Toward an understanding of the impact of production pressure on safety performance in construction operations

It is not unusual to observe that actual schedule and quality performances are different from planned performances (e.g., schedule delay and rework) during a construction project. Such differences often result in production pressure (e.g., being pressed to work faster). Previous studies demonstrated that such production pressure negatively affects safety performance. However, the process by which production pressure influences safety performance, and to what extent, has not been fully investigated. As a result, the impact of production pressure has not been incorporated much into safety management in practice. In an effort to address this issue, this paper examines how production pressure relates to safety performance over time by identifying their feedback processes. A conceptual causal loop diagram is created to identify the relationship between schedule and quality performances (e.g., schedule delays and rework) and the components related to a safety program (e.g., workers’ perceptions of safety, safety training, safety supervision, and crew size). A case study is then experimentally undertaken to investigate this relationship with accident occurrence with the use of data collected from a construction site; the case study is used to build a System Dynamics (SD) model. The SD model, then, is validated through inequality statistics analysis. Sensitivity analysis and statistical screening techniques further permit an evaluation of the impact of the managerial components on accident occurrence. The results of the case study indicate that schedule delays and rework are the critical factors affecting accident occurrence for the monitored project.     

Towards a better understanding of SEA effectiveness in Ireland

The first review of strategic environmental assessment (SEA) effectiveness in Ireland examined how a number of selected case studies performed procedurally. The findings pointed not only to deficiencies in the consideration of alternatives, monitoring and SEA Statements, but also in its capability to lead to more informed and sustainable decisions. Six years on from that review, this paper revisits some of the case studies and appraises non-procedural effectiveness via stakeholder interviews to obtain a more comprehensive account of SEA effectiveness across the life of the reviewed plans. The case studies illustrate a general openness to SEA. Overall, consulted experts agreed that SEA contributes significant knowledge to planning decisions. SEA iterations tend to be more efficient as a result of learning; in some cases, the process led to internal organisational restructuring, facilitating better environmental integration in subsequent plans. There is limited implementation of monitoring across the case studies, so while the review points to positive outcomes of SEA (e.g. new data and knowledge, mitigation by avoidance), it remains to be evidenced whether it ultimately prevents adverse environmental effects.     

Towards understanding the influence of porosity on mechanical and fracture behaviour of quasi-brittle materials: experiments and modelling

In this work, porosity-property relationships of quasi-brittle materials are explored through a combined experimental and numerical approach. In the experimental part, hemihyrate gypsum plaster powder (\(\hbox {CaSO}_{4}\cdot 1/2\hbox {H}_{2}\hbox {O}\)) and expanded spherical polystyrene beads (1.5–2.0 mm dia.) have been mixed to form a model material with controlled additions of porosity. The expanded polystyrene beads represent pores within the bulk due to their light weight and low strength compared with plaster. Varying the addition of infill allows the production of a material with different percentages of porosity: 0, 10, 20, 30 and 31 vol%. The size and location of these pores have been characterised by 3D X-ray computed tomography. Beams of the size of \(20 \times 20 \times 150\) mm were cast and loaded under four-point bending to obtain the mechanical characteristics of each porosity level. The elastic modulus and flexural strength are found to decrease with increased porosity. Fractography studies have been undertaken to identify the role of the pores on the fracture path. Based on the known porosity, a 3D model of each microstructure has been built and the deformation and fracture was computed using a lattice-based multi-scale finite element model. This model predicted similar trends as the experimental results and was able to quantify the fractured sites. The results from this model material experimental data and the lattice model predictions are discussed with respect to the role of porosity on the deformation and fracture of quasi-brittle materials.     

Towards a quantitative understanding of the within-host dynamics of influenza A infections

Although the influenza A virus has been extensively studied, a quantitative understanding of the infection dynamics is still lacking. To make progress in this direction, we designed several mathematical models and compared them with data from influenza A infections of mice. We find that the immune response (IR) plays an important part in the infection dynamics. Both an innate and an adaptive IR are required to provide adequate explanation of the data. In contrast, regrowth of epithelial cells did not seem to be an important mechanism on the time scale of the infection. We also find that different model variants for both innate and adaptive responses fit the data well, indicating the need for additional data to allow further model discrimination.     

