution of tooth crown height.^[ref]

A paleontologist who investigated relationships between digestive strategy and the evolution of herbivorous mammals, including horses.^[ref]

A paleontologist who described a Jurassic mammal from Madagascar, using its jaw and teeth to investigate early mammalian relationships.^[ref]

A paleontologist who investigated the origin of tribosphenic teeth, using phylogenetics analysis to test competing histories of mammalian dental evolution.^[ref]