Locks for luggage

In computer science, conservative two-phase locking (C2PL) is a locking method used in DBMS and relational databases.

Conservative 2PL prevents deadlocks.

The difference between 2PL and C2PL is that C2PL’s transactions obtain all the locks they need before the transactions begin. This is to ensure that a transaction that already holds some locks will not block waiting for other locks.

In heavy lock contention, C2PL reduces the time locks are held on average, relative to 2PL and Strict 2PL, because transactions that hold locks are never blocked.

In light lock contention, C2PL holds more locks than is necessary, because it is hard to tell what locks will be needed in the future, thus leads to higher overhead.

Also, a transaction will not even obtain any locks if it cannot obtain all the locks it needs in its initial request. Furthermore, each transaction needs to declare its read and write set (data items to be read/written during transaction), which is not always possible. Because of these limitations, C2PL is not used very frequently.

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The Kentucky River Authority is an agency of the Commonwealth of Kentucky. Its major purpose is to operate and maintain a set of locks and dams (specifically Locks 5 through 14) along the course of the Kentucky River which was originally built by the U.S. Army Corps of Engineers and are now in the process of being deeded over to the Authority. The KRA was established in 1986.

This system makes the Kentucky River navigable throughout its entire 259 mile (437 km) length from its mouth into the Ohio River all the way up to its headwaters at the confluence of the North and South Forks. However, it is not available for efficient use by many of the modern barge tows due to the relatively small size of the locks and the fact that the channel is maintained to only a six-foot draft rather than the nine-foot draft that is more typical and the standard used on most major river systems in the U.S. The Authority also works to prevent water pollution as much as is practicable along the Kentucky River Basin, in large measure because the stream is the source of the drinking water for approximately one-sixth of all Kentucky residents. The Authority’s responsibility for water quality was added to its mission in 1988 after a serious and prolonged drought brought issues of water quality and availabilty to the fore. In fact, the system is now operated more for the purpose of maintaining a secure supply of drinkable water for Lexington and other communities than it is to maximize navigation.

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Whitchurch Lock is a lock and weir situated on the River Thames in England. The lock is located in the Oxfordshire village of Whitchurch-on-Thames but the weir crosses the river to the Berkshire village of Pangbourne. Both lock and weir are owned and managed by the Environment Agency.

The long serving lock keeper is Brian Butcher who has worked on the river for more than forty years starting as an apprentice engineer for Bert Bushnell’s hire fleet based in Maidenhead in the 1960s.

Access to the lock

Whitchurch Lock is one of the few locks on the River Thames which has no public access other than by boat.

Reach above the lock

The reach passes along the Chiltern Hills, culminating in Goring Gap. On the Oxfordshire side are Hartslock beech woods, named after a lock that was removed in 1910. On the Berksire side is Child Beale Wildlife Park. The Thames Path crosses Whitchurch Bridge into Oxfordshire and continues through Whitchurch away from the river as it goes round Coombe Park, returning to the river at Hartslock. It continues on the Oxfordshire river bank to Goring.

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A party bus (also known as a Party Ride, limo bus, limousine bus or luxury bus) is a large motor vehicle designed to carry 20 or more passengers. Party buses are often driven by chauffeurs.

Party buses offer seating capacities from 20 to 50 passengers and include more amenities and standard equipment than most other forms of ground transportation. These amenities may include upgraded electrical systems, fast idle controller, AM/FM stereo with CD player, power/heated remote control mirrors, power door locks and windows, upgraded seats and fabric, strip-poles, air actuated passenger entry door, video and audio systems, luggage partitions, back-up cameras, seat and fabric upgrades, smoke machines, laser lights, disco lights, strobe lights, on-board restroom, ADA equipment and a large array of floor plans to suit demanding transportation needs.

Party buses are primarily used for, although not limited to, weddings, proms and bachelor and bachelorette parties as well as round trips to casinos, nights on the town, personalized drop offs and pick ups at various bars and nightclubs, birthdays and city tours.

While some party buses are used for week long tours and events, most are used for day trips and events. Most party buses, however, operate as livery vehicles, providing upmarket competition to limousines and taxicabs.

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A duffel bag (or duffle bag), is a large cylindrical bag made of cloth with the closure at the top, often also referred to as a kit bag

The name comes from Duffel, a town in Belgium where the thick cloth the bag is made of originated. Nowadays a Duffel Bag typically refers to the specific style of bag, though the phrase may also be used to refer to any large generic holdall or a bag made of thick fabric.

It is often used to carry luggage or sports equipment by people who travel in the outdoors. Duffel bags are often used by sailors, and are sometimes called seabags in this capacity.

See also:

• Duffel Coat

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Fourteen Locks is a series of locks on the Crumlin arm of the Monmouthshire Canal at Rogerstone in Newport, South Wales. Widely regarded as Britain’s most remarkable staircase lock system , the canal level was raised 160 ft (50 m) in just 800 yd (740 m). Only the top lock is currently in water. The rest of the flight is part of a restoration programme.

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The River Thames falls 234 feet from Lechlade to Sea Level. Over the centuries the flow of water and the danger of flooding has been controlled by a series of Weirs on the River Thames. Weirs, however, presented an obstacle to navigation and to solve this problem Locks on the Thames were built alongside the weirs enabling boats to be moved easily up to the next higher level.

Locks were often built adjacent to islands and so are often situated in remote locations. Those close to main roads and towns tended to become magnets for spectators, while others are very difficut to find. When the motive power was provided by horses, a towpath was needed on the bank side. This towpath has formed the basis for the Thames Path.

There are 45 locks on the Thames. In upstream to downstream order, from source to sea, they are:

• St John’s Lock — the highest lock on the river
• Buscot Lock
• Grafton Lock
• Radcot Lock
• Rushey Lock
• Shifford Lock
• Northmoor Lock
• Pinkhill Lock
• Eynsham Lock
• King’s Lock
• Godstow Lock
• Osney Lock
• Iffley Lock
• Sandford Lock
• Abingdon Lock
  
• Culham Lock
• Clifton Lock
• Day’s Lock
• Benson Lock
• Cleeve Lock
• Goring Lock
• Whitchurch Lock
• Mapledurham Lock
• Caversham Lock
• Sonning Lock
• Shiplake Lock
• Marsh Lock
• Hambleden Lock
• Hurley Lock
• Temple Lock
• Marlow Lock
• Cookham Lock
• Boulter’s Lock
• Bray Lock
• Boveney Lock
• Romney Lock
• Old Windsor Lock
• Bell Weir Lock
• Penton Hook Lock
• Chertsey Lock
• Shepperton Lock
• Sunbury Lock
• Molesey Lock
• Teddington Lock — the last lock before the river becomes tidal
• Richmond Lock — on the tidal Thames. Owned and operated by the Port of London Authority

Additionally, Blake’s Lock is located on a reach of the River Kennet that is administered as part of the River Thames, and is often counted as a Thames Lock.

All the locks on the Thames (including Blake’s Lock) are manned and, except for Richmond Lock, are owned and operated by the Environment Agency. The Environment Agency still has the two responsibilities of managing the flow of water to control flooding, and providing for navigation.

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Fobney Lock is a lock on the River Kennet in the Small Mead area of Reading in the English county of Berkshire.

Fobney Lock was built between 1718 and 1723 under the supervision of the engineer John Hore of Newbury, and this stretch of the river is now administered by British Waterways and known as the Kennet Navigation. It has a rise/fall of 7 ft 8 in (2.24 m).

There have been ongoing plans to turn Fobney Island, adjacent to the lock, into a wetlands nature reserve.

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The McAlpine Locks and Dam refers to the series of locks and the hydroelectric dam in Louisville, Kentucky at the Falls of the Ohio. They are located at mile point 606.8 and control a 72.9 mile (117 km) long navigation pool. This was the first major engineering project on the Ohio River, and the first official name of the system of canal locks was the Louisville and Portland Canal, which was completed in 1830 to allow shipping traffic to navigate through the Falls of the Ohio. From 1925 to 1927, a dam for generating hydroelectric power was added, and the system of canals was expanded, first by a private company and then by the U.S. Army Corps of Engineers. The hydroelectric plant at the time was the seventh largest hydroelectric plant in the United States.

The system was renamed the McAlpine Locks and Dam in 1960 in honor of William McAlpine, who was the only civilian to have ever served as district engineer for the Corps of Louisville. At present, the normal pool elevation is 420 feet (130 m) above sea level and the drainage area above the dam is 91,170 square miles (236,000 km²). The average daily flow at McAlpine is 118,000 cubic feet per second (3,340 m³/s). The lock chambers are located at the dam on the Kentucky side of the Ohio River and are capable of a normal lift of 37 feet (11 m) between the McAlpine pool upstream and the Cannelton pool downstream. The hydroelectric plant consists of eight turbine units with a net power generation capacity of 80,000 kilowatts. The hydroelectric plant is currently undergoing an 8-year long rehabilitation project. This will extend the life of the 1920s era turbine-generator units and increase power output to 100 megawatts.

In October 2003, McAlpine was designated a Historic Civil Engineering Landmark by the American Society of Civil Engineers.

The McAlpine locks are currently undergoing a 10-year, $278 million expansion project scheduled to be completed in 2008.

The hydroelectric plant is owned and operated by LG&E, a subsidiary of E.ON U.S., while the locks are operated by the Army Corps of Engineers.

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The Great Lakes Waterway is a system of channels and canals that makes all of the Great Lakes accessible to oceangoing vessels. Its principal civil engineering components are the Welland Canal, bypassing Niagara Falls between Lake Ontario and Lake Erie, and the Soo Locks, bypassing the rapids of the St. Marys River between Lake Superior and Lake Huron, at Sault Sainte Marie. Maintained channels serve the St. Clair River and Detroit River between Lake Huron and Lake Erie. A United States Coast Guard icebreaker helps keep the passage open for much of the winter, although shipping usually ceases for 2 or 3 months each year.

The Great Lakes Waterway is supplemented by the Saint Lawrence Seaway, which makes the Saint Lawrence River navigable from Montreal to Kingston, Ontario. The two waterways are often jointly referred to as the St. Lawrence Seaway. The Great Lakes Seaway has larger locks and deeper drafts than the St. Lawrence Seaway with the result that a number of lake freighters are confined to the lakes, being small enough to operate on the Waterway but too large to pass down the Seaway.

The Great Lakes Waterway is co-administered by Canada and the United States.

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