Long Term Monitoring of CFA Energy Pile Schemes in the UK

Energy pile schemes involve the use of structural foundations as heat exchangers in a ground source heat pump system. Such schemes are attractive, as they reduce energy consumption compared with traditional building heating and cooling systems. As energy prices increase and governments introduce subsidies they are also proving increasingly economically attractive. Additionally, energy piles can contribute to reducing the carbon dioxide emissions associated with a development. However, this approach to heating and cooling building remains relatively novel and the lack of published long term performance data remains a barrier to further implementation. Two issues remain to be addressed by long term monitoring. First, the need for a database of operational energy piles schemes were the energy performance is proven over many years. Secondly, availability of long term datasets of pile thermal behavior that can be used to validate design approaches and tools and hence encourage less conservative design practices. This paper presents the initial results from a study aimed at tackling these issues through long term instrumentation and monitoring of two energy pile schemes in the United Kingdom

The attachments of the anteromedial and posterolateral fibre bundles of the anterior cruciate ligament. Part 2: femoral attachment.

Accepted versio

The attachments of the anteromedial and posterolateral fibre bundles of the anterior cruciate ligament: Part 1: tibial attachment.

Accepted versio

Thermal performance of thermoactive continuous flight auger piles

Foundation piles are being increasingly equipped with heat exchangers to efficiently harvest shallow geothermal energy. For buildings in urban areas, continuous flight auger (CFA) piles are common owing to their speed, cost-efficiency and low noise levels. To construct a thermoactive CFA pile usually requires separate central installation of the heat exchanger. However, the energy performance of this type of pile has not been investigated systematically, with most studies focused on rotary piles where the heat exchanger is attached to the reinforcing cage. In this work, insights are provided about the main influences on the energy efficiency of thermoactive CFA piles, with a focus on the implications of using CFA construction techniques rather than rotary boring. An innovative three-dimensional numerical model, able to capture the different aspects of transient heat transfer, is employed together with analytical methods to evaluate the transient and steady-state behaviour of energy piles in a number of design situations. Attention is given to understanding the role of possible pipe-to-pipe interaction, which cannot be systematically investigated with standard methods. Finally, practical guidelines on the optimal choice of design parameters to maximise the energy efficiency of CFA piles, without altering the geotechnical arrangements, are provided

Segond's fracture: a biomechanical cadaveric study using navigation

Background Segond’s fracture is a well-recognised radiological sign of an anterior cruciate ligament (ACL) tear. While previous studies evaluated the role of the anterolateral ligament (ALL) and complex injuries on rotational stability of the knee, there are no studies on the biomechanical effect of Segond’s fracture in an ACL deficient knee. The aim of this study was to evaluate the effect of a Segond’s fracture on knee rotation stability as evaluated by a navigation system in an ACL deficient knee. Materials and methods Three different conditions were tested on seven knee specimens: intact knee, ACL deficient knee and ACL deficient knee with Segond’s fracture. Static and dynamic measurements of anterior tibial translation (ATT) and axial tibial rotation (ATR) were recorded by the navigation system (2.2 OrthoPilot ACL navigation system B. Braun Aesculap, Tuttlingen, Germany). Results Static measurements at 30 showed that the mean ATT at 30 of knee flexion was 5.1 ± 2.7 mm in the ACL intact condition, 14.3 ± 3.1 mm after ACL cut (P = 0.005), and 15.2 ± 3.6 mm after Segond’s fracture (P = 0.08). The mean ATR at 30 of knee flexion was 20.7 ± 4.8 in the ACL intact condition, 26.9 ± 4.1 in the ACL deficient knee (P[0.05) and 30.9 ± 3.8 after Segond’s fracture (P = 0.005). Dynamic measurements during the pivot-shift showed that the mean ATT was 7.2 ± 2.7 mm in the intact knee, 9.1 ± 3.3 mm in the ACL deficient knee(P = 0.04) and 9.7 ± 4.3 mm in the ACL deficient knee with Segond’s fracture (P = 0.07). The mean ATR was 9.6 ± 1.8 in the intact knee, 12.3 ± 2.3 in the ACL deficient knee (P[0.05) and 19.1 ± 3.1 in the ACL deficient knee with Segond’s lesion (P = 0.016). Conclusion An isolated lesion of the ACL only affects ATT during static and dynamic measurements, while the addition of Segond’s fracture has a significant effect on ATR in both static and dynamic execution of the pivot-shift test, as evaluated with the aid of navigation

Change management: The case of the elite sport performance team

The effective and efficient implementation of change is often required for both successful performance and management survival across a host of contemporary domains. However, although of major theoretical and practical significance, research to date has overlooked the application of change management (hereafter CM) knowledge to the elite sport performance team environment. Considering that the success of ‘off-field’ sports businesses are largely dependent on the performances of their ‘on-field’ team, this article explores the application of current CM theorizing to this specific setting and the challenges facing its utility. Accordingly, we identify the need and importance of developing theory specific to this area, with practical application in both sport and business, through examination of current knowledge and identification of the domain's unique, dynamic and contested properties. Markers of successful change are then suggested to guide initial enquiry before the article concludes with proposed lines of research which may act to provide a valid and comprehensive theoretical account of CM to optimize the research and practice of those working in the field

Sport clubs in France

International audienc

Energy performance of diaphragm walls used as heat exchangers

The possibility of equipping diaphragm walls as ground heat exchangers to meet the full or partial heating and cooling demands of overlying or adjacent buildings has been explored in recent years. In this paper, the factors affecting the energy performance of diaphragm walls equipped as heat exchangers are investigated through finite element modelling. The numerical approach employed is first validated using available experimental data and then applied to perform parametric analyses. Parameters considered in the analysis include panel width, the ratio between the wall and excavation depths, heat transfer pipe spacing, concrete cover, heat-carrier fluid velocity, concrete thermal properties and the temperature difference between the air within the excavation and the soil behind the wall. The results indicate that increasing the number of pipes by reducing their spacing is the primary route to increasing energy efficiency in the short term. However, the thermal properties of the wall concrete and the temperature excess within the excavation space are also important, with the latter becoming the most significant in the medium to long term. This confirms the benefits of exploiting the retaining walls installed for railway tunnels and metro stations where additional sources of heat are available