 |
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (January 2009) |
A block chain, also called a "bar-link" or "block-and-bar" chain, is a mechanical drive chain. It is composed of side plates, where each plate straddles one end of a block and is connected to the block with a pin going through a hole at one end of the block. Block chain is simple, but compared to modern roller chain is heavy and is less efficient rolling over sprockets due to the lack of rolling motion as the chain engages and disengages the sprockets. However, it has advantages in specific applications and while not dimensionally standard like roller chain, it is commonly used for specific applications, especially where no sprockets are needed, loads are very high and strength is greater concern than efficiency, and where the chain has special fixtures for holding or engaging a load[1]
References [link]
- ^ Chains for Power Transmission and Material Handling. Marcel Dekker, Inc.. 1982.
https://wn.com/Block_chain
Block chain (database)
A block chain or blockchain is a permissionless distributed database based on the bitcoin protocol that maintains a continuously growing list of data records hardened against tampering and revision, even by its operators. The initial and most widely known application of block chain technology is the public ledger of transactions for bitcoin, which has been the inspiration for similar implementations often known as altchains.
Etymology
The block chain consists of blocks that hold timestamped batches of recent valid transactions. Each block includes the hash of the prior block, linking the blocks together. The linked blocks form a chain, with each additional block reinforcing those before it, thus giving the database type its name.
Model
A block chain implementation consists of two kinds of records: transactions and blocks.
Transactions
Transactions are the content to be stored in the block chain.Transactions are created by participants using the system. In the case of cryptocurrencies, a transaction is created anytime a bitcoin owner sends cryptocurrency to another.
