Introducing the RZ model for definition and optimization of the boundary of low emission zones

Poor urban air quality is one of the most pressing environmental problems and the rapid growth in the number of motor vehicles is a major contributor to it. To tackle this problem, Low Emission Zones (LEZ) were introduced and they have been applied in many of the mega cities around the world. Yet, a scientific approach to design the boundaries of LEZs is missing. This study develops an innovative model to address this gap, using total Vehicle Kilometers Traveled (VKT) as the basis. The model allows defining and/or optimizing the LEZ boundaries. It is applied for Tehran metropolitan area, as a case study, and the results show the optimality of the existing LEZ boundaries, however, they challenge the efficiency of the proposed policies on modifying current boundaries

Performance-based contracting in the construction sector

Construction procurement is complex and there is a very wide range of options available to procurers. Inappropriate choices about how to procure may limit practical opportunities for innovation. In particular, traditional approaches to construction procurement set up many obstacles for technology suppliers to provide innovative solutions. This is because they are often employed as sub-contractors simply to provide and install equipment to specifications developed before the point at which they become involved in a project. A research team at the University of Reading has developed a procurement framework that comprehensively defines the various options open to procurers in a more fine-grained way than has been known in the past. This enables informed decisions that can establish tailor-made procurement approaches that take into account the needs of specific clients. It enables risk and reward structures to be aligned so that contracts and payment mechanisms are aligned precisely with what a client seeks to achieve. This is not a “one-size-fits-all” approach. Rather, it is an approach that enables informed decisions about how to organize individual procurements that are appropriate to particular circumstances, acknowledging that they differ for each client and for each procurement exercise. Within this context, performance-based contracting (PBC) is explored in terms of the different ways in which technology suppliers within constructed facilities might be encouraged and rewarded for the kinds of innovation sought by the ultimate clients. Examples from various industry sectors are presented, from public sector and from private sector, with a commentary about what they sought to achieve and the extent to which they were successful. The lessons from these examples are presented in terms of feasibility in relation to financial issues, governance, economics, strategic issues, contractual issues and cash flow issues for clients and for contractors. Further background documents and more detailed readings are provided in an appendix for those who wish to find out more

Role conflict in project team dynamics

Project team dynamics may be affected by mismatches between formal and informal sources of expectations. Conflicting or unclear expectations have not yet been studied closely in construction projects. Using role theory, the effect of such phenomena on project team dynamics was studied in construction projects. Most research into role theory relies on survey data; however, this study takes a qualitative approach. For a public project, contracts were studied, project meetings were observed, and semi-structured interviews with the major members of the design team were carried out to identify formal and informal sources of role expectations. Analysis focused on the misalignment of these sources. A model was developed to help explain project team dynamics and the interaction of formal and informal sources of role expectations. Findings reveal that underspecified roles and responsibilities within contracts and plans of works effected role interactions and ultimately team dynamics

The interplay between formal and informal elements in analysing situations of role conflict among construction participants

The interplay of formal and informal factors in construction teams influences the enactment of roles and the individuals who fulfil those roles. With a specific focus on a phenomenon called role conflict, the aim is to explore if and how the interaction of formal and informal elements would lead to situations of role conflict. This phenomenon proved to lead to frustration, tension and employee burnout. An analytical model of role interaction was developed, which disentangles formal and informal elements that shape role interactions. Qualitative data was collected through semi-structured interviews, project documents and observations. Four cases of role conflict are presented here. Contract, as a formal element, and participant’s values and interests, as informal elements, appeared to be the most important factor shaping participants’ expectations and behaviours. The analysis in this study showed that if a participant who faces role conflict is able to influence the formal elements in favour of his or her informal elements, then he or she may experience less frustration. At a more general level, the results suggest that increasing formality can increase participants’ frustration, which then would decrease the likelihood of collaboration. As the theoretical contribution, this research extends organizational role theory to deal with informal and formal aspects. Taking into account formal sources enables the study of how roles are institutionally governed while including informal sources allows for the idea that some of the aspects of the role, even in the context of work role, are socially constructed

Weather-wise: a weather-aware planning tool for improving construction productivity and dealing with claims