Swedish hunters’ safety behaviour and experience of firearm incidents

Since any firearm injury is potentially lethal, it is of great interest to prevent firearm incidents. This study investigated such incidents during hunting and Swedish hunters’ safety behaviour. A 48-item questionnaire was posted to a random sample of 1000 members of the Swedish Association for Hunting and Wildlife Management. The questions considered demographics, hunting experience/hunting habits/safety behaviour/attitudes and experience of careless weapon handling, hunters’ weapons and safety behaviour relating to weapons, health status, firearm incidents and their preventability, and personal comments on the questionnaire. The response rate was almost 50%. The mean age of the responders was 54 years; 5% were females. Almost none (1%) reported hunting under the influence of alcohol. Young age and male sex were positively associated with risk behaviour, although the presence of multiple risk behaviours in the same responder was not common. A very high degree of compliance with Swedish laws regarding weapon storage was reported. One-quarter of the responders had witnessed a firearm incident caused by another hunter, which in most situations did not result in human injury or death. An unsafetied weapon was the most common reported “cause” of these incidents. Experience of a firearm incident was not uncommon and the majority of the responders considered the incident in question to be preventable. This study provides a picture of the possible risk behaviour among hunters and the results suggest that future prevention work should target safer weapon handling.     

Towards an understanding of the intrinsic values of design education

For further progress to be made in design education—particularly in design as a component of general education—it is necessary to articulate its intrinsic values. Two main inter-related areas in which such values might be found are discussed. The first area is the ‘language media’ of design. and the seconds is the modes of thought which relate particularly to design abilities. The latter area draws upon research in the neurosciences which is discovering fundamental differences in the thought modes associated with the two hemispheres of the human brain.     

A longitudinal study of the effectiveness of a multi-media intervention on parents’ knowledge and use of vehicle safety systems for children

Motor-vehicle crashes are the leading cause of death and serious injury for children under the age of 14 in Canada and in the United States despite mandatory use of vehicle restraints since 1977. Using a pre- and post-test design, the present study tests the effectiveness of a multi-media intervention study on parents’ knowledge of car safety seat use for children (0-12 years). The sample included 201 parents from four Ontario cities. Results indicate that parents’ knowledge of when to accurately and safely transition a child to the appropriate car safety seat based on child's age, weight and height was retained at the 1 year post-test for children 4-8 years of age. The rates of correct use of safety seats significantly increased 1 year following the intervention program. Other factors that influenced parent's knowledge included being a parent versus non-parents, gender, income, education, sources of information, and regional location. The results of this study can help guide the development and implementation of future intervention programs and injury prevention policy.     

Exploring the possibility of a common structural model measuring associations between safety climate factors and safety behaviour in health care and the petroleum sectors

The aim of the present study was to explore the possibility of identifying general safety climate concepts in health care and petroleum sectors, as well as develop and test the possibility of a common cross-industrial structural model. Self-completion questionnaire surveys were administered in two organisations and sectors: (1) a large regional hospital in Norway that offers a wide range of hospital services, and (2) a large petroleum company that produces oil and gas worldwide. In total, 1919 and 1806 questionnaires were returned from the hospital and petroleum organisation, with response rates of 55 percent and 52 percent, respectively. Using a split sample procedure principal factor analysis and confirmatory factor analysis revealed six identical cross-industrial measurement concepts in independent samples—five measures of safety climate and one of safety behaviour. The factors’ psychometric properties were explored with satisfactory internal consistency and concept validity. Thus, a common cross-industrial structural model was developed and tested using structural equation modelling (SEM). SEM revealed that a cross-industrial structural model could be identified among health care workers and offshore workers in the North Sea. The most significant contributing variables in the model testing stemmed from organisational management support for safety and supervisor/manager expectations and actions promoting safety. These variables indirectly enhanced safety behaviour (stop working in dangerous situations) through transitions and teamwork across units, and teamwork within units as well as learning, feedback, and improvement. Two new safety climate instruments were validated as part of the study: (1) Short Safety Climate Survey (SSCS) and (2) Hospital Survey on Patient Safety Culture-short (HSOPSC-short). Based on development of measurements and structural model assessment, this study supports the possibility of a common safety climate structural model across health care and the offshore petroleum industry.     

Occupational and lifestyle risk factors in a wellness programme associated with low back injuries in a Midwest university

Employers need a clear understanding of the risk factors associated with low back (LB) injury for future prevention in the workplace. A data mining approach was used to analyse data-sets (Workers' Compensation claims data for employees participating in a health and wellness programme at a Midwestern university) in a retrospective study to summarise the risk factors associated with LB injury. Eight risk factors (age, cause of injury, night shift, fatigue, emotional health, stress level, physical and emotional impairment) are associated with LB injury in the workplace. Age was an effect modifier: lifting, twisting, bending (LTB) and emotional risk factors were associated for employees younger than 40 years old, whereas LTB, slips, trips, falls, and physical risk factors for employees 40 and older. Future considerations discussed not only engineering solutions, but the psychological and lifestyle risk factors associated with LB injury and the need for development of preventative programmes.     

