Rope

A rope is a group of yarns, plies, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting, but are too flexible to provide compressive strength. As a result, they cannot be used for pushing or similar compressive applications. Rope is thicker and stronger than similarly constructed cord, line, string, and twine. Ropes made from metal strands are called wire rope.

Construction

Rope may be constructed of any long, stringy, fibrous material, but generally is constructed of certain natural or synthetic fibres. Synthetic fibre ropes are significantly stronger than their natural fibre counterparts, but also possess certain disadvantages, including slipperiness.

Common natural fibres for rope are manila hemp, hemp, linen, cotton, coir, jute, straw, and sisal. Synthetic fibres in use for rope-making include polypropylene, nylon, polyesters (e.g. PET, LCP, HDPE, Vectran), polyethylene (e.g. Dyneema and Spectra), Aramids (e.g. Twaron, Technora and Kevlar) and acrylics (e.g. Dralon). Some ropes are constructed of mixtures of several fibres or use co-polymer fibres. Wire rope is made of steel or other metal alloys. Ropes have been constructed of other fibrous materials such as silk, wool, and hair, but such ropes are not generally available. Rayon is a regenerated fibre used to make decorative rope.

Rope (data structure)

In computer programming, a rope, or cord, is a data structure composed of smaller strings that is used for efficiently storing and manipulating a very long string. For example, a text editing program may use a rope to represent the text being edited, so that operations such as insertion, deletion, and random access can be done efficiently.

Description

A rope is a binary tree having leaf nodes that contain a short string. Each node has a weight value equal to the length of its string plus the sum of all leaf nodes' weight in its left subtree, namely the weight of a node is the total string length in its left subtree for a non-leaf node, or the string length of itself for a leaf node. Thus a node with two children divides the whole string into two parts: the left subtree stores the first part of the string. The right subtree stores the second part and its weight is the sum of the left child's weight and the length of its contained string.

The binary tree can be seen as several levels of nodes. The bottom level contains all the nodes that contain a string. Higher levels have fewer and fewer nodes. The top level consists of a single "root" node. The rope is built by putting the nodes with short strings in the bottom level, then attaching a random half of the nodes to parent nodes in the next level.

Rope (unit)

A rope may refer to any of several units of measurement initially determined or formed by ropes or knotted cords.

Length

The Greco-Roman schoenus, supposedly based on an Egyptian unit derived from a wound reed measuring rope, may also be given in translation as a "rope". According to Strabo, it varied in length between 30 to 120 stadia (roughly 5 to 20 km) depending on local custom.

The Byzantine equivalent, the schoinion or "little rope", varied between 60 to 72 Greek feet depending upon the location.

The Thai sen of 20 Thai fathoms or 40 m also means and is translated "rope".

The Somerset rope was a former English unit used in drainage and hedging. It was 20 feet (now precisely 6.096 m).

Area

The Romans used the schoenus as an alternate name for the half-jugerum formed by a square with sides of 120 Roman feet.

In Somerset, the rope could also double as a measure of area equivalent to 20 feet by 1 foot. Walls in Somerset were formerly sold "per rope" of 20 sq ft.

Garlic

In medieval English units, the rope of garlic was a set unit of 15 heads of garlic. 15 such ropes made up the "hundred" of garlic.

Parkdale

Parkdale can refer to several different things:

Communities

Electoral Districts

Parkdale (provincial electoral district)

Parkdale was a provincial riding electing Members of Provincial Parliament (MPP) to the Legislative Assembly of Ontario. The riding was created from the western part of Toronto West riding in 1914 and abolished in 1996 and redistributed into the Parkdale—High Park, Davenport and Trinity—Spadina ridings for the 1999 Ontario general election.

Boundaries

1914, 1919 & 1923

Parkdale, Toronto

Parkdale is a neighbourhood and former village in Toronto, Ontario, Canada, west of downtown. The neighbourhood is bounded on the west by Roncesvalles Avenue, on the north by the CP Rail line where it crosses Queen Street and Dundas Street. It is bounded on the east by Dufferin Street from Queen Street south, and on the south by Lake Ontario. The original village incorporated an area north of Queen Street, east of Roncesvalles from Fermanagh east to the main rail lines, today known as part of the Roncesvalles neighbourhood. The village area was roughly one square kilometer in area. The City of Toronto extends the neighbourhood boundaries to the east, south of the CP Rail lines, east to Atlantic Avenue, as far south as the CN Rail lines north of Exhibition Place, the part south of King Street commonly known as the western half of Liberty Village neighbourhood.

Parkdale was founded as an independent settlement within York County in the 1850s. It became an incorporated village in 1879 and later joined Toronto in 1889. It was an upper income residential area for the first half of the 20th Century, with several notable mansions. The area changed dramatically with the building of the Gardiner Expressway in 1955, demolishing the southern section of the neighbourhood together with the Sunnyside Amusement Park, and the creation of a barrier between the neighbourhood and the lake shore. A boom in apartment building construction followed, replacing whole blocks of homes with blocks of apartment buildings. Some of the older large residential buildings remain though many were converted into rooming houses. The demographic composition changed considerably, including a higher proportion of lower incomes and newcomer families. Today, it is a working-class neighbourhood, with a large percentage of low-income households (concentrated in South Parkdale), and an entry point for new immigrants, most recently South Asians and Tibetan.