Verification and Validation of Computational Models for Ultrasonic Testing

The Pacific Northwest National Laboratory (PNNL) is conducting confirmatory research for the U.S. Nuclear Regulatory Commission (NRC) for the verification and validation of computational models used in ultrasonic testing (UT). This paper discusses some of the findings obtained from simple geometrical reflectors in isotropic, fine-grained, homogeneous materials with conventional ultrasonic transducers. A total of 348 ultrasonic raster scans were acquired using pulse-echo conventional probes with different diameters, beam angles, wave modalities, and frequencies. The raster scans contained reflections from machined notches (flaws) of different sizes and orientations. High frequency pencil beam models, and flaw scattering models employing the Kirchhoff and geometric theory of diffraction approximations, were then used to simulate the corresponding experimental measurements. CIVA, a semi-analytical nondestructive evaluation (NDE) simulation platform developed by the French Commissariat à l’Energie Atomique (CEA), was used to run simulations based on the approximation models. The experimental measurements were compared to their modeled counterparts using quantitative metrics obtained from the C-scans, B-scans and A-scans. To address uncertainties in the input parameters to the computational model, parametric studies and sensitivity analyses were conducted on all the relevant inputs. Sources of discrepancies between the experiment and simulated results are discussed in terms of numerical model errors and uncertainties in the experiments and model input parameters

Multi-storey residential buildings and occupant’s behaviour during fire evacuation in the UK: Factors relevant to the development of evacuation strategies

Purpose – The paper aims to investigate human behaviour during fire evacuations in multistorey residential buildings through a focus on the challenges and obstacles that occupants face. Any variations in response behaviours that are relevant to the evacuation strategies/plans in the UK context of occupancy typical of multi-storey buildings in large cities. Design/methodology/approach – A literature review was conducted to identify the factors occupants face and also the decision-making of occupants regarding methods of egress. A mixed research method was adopted using interviews and a questionnaire survey. The findings from the interviews and survey are benchmarked against the information gathered from the literature review. Findings – The paper identifies various challenges that occupants face when evacuating a multi-storey residential building. In terms of the decision-making process, the research results evidence that occupants could be given more information on the evacuation procedures within their specific building. The paper also finds that occupants remain reluctant to use a lift during evacuation in fire event, irrespective of any signage clearly stating that is appropriate to do so in the context of modern lift technology. Originality/Value – This paper contributes to the body of knowledge available on the evacuation of multi-storey buildings located in large cities within the UK, outlining potential areas for future research, focused on providing an insight of the behavioural decisions made by the occupants make when evacuating a building in the event of a fire

5D BIM: an investigation into the integration of quantity surveyors within the BIM process

Purpose This paper aims to investigate the integration of a quantity surveyor (QS) role and practice within the building information modelling (BIM) process to enable better implementation of five-dimensional building information modelling (5D BIM) (D is a result of the data/information dimension integrated in a BIM model). It proposes the use of a “level of development and level of detail” to provide a structured approach for QSs’ integration within the BIM process for an improved implementation of 5D BIM. Design/methodology/approach This paper uses semi-structured interviews with QSs from academic and industry in the UK. A total of 20 face-to-face semi-structured interviews were conducted with two groups (industrial and academic) of ten participants from the West Midlands region in the UK. The interview questions have focussed on gaining perspectives on BIM, BIM and government protocols for the QS profession, expectations and challenges when implementing 5D BIM. Findings The findings show that BIM is perceived differently, and limitation of information obtained from the 3D models in BIM reduce the reliability of 5D BIM for QSs and implementing of 5D BIM needs an understanding of BIM workflow and information requirements. Research limitations/implications Although the findings reveal many of the complexities that face QSs within the BIM process and the shortfalls of 5D BIM technology, the results may lack generalisation. Thus, future research seeks to test the proposed framework further. Practical implications This paper elicits implications of shortfalls that impact the implementation of 5D BIM technology and the complexities that face QSs within the BIM process. Originality/value This paper reveals the need to understand the process of integrating stakeholders and their information requirements for better implementation of technologies within BIM

Urbanization and Meeting the Need for Affordable Housing in Nigeