Buried pipeline systems are commonly used to transport water, sewage, oil, natural gas and other materials. In the conterminous United States, there are about 77,109 km (47,924 miles) of crude oil pipelines, 85,461 km (53,114 miles) of refined oil pipelines and 67,898 km (42,199 miles) of natural gas pipelines (FEMA, 1991). The total length of water and sewage pipelines is not readily available...

Hartmann’s procedure, first described by the French surgeon Henri Albert Hartmann in 1921, is one of the most commonly performed operations. This paper examines the history behind this operation and assesses its significance in modern surgical practice.

P. Ceppi, Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, Washington 98195-1640, USA. ([email protected]) Y.-T. Hwang, Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, Washington 98195-1640, USA. ([email protected]) X. Liu, Department of Atmospheric Sciences, University of Washington, Box 351640, Seattle, Was...

Since the beginning of the twenty-first century, there has been widespread construction of submarine oil-gas transmission pipelines due to an increase in offshore oil exploration. Vessel anchoring operations are causing more damage to submarine pipelines due to shipping transportation also increasing. Therefore, it is essential that the influence of anchoring on the required burial depth of sub...

We revisit the method of Chvátal, Cook, and Hartmann to establish lower bounds on the Chvátal-Gomory rank and develop a simpler method. We provide new families of polytopes in the 0/1 cube with high rank and we describe a deterministic family achieving a rank of at least (1+ 1/e)n− 1> n. Finally, we show how integrality gaps lead to lower bounds.