The influence of unforeseen, extreme weather in construction works usually impacts productivity, causes significant project delays and constitutes a frequent source of contractor’s claims. However, construction practitioners cannot count on sound methods for mediating when weather-related claims arise, nor harnessing the influence of weather variability in construction projects. Building on the few most recent quantitative studies identifying those key weather agents and levels of intensity that affect some standard building construction activities, a new stochastic model that processes and replicates the spatio-temporal variability of combined weather variables is proposed. This model can help anticipate weather-related project duration variability; improving construction productivity by selecting the best project start date; and objectively evaluating weather-related claims. A two-building construction case study using different Spanish locations is used to demonstrate the model. The results showed that ignoring the influence of weather can lead to an extension of 5-20% longer project duration compared to planned

Role conflict and role ambiguity in construction projects

Role conflict happens when a person faces different and incompatible expectations regarding a particular social status which they occupy. The literature on role conflict is reviewed for a better understanding of project dynamics in construction teams. The discussion focuses on issues surrounding the miscommunication of role expectations and tensions owing to differences in expectations of the same role. This ongoing doctoral study involves a qualitative research design, based on interviews with practicing professionals. Analysis will focus on the relation between formal expectations, as evidenced in contracts and other types of written communication, and informal expectations as observed from the interviews. Insights from the literature review suggest: 1. that the differences between formal and informal expectations is a major sources of role conflict in construction teams and 2. that this effect is exacerbated by the failure of team members to recognise it and take it into account

Green synthesis of zinc oxide nanoparticles: a comparison

Green synthesis of nanoparticles by biological systems especially plant extracts has become an emerging field in nanotechnology. In this study, zinc oxide nanoparticles were synthesized using Laurus nobilis L. leaves aqueous extract and two different zinc salts (zinc acetate and zinc nitrate) as precursors. The synthesized nanoparticles were characterized by Ultraviolet–Visible spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction analysis (XRD), Energy-Dispersive X-ray analysis (EDX) and Scanning Electron Microscopy (SEM). UV–Vis spectra showed typical absorption peaks in around 350 nm due to their large excitation binding energy at room temperature. Chemical bond formations of zinc oxide were confirmed by FT-IR analyses. XRD results revealed the formation of hexagonal wurtzite structure, and SEM analyses showed spherical shape with the average size (21.49, 25.26) nm for the synthesized nanoparticles by zinc acetate and zinc nitrate respectively. EDX analyses confirmed high purity for the synthesized nanoparticles

Project planning and scheduling using system dynamics for dealing with complexity on construction projects

Projects planning and scheduling in the construction industry, and also in other industries, is reflected by many different types of research and empirical to be critical to project success. Traditional project planning methods, for instance, CPM, are used and still uses as managerial assistance in different industries of construction, IT, defence and oil and gas projects. However, many projects developed by these methods are failed to predict and deliver the final duration of projects at completion point. The results are deterministic and unreliable to deliver the project objectives. This is originated from ignorance of understanding the cause and effects relationships of different internal and external elements. Increased complexity is one of the fundamental issues causing project failure. Planning systems must deal with increased complexity, which traditional systems were never designed for. Projects can be technically complex, organisationally complex, and environmentally complex. This research uses a bottom-up approach and designed to understand and develop a conceptual framework to map complexity and improve the flow of information in the project planning stage of construction projects in Iran. The expectation is to understand the realistic view of project scheduling considering projects complexity and uncertainties and project factors interactions as a result. This is based on project scheduling with simulations using system dynamics, documents and feedback of questionnaires from the construction sector of Iran. The questionnaires are used to justify the proposed conceptual framework. The proposed framework provides an enhanced sympathetic of project behavior. The contribution is to understand the causes of complexity in construction projects to overcome the shortcoming of tradition project planning and scheduling methods

Dealing with weather-related claims in construction contracts: a new approach

Project execution is often delayed by extreme and unforeseen weather conditions. This is because extreme weather usually causes work disruption, waste of resources, significant project delays and, eventually, financial losses for both the contractor and the project owner. Construction contracts generally include weather-related clauses addressing when, and to what extent, the responsibilities and consequences of adverse weather are to be shared or compensated. However, setting clear and objective limits for abnormal weather is problematic, starting with the lack of agreement about which weather conditions can be considered as "normal" or "average”. Research on the influence of weather on construction productivity is scarce and underdeveloped. Therefore, practitioners cannot count on sound methods to mediate in and evaluate weather-related contract disputes. In these situations, claims are likely to arise and escalate. A stochastic model for objectively evaluating the weather influence during the execution stage is proposed. This model allows actual weather to be compared to historical data in a way that provides an objective assessment of the extent to which the adverse weather was (or not) exceptional. A case study of a fictional project is used to show its implementation. This is the first tool of its kind to address this concern with a straightforward, holistic and quantitative approach