Safety management practices and safety behaviour: Assessing the mediating role of safety knowledge and motivation

Safety management practices not only improve working conditions but also positively influence employees’ attitudes and behaviours with regard to safety, thereby reducing accidents in workplace. This study measured employees’ perceptions on six safety management practices and self-reported safety knowledge, safety motivation, safety compliance and safety participation by conducting a survey using questionnaire among 1566 employees belonging to eight major accident hazard process industrial units in Kerala, a state in southern part of India. The reliability and unidimesionality of all the scales were found acceptable. Path analysis using AMOS-4 software showed that some of the safety management practices have direct and indirect relations with the safety performance components, namely, safety compliance and safety participation. Safety knowledge and safety motivation were found to be the key mediators in explaining these relationships. Safety training was identified as the most important safety management practice that predicts safety knowledge, safety motivation, safety compliance and safety participation. These findings provide valuable guidance for researchers and practitioners for identifying the mechanisms by which they can improve safety of workplace.     

Towards understanding the nanomaterials characteristics of vapor transported CdS in an open end tube

In this study, the evaporation condensation of CdS was carried out in a quartz tube with an open end. The synthesis was carried out on Au coated Si(100) and quartz substrates. The Au coated Si and quartz substrates were put approximately 1 cm and up to 25 cm away from the alumina boat. It was observed that the materials deposited on the substrates in the reactor tube formed with different colors in different regions. The regions were found to be 6–14 cm, 14–18 cm and 18–24 cm away from the center of the alumina boat and were labeled B, C and D, respectively. The morphology, structural and chemical composition of the obtained materials at different regions were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive analysis of X-ray (EDAX), respectively. EDAX analysis revealed the presence of Cd and S with nearly stoichiometric CdS at region B. At region C a pronounced peak of oxygen was observed together with the peaks of Cd and S. At region D the S peak was diminished. XRD examinations revealed the formation of single crystalline phase of hexagonal CdS in region B. Mixed crystalline phases of hexagonal CdS, monoclinic cadmium sulfite, CdSO₃, and cubic CdO were formed in region C. Cubic CdO was formed in region D. The SEM examinations showed that the morphology of CdS was nanowires (NWs) in shape. The morphology of the mixed oxysulfide phase was a mixture between NWs and nanoparticles (NPs). The morphology of CdO was NPs in shape. The optical constants, the thickness and the surface roughness of the prepared nanostructured films were determined by spectroscopic ellipsometry measurements. A model consisted of two layers was used to fit the calculated data to the experimental ellipsometric spectra. The obtained optical constants were compared with those of CdS and CdO obtained by other preparation methods.     

The interaction between design and occupier behaviour in the safety of new homes

The design of new homes includes many safety features intended to protect occupiers from injury or ill health within the home, however the effectiveness of these primary intervention measures is likely to be affected by user behaviour. This study examined the interaction between user activity and dwelling design and how this might affect health and safety. It aimed to identify how people use features within new homes and how this may limit the protection afforded by building design, codes and regulations. Forty, home-based, semi-structured, in-depth interviews and home inspections were conducted with individuals recently inhabiting a new home. A range of behaviours were reported in relation to building features including fire doors, pipes and cables, and loft access, which may lead to increased risk of injury or ill-health. For example, occupiers described interfering with the self-closing mechanisms on fire doors and drilling into walls without considering the location of services. They also reported knowingly engaging in unsafe behaviour when accessing the loft, increasing their risk of falls. The accounts suggest that designers and builders need to give greater consideration to how occupier behaviour interacts with building features so that improvements in both design and occupier education can lead to improved health and safety.     

Towards a better understanding of wood cell wall characterisation with contact resonance atomic force microscopy

Nowadays, the multi-scale modelling of wood has a great need for measurements of structural, chemical and mechanical properties at the lowest level. In this paper, the viscoelastic properties in the layers of a wood cell wall are investigated using the contact resonance mode of an atomic force microscope (CR-AFM). A detailed experimental protocol suitable for obtaining reproducible and quantifiable data is proposed. It is based on three main steps: sample preparation to obtain a good surface state, calibration of the contact modulus using reference samples, and image processing to produce the viscoelastic images. This protocol is applied on chestnut tension wood. The obtained topography and semi-quantitative viscoelastic maps are discussed with respect to the cell wall structure, sample preparation effects, and AFM measurement specificity compared with nanoindentation.     

Towards understanding the morphological,magnetic, optical and electrical properties of MnO<Subscript>2</Subscript> nanowires for magneto-and optoelectronic applications

Mixed solutions of manganese sulfate and potassium permanganate were hydrothermally used to synthesis α-MnO₂ nanowires. Energy dispersive analysis of X-ray revealed the formation of stoichiometric MnO₂ and X-ray diffraction revealed the formation of single crystalline α-MnO₂. Examinations using both SEM and TEM yielded nanowires with diameters ranged from 40 to 50 nm and lengths ranged from 5 to 6 µm. The magnetic properties revealed that the α-MnO₂ NWs exhibit ferromagnetic/antiferromagnetic characteristics at liquid nitrogen and room temperatures. This kind of materials may be find usage in electromagnetic shielding applications. Direct optical band gap of 2.6 eV, that was blue shifted from the bulk value, was reported. Photoluminescence examinations displayed a strong emission peak around 395 nm and broad peak around 477 nm. The α-MnO₂ NWs showed a semiconducting behavior where the resistivity decreased with increasing temperature. Two activation energies were reported; the low temperature activation energy was 0.089 eV and the high temperature activation energy was 0.782 eV. Based on the observed high intensity UV emission peak, the obtained α-MnO₂ NWs may find applications in UV light emitting diodes.     

