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Sails are classified as "triangular sails", "quadrilateral fore-and-aft sails" (gaff-rigged, etc.), and "square sails". [38] The top of a triangular sail, the head , is raised by a halyard , The forward lower corner of the sail, the tack , is shackled to a fixed point on the boat in a manner to allow pivoting about that point—either on a mast ...
Building blocks are used for bottom-up modular assembly of molecular architectures: nano-particles, [2] [3] metal-organic frameworks, [4] organic molecular constructs, supra-molecular complexes. [5] Using building blocks ensures strict control of what a final compound or a (supra)molecular construct will be. [6]
Examples also included microparticles with complex geometries, such as hemispherical, [19] dimer, [20] discs, [21] rods, molecules, as well as multimers. These nanoscale building blocks can in turn be synthesized through conventional chemical routes or by other self-assembly strategies such as directional entropic forces. More recently, inverse ...
The six aforementioned elements are used by organisms in a variety of ways. Hydrogen and oxygen are found in water and organic molecules, both of which are essential to life. Carbon is found in all organic molecules, whereas nitrogen is an important component of nucleic acids and proteins.
Square rig is a generic type of sail and rigging arrangement in which the primary driving sails are carried on horizontal spars which are perpendicular, or square, to the keel of the vessel and to the masts. These spars are called yards and their tips, outside the lifts, are called the yardarms. [1] A ship mainly rigged so is called a square ...
Offshore cruising mainsails sometimes have a hollow leech (the inverse of a roach) to obviate the need for battens and their ensuing likelihood of chafing the sail. [40] The roach on a square sail design is the arc of a circle above a straight line from clew to clew at the foot of a square sail, which allows the foot of the sail to clear stays ...
Alan Jackson, the water manager of the Bingham Groundwater District, said these incentives show up clearly in the numbers. The average groundwater user puts between 1.6 and 2.0 feet of water on ...
C. Griffin showed an amorphous supramolecular material using a single hydrogen bond between a homotropic molecules having carboxylic acid and pyridine termini. [15] The idea to make mechanically strong polymeric materials by 1D supramolecular association of small molecules requires a high association constant between the repeating building blocks.