Disallowances and overcapitalization in the U.S. electric utility industry

Regulation of an industry often produces unintended consequences. Averch and Johnson (1962) argue that certain regulation of electric utilities provides utilities the incentive to purchase an inefficiently large amount of capital. Another possible and related unintended consequence of electric utility regulation is that regulatory cost disallowances on capital may also increase utilities' incentives to overcapitalize. The authors provide theoretical evidence that capital expenditure disallowances will increase the Averch and Johnson effect in some instances and thus may have contributed to the overcapitalization problem that regulation was designed to discourage. Our model shows that disallowances can reduce the rate of return on investment and thereby increase the Averch and Johnson distortion.Electric utilities ; Energy industries

Taking Place 8: Interstitial Breakfast

A contextualised presentation of an interstitial act by taking place at the AHRA conference Architecture and Feminisms: Ecologies, Economies, Technologies: 13th International Architectural Humanities Research Association Conference, KTH School of Architecture Stockholm 17-19 November 2016. Taking place (Jos Boys, Julia Dwyer, Teresa Hoskyns, Katie Lloyd Thomas and Helen Stratford) curated their 8th spatial intervention, tp8, a breakfast held early on the second conference day which addressed through conversation and evidence marked into table cloths , the conference participants' responses to an open call by taking place to the question “What are the relevant questions for architecture and feminism today

Dynamic testing and analysis of the world’s first metal 3D printed bridge

The MX3D Bridge is the world’s first additively manufactured metal bridge. It is a 10.5 m-span footbridge, and its dynamic response is a key serviceability consideration. The bridge has a flowing, sculptural form and its response to footfall was initially studied using a 3D finite element (FE) model featuring the designed geometry and material properties obtained from coupon tests. The bridge was tested using experimental modal analysis (EMA) and operational modal analysis (OMA) during commissioning prior to installation. The results have shown that the measured vibration response of the bridge under footfall excitation is 200% greater than predictions based on the FE model and contemporary design guidance. The difference between predicted and measured behaviour is attributed to the complexity of the structure, underestimation of the modal mass in the FE model, and the time-variant modal behaviour of the structure under pedestrian footfall. Both OMA and EMA give a dominant natural frequency for the bridge of between 5.19 Hz and 5.32 Hz, higher than the FE model prediction of 4.31 Hz, and average damping estimates across all modes of vibration below 15 Hz of 0.61% and 0.74% respectively, higher than the 0.5% assumed within the design guidance, slightly reducing the peak response factor predicted for the bridge