The Freedom Tower

When the Twin Towers of the World Trade Centre came crashing down on 9/11, New York not only mourned the loss of life hut also lost a part of its iconic architectural heritage. On 28 June 2006, New York Governor, George E. Pataki, announced a new building that will be built on the site. The Freedom Tower development will in fact be a number of skyscrapers, including The Freedom Tower itself. World Trade Centre Office Towers 2, 3 and 4, as well as the World Trade Centre Memorial and Memorial Museum and will cover an 8-acre site in central Manhattan. 

The Freedom Tower and World Trade Centre Office Towers 2, 3 and 4 will be partially fuelled by four 1.2 MW fuel cell systems (4.8 MW in total) to be acquired by the New York Power Authority (NYPA). Also, The Freedom Tower, World Trade Centre Transportation Hub, Memorial and Memorial Museum will be powered by 184 million kW of renewable energy. NYPA will purchase 93 million KW hours of renewable energy credits (RECs) and Silverstein Properties, the developers, will also purchase a further 91 million KW hours of RECs for Towers 2, 3 and 4. 

FIGURE 19-12 Buildings such as the new Freedom Tower reach incredible heights and require sound scientific and mathematical models. 

The freedom with which the continuous phase can recirculate in the spray tower may lead to a lowering of extraction efficiency because of the lack of true countercurrent flow. 

The confined volume for a multi-level unit in a chemical plant is very frequently the volume within the structural steel framework supporting the equipment, with possible exceptions where there are ground level items, such as towers, adjoining a multi-level unit. Frequently, the uppermost level of a multi-level unit has very little equipment, and it is overly conservative to extend the confined volume all the way up to the top of the equipment on the upper deck. A reasonable judgment must be made during a site inspection based on the freedom with which a flame can expand away from a confined zone. 

Drug discovery has become much more integrated with the other main functions of a pharmaceutical company, i.e. drug development and marketing. Discovery is no longer done in an ivory tower with unlimited freedom for the scientist to select topics for research. Nowadays, in most big pharmaceutical companies, the areas of research are chosen in close collaboration with marketing and development, usually as part of a comprehensive therapeutic... 

The accompanying figure represents the schematic flowsheet of a distillation tower used to recover gasoline from the products of catalytic cracker. Is the problem completely specified, that is, is the number of degrees of freedom equal to zero for the purpose of calculating the heat transfer to the cooling water in the condenser ... 

The dynamic response analysis of an offshore tower, subjected to nonstationary ice forces, is presented for single-degree-of freedom and multi-degree-of-freedom, lumped mass, models based on evolutionary covariance matrices. The ice force excitation is idealized by i) equivalent evolutionary white noise, and ii) physical spectra. The mean square responses are computed in the time domain using the linear (state space formulation). The relationship between the physical spectrum and instantaneous spectrum analysis is discussed, and the need indicated for a study of the influence of ice force physical spectrum parameters on the response. 

The tower was modeled using 8-node brick elements. A relatively large number of finite elements have been used in the model, so that a regular distribution of masses could be obtained, and all the geometric variations and openings in the load-bearing walls could be reasonably represented. The model consists of 3,475 solid elements with 17,052 active degrees of freedom. 

GL 2010 gives no particular prescriptions on the structural model to be adopted. However, because at least three modes have to be included in the vibration response, the use of a multi-degree-of-freedom (MDOF) structural model is implicitly suggested. In general, a linear elastic behavior shall be assumed. A ductile response can be considered only when the support structure has a sufficient static redundancy, such as a lattice tower. However, if ductile behavior is assumed, the structure shall be mandatorily inspected after occurrence of an earthquake. 

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