Search results

This paper aims to report a synopsis of a recent systematic review of the literature regarding the effectiveness of workplace physical activity interventions, commissioned by the National Institute for Health and Clinical Excellence (NICE).

A search for English‐language papers published between 1996 and 2007 was conducted using 12 relevant databases and associated grey literature. Search protocols and analysis regarding study quality as recommended by NICE were utilised. Key inclusion criteria were, workplace intervention aiming to increase physical activity, intervention aimed at working adults, intervention initiated/endorsed by the employer, physical activity outcome. Thirty‐three studies (38 papers) met the inclusion criteria and were independently reviewed (checked by two reviewers) with a narrative synthesis of findings.

Fourteen studies were graded as high quality or good quality. Evidence from previous systematic reviews was inconclusive. Data regarding the effectiveness of stair walking interventions was limited and intervention effects were short‐lived. Three public sector studies provided evidence that workplace walking interventions using pedometers can increase daily step counts. One good quality study reported a positive intervention effect on walking to work behaviour (active travel) in economically advantaged female employees. There was strong evidence that workplace counselling influenced physical activity behaviour. There is a dearth of evidence for small and medium enterprises.

Due to the necessary UK focus and time constraints, only studies from Europe, Australia, New Zealand and Canada were included.

The paper shows that there is a growing evidence base that workplace physical activity interventions can positively influence physical activity behaviour.

In a circular economy, the goal is to keep materials values in the economy for as long as possible. For the construction industry to support the goal of the circular economy, there is the need for materials reuse. However, there is little or no information about the amount and quality of reusable materials obtainable when buildings are deconstructed. The purpose of this paper, therefore, is to develop a reusability analytics tool for assessing end-of-life status of building materials.

A review of the extant literature was carried out to identify the best approach to modelling end-of-life reusability assessment tool. The reliability analysis principle and materials properties were used to develop the predictive mathematical model for assessing building materials performance. The model was tested using the case study of a building design and materials take-off quantities as specified in the bill of quantity of the building design.

The results of analytics show that the quality of the building materials varies with the building component. For example, from the case study, at the 80th year of the building, the qualities of the obtainable concrete from the building are 0.9865, 0.9835, 0.9728 and 0.9799, respectively, from the foundation, first floor, frame and stair components of the building.

As a contribution to the concept of circular economy in the built environment, the tool provides a foundation for estimating the quality of obtainable building materials at the end-of-life based on the life expectancy of the building materials.

The purpose of this paper is to study the adaptability of the tracked robot in complex working environment. It proposes an angle-changeable tracked robot with human–robot interaction in unstructured environment. The study aims to present the mechanical structure and human–robot interaction control system of the tracked robot and analyze the static stability of the robot working in three terrains, i.e. rugged terrain, sloped terrain and stairs.

The paper presents the mechanical structure and human–robot interaction control system of the tracked robot. To prevent the detachment of the tracks during obstacle navigation, a new type of passively adaptive device based on the relationship between the track’s variable angle and the forces is presented. Then three types of rough terrain are chosen to analyze the static stability of the tracked robot, i.e. rugged terrain, sloped terrain and stairs.

This paper provides the design method of the tracked robot. Owing to its appropriate dimensions, good mass distribution and limited velocity, the tracked robot remains stable on the complex terrains. The experimental results verify the effectiveness of the design method.

The theoretical analysis of this paper provides basic reference for the structural design of tracked robots.

The purpose of this paper is to identify and compare cost and carbon critical elements of two office buildings, and to help achieve an optimum balance between the capital cost (CC) and embodied carbon (EC) of buildings.

Case study approach was employed to study cost and carbon critical elements of two office buildings as it allows an in-depth and holistic investigation. Elemental estimates of CC and EC were prepared from BoQs of the two buildings by obtaining rates from the UK Building Blackbook. Pareto principle (80:20 rule) was used to identify carbon and cost critical elements of the two buildings, and the significance hierarchies of building elements were compared.

Substructure, frame and services were identified as both carbon and cost critical elements responsible for more than 70 per cent of the total CC and EC of both buildings. Stairs and ramps, internal doors and fittings, furnishings and equipment were identified to be the least carbon- and cost-significant elements contributing less than 2 per cent of total CC and EC in both buildings. The hierarchy of cost and carbon significance varies between buildings due to the difference in the specification and design.

The increasing significance of dual currency (cost and carbon) demands cost and carbon management during the early stages of projects. Hence, this paper suggests that focusing on carbon and cost-intensive building elements is a way forward to keep both cost and carbon under control during the early stages of projects.

This paper seeks to redress the omission in recent literature on the influence of project strategic, site related and design related variables on the cost of construction. It presents, in part, the results of an investigation into the influence of 41 independent variables on both construction cost and client cost, concentrating on design related variables. Data were collected from 286 construction projects in the United Kingdom and correlation and test for differences were used to determine the relationships that exist between the dependent and independent variables. The analysis ascertains the cost ranking of many design related variables and establishes other relationships which exist within the data, confirming many of the relationships that had been anticipated from the literature. It also established the ordinal sequence of several nominal variables. These data, therefore, can be confidently used to develop models of the total cost of construction as verified by the development of both regression analysis and neural network cost models

Trust is considered instrumental for economic growth, successful operation of public institutions and social cohesion. We explore how public trust in Icelandic institutions has developed during the recent tumultous financial times, including the failure of the Icelandic banking sector. Using data from Gallup-Iceland’s annual survey of individuals’ trust in institutions, we show that trust in general, and particularly towards political and financial institutions, evaporates following the crisis year of 2008. Although trust varies significantly among different demographic groups, the trend shows how the road to recovering trust in Icelandic institutions post-crisis has proven to be challenging and drawn-out. Apart from law-enforcement agencies, which were relatively unscathed by the financial calamities, no institution has managed to escape the drop in trust, nor have they re-established the pre-crisis level of trust in the minds of the public nearly a decade after the crisis. A notable personal post-crisis exception is the recently elected President of Iceland who has managed to improve trust in his office by the highest margin of all 15 public offices and institutions examined.

