VTA adjustment is made via a helicoid
thread knob with lock.
For centuries, the plane and the helicoid
were the only known examples of infinite, unbounded minimal surfaces that don't fold back to intersect themselves.
A roof prism design, it sports central focusing, click stops on the eyepiece diopter, and helicoid
Further notes on Helicoid
Land Shells from Japan, The Loo-Choo, and Bonin Islands, with descriptions of seven new species.
A type of inflorescence in which there is a single terminal flower, and below this a single branch bearing one or more younger flowers; variations of coiled and zigzag patterns include helicoid
, cincinnus, bostryx, and scorpioid.
A coiled inflorescence has several variations called helicoid
, cincinnus, and bostryx.
A particular form of inflorescence typifies some plant families, such as the compound umbel of Apiaceae (Umbelliferae), the ultimate spike of Gramineae, the capitulum or head of Asteraceae, the helicoid
cyme of Boraginaceae, and the spadix of Araceae.
Typically, the compound flows into a helicoid
, a cylinder that deflects and distributes the flow of compound around a core tube, which slides into the helicoid
and holds the mandrel.
Rather, there is growing support for viewing limpets as a divergent group (Ponder and Lindberg, 1996) whose ancestors may have had internal fertilization with introsperm, a helicoid
larval shell (Page, 1994), and primitive ctenidia.
From the illustrations one can see, with some effort, that the helicoid
is deformable to a plane, whereas the catenoid is deformable to a cylinder.
Descriptions of new helicoid
shells from Cape Colony.