Safety climate and the Theory of Planned Behavior: Towards the prediction of unsafe behavior

The present study is concerned with the human factors that contribute to violations in aviation maintenance. Much of our previous research in this area has been based on safety climate surveys and the analysis of relations among core dimensions of climate. In this study, we tap into mainstream psychological theory to help clarify the mechanisms underlying the links between climate and behavior. Specifically, we demonstrate the usefulness of Ajzen's (1991, 2001) Theory of Planned Behavior (TPB) to understanding violation behaviors in aircraft maintenance. A questionnaire was administered to 307 aircraft maintenance workers. Constructs measured by the survey included perceptions of management attitudes to safety, own attitudes to violations, intention to violate, group norms, workplace pressures, and violations. A model based on the TPB illustrated hypothetical connections among these variables. Path analyses using AMOS suggested some theoretically justifiable modifications to the model. Fit statistics of the revised model were excellent with intentions, group norms, and personal attitudes combining to explain 50% of the variance in self-reported violations. The model highlighted the importance of management attitudes and group norms as direct and indirect predictors of violation behavior. We conclude that the TPB is a useful tool for understanding the psychological background to the procedural violations so often associated with incidents and accidents.     

Long-term effects of legislation and local promotion of child restraint use in motor vehicles in Sweden

The main objective is to study long-term effects of legislation and promotion of child-restraint use in motor vehicles. Subgoals are to describe the level of restraint use in cars and changes in mortality and morbidity patterns in regard to differences among age groups and geographical areas (morbidity). The study areas were; ‘The First Four’, ‘The Six Counties’, ‘The Rest of Sweden’, and ‘Sweden as a whole’, and the population were two age groups — 0–6 and 7–14 years. The incidence of restraint use comes from observations of car-seat-belt usage. Outcome evaluation was based on hospital-discharge data 1978–1996 and mortality statistics 1970–1996. The level of restraint use for children in the front seat was 97% in 1988 and was equal to 1995. Mortality data shows a decrease of 2.8% on an average per year, 76% over the study period. A significant change over time in the two intervention areas was shown (annual changes of −2.8 and −1.8%), but not in the rest of Sweden. The local authorities that started early with preventive programs, such as safety seat loan schemes and those having an organised safety-promotion program showed a much better improvement than the rest of Sweden. There is a need for appropriate information for local action on childhood injury prevention to accompany national legislation.     

Use of decision criteria based on expected values to support decision-making in a production assurance and safety setting

We consider decision problems related to production assurance and safety. The issue is to what extent we should use decision criteria based on expected values, such as the expected net present value (E[NPV]) and the expected cost per expected number of saved lives (ICAF), to guide the decision. Such criteria are recognised as practical tools for supporting decision-making under uncertainty, but is uncertainty adequately taken into account by these criteria? Based on the prevailing practice and the existing literature, we conclude that there is a need for a clarification of the rationale of these criteria. Adjustments of the standard approaches have been suggested to reflect risks and uncertainties, but can cautionary and precautionary concerns be replaced by formulae and mechanical procedures? These issues are discussed in the present paper, particularly addressing the company level. We argue that the search for such formulae and procedures should be replaced by a more balanced perspective acknowledging that there will always be a need for management review and judgment beyond the realm of the analyses. Most of the suggested adjustments of the E[NPV] and ICAF approaches should be avoided. They add more confusion than value.     

Natural formation of a protective layer on copper and copper brazing in domestic water: structural characterization and electrochemical behaviour

The coupling Cu/Cu-P brazing, which is that most employed in domestic water supply pipes, has been investigated. Potentiostatic corrosion experiments were performed in domestic water under different conditions. It appears that the brazing has a better resistance than copper. The nature of the films formed at the sample surfaces was determined by various analysis techniques and the thicknesses were measured by ellipsometry. It was observed that it was the difference in composition of the films, formed at copper and brazing surfaces, which allowed the Cu-P brazing to become more noble than copper. The relatively thicker film formed on brazing, appears to contain mainly calcium carbonate and sulphate which grow epitaxially on calcium phosphate (hydroxyapatite or brishite). The corrosion resistance of the studied brazing was not only related to the galvanic coupling copper/brazing, but also depended on other parameters, mainly the water-flow velocity.