L'histoire assassinee: Manfredo Tafuri and the present

Italian historian Manfredo Tafuri develops his ‘historical project’ in architecture during the 1960’s and 1970’s in three seminal books, which reach the English speaking specialist audience with a certain delay. Histories and Theories of Architecture (1968), which prepares the ground for the redefinition of a critical and independent history of architecture is first translated in English in 1979. Architecture and Utopia (Progetto e utopia, 1973) is translated in 1976, and becomes a point of reference for architectural histories and for the definition of architectural theories, mainly in the United States. The Sphere and the Labyrinth (1980), translated in 1987, is the text which formally defines and presents the ‘historical project’. Tafuri’s dense and highly politicized prose is often subjected in the English versions to numerous simplifications and reductive interpretations. Yet, the time lag and the space between languages that these translations occupy are inhabited by polemical and fertile reactions to the texts from the world of architectural design. Symptomatic of all, Aldo Rossi’s L’architecture assassinée, a rebuke in drawing to some of Tafuri’s remarks in Architecture and Utopia that seemed to suggest -but the interpretation is arguable– the ‘death’ of architecture as project (progetto). Tafuri’s texts instigate a dialogue between architectural history and practice, particularly relevant at a time in the development of the discipline when history was being redefined in its critical role as a ‘project’ –thus appropriating the active and propositional role traditionally assigned to architectural design–, while architectural design –still coping with the legacy of Modernism and with changed production systems- often found itself relegated to the paper of exhibitions, competitions and theoretical projects. This paper explores the relationship between architectural history and design in Tafuri’s work, focusing on recent reconsideration and interpretations of his work. It argues that, beyond instrumental simplifications, Tafuri’s ‘project’ remains active and essential in architecture’s critical culture today.

Magnetic damping of levitated liquid droplets in AC and DC field

The intense AC magnetic field required to produce levitation in terrestrial conditions, along with the buoyancy and thermo-capillary forces, results in turbulent convective flow within the droplet. The use of a homogenous DC magnetic field allows the convective flow to be damped. However the turbulence properties are affected at the same time, leading to a possibility that the effective turbulent damping is considerably reduced. The MHD modified K-Omega turbulence model allows the investigation of the effect of magnetic field on the turbulence. The model incorporates free surface deformation, the temperature dependent surface tension, turbulent momentum transport, electromagnetic and gravity forces. The model is adapted to incorporate a periodic laser heating at the top of the droplet, which have been used to measure the thermal conductivity of the material by calculating the phase lag between the frequency of the laser heating and the temperature response at the bottom. The numerical simulations show that with the gradual increase of the DC field the fluid flow within the droplet is initially increasing in intensity. Only after a certain threshold magnitude of the field the flow intensity starts to decrease. In order to achieve the flow conditions close to the ‘laminar’ a D.C. magnetic field >4 Tesla is required to measure the thermal conductivity accurately. The reduction in the AC field driven flow in the main body of the drop leads to a noticeable thermo-capillary convection at the edge of the droplet. The uniform vertical DC magnetic field does not stop a translational oscillation of the droplet along the field, which is caused by the variation in total levitation force due to the time-dependent surface deformation.

Exploring the conditional performance of UK unit trusts

We evaluate the conditional performance of U.K. equity unit trusts using the approach of Lynch and Wachter (2007, 2008) relative to three conditional linear factor models. We find significant time variation in the conditional performance of some trust portfolios and individual trusts using the lag term spread as the information variable. The conditional performance of the trusts is countercyclical and larger trusts have more countercyclical performance than smaller trusts within certain investment sectors. These patterns in conditional trust performance cannot be fully explained by the underlying securities that the trusts hold.