This paper aims to investigate the effect of partially blocking the cathode channel with the stair arrangement of obstacles on the performance of a proton exchange membrane fuel cell.

A numerical study is conducted by developing a three-dimensional computational fluid dynamics model.

As the angle of the stair arrangement increases, the performance of the fuel cell is reduced and the pressure drop is decreased. The use of four stair obstacles with an angle of 0.17° leads to higher power density and a lower pressure drop compared to the case with three rectangular obstacles of the same size and maximum height. The use of four stair obstacles with an angle of 0.34° results in higher power density and lower pressure drop compared to the case with two rectangular obstacles of the same size and maximum height.

Using the stair arrangement of obstacles as an innovation of the present work, in addition to improving the fuel cell’s performance, creates a lower pressure drop than the simple arrangement of obstacles.

The paper aims to raise awareness in the industry of design automation tools, especially in early design phases, by demonstrating along a case study the seamless integration of a prototypically implemented optimization, supporting design space exploration in the early design phase and an in operational use product configurator, supporting the drafting and detailing of the solution predominantly in the later design phase.

Based on the comparison of modeled as-is and to-be processes of ascent assembly designs with and without design automation tools, an automation roadmap is developed. Using qualitative and quantitative assessments, the potentials and benefits, as well as acceptance and usage aspects, are evaluated.

Engineers tend to consider design automation for routine tasks. Yet, prototypical implementations support the communication and identification of the potential for the early stages of the design process to explore solution spaces. In this context, choosing from and interactively working with automatically generated alternative solutions emerged as a particular focus. Translators, enabling automatic downstream propagation of changes and thus ensuring consistency as to change management were also evaluated to be of major value.

A systematic validation of design automation in design practice is presented. For generalization, more case studies are needed. Further, the derivation of appropriate metrics needs to be investigated to normalize validation of design automation in future research.

Integration of design automation in early design phases has great potential for reducing costs in the market launch. Prototypical implementations are an important ingredient for potential evaluation of actual usage and acceptance before implementing a live system.

There is a lack of systematic validation of design automation tools supporting early design phases. In this context, this work contributes a systematically validated industrial case study. Early design-phases-support technology transfer is important because of high leverage potential.

The purpose of this paper is to devise an analytical approach to calculate conductor winding losses, considering multiple contributing aspects simultaneously. These include the geometric configuration of coil windings, frequency of the electric current and the dependency on the coil temperature, derived studying a coupled fluid–solid model considering the cooling system characteristics. The obtained results allow identifying power loss trends according to such system variables as coolant inlet temperature or overall flow rate of the motor.

An easy-to-use coupled analytical approach is applied, which is suitable for rapid estimations of the impact of parameter variation on the resulting conductor winding power losses that facilitates decision-making in the design process of electric aircraft engines.

In the considered cooling parameters, the overall conductor winding power losses vary approximately between 6 kW and 7.2 kW. More than 95 per cent of this loss is because of direct current losses. These losses cause the variation in maximal coil temperature ranging between 115°C and 170°C.

The SP260D motor is set and was currently tested in Extra 330. It recently broke two world records.

One of the current trends in aircraft engineering is electric aircraft. Advantages of electric aircraft include improved manoeuvrability because of greater torque from electric motors, increased safety because of decreased chance of mechanical failure, less risk of explosion or fire in the event of a collision and less noise. There will be environmental and cost benefits associated with the elimination of dependency on fossil fuels and resultant emissions.

The use of a novel fluid–solid interaction model for predicting conductor winding power loss of the SP260D electric aircraft motor has not been done earlier. A novel alternative derivation of the widely applied Dowell’s formula (Dowell, 1966) is presented for the estimation of proximity losses in square winding conductors.

In recent years, the number of high-rise buildings in Malaysia has been increasing. Therefore, it is essential to take evacuation into consideration especially for emergency conditions such as fire, explosion and natural disasters. This research aims to evaluate the effectiveness of the escape time in typical Malaysian high-rise residential buildings.

This work comprises simulation on three buildings around the Selangor area in Malaysia. Quantitative methodology is adopted using Pathfinder software to simulate the evacuation process and time of the three typical Malaysian high-rise residential buildings. Four parameters were studied namely, the occupant load density, walking speed of first and last occupants, average of evacuation time per floor for the three buildings and effect of placement of emergency staircase on travel time.

Findings show that 12 m² which is double the allowable occupants' density in Malaysia increases evacuation time by 67.9% while the placement of the emergency staircase on the left and middle section of a building significantly affects the evacuation time by 21.2%. In conclusion, from the simulation studies, it is recognized that a higher occupant's density affects the evacuation time.

This work could provide information on escape time for future construction of high-rise buildings in Malaysia. Hence, the specification and design of buildings could be reviewed based on the results obtained from this simulation. This information could be beneficial to the building regulators and developers thus enhancing the knowledge of building constructor and possible issues in the design of staircases, corridors and height of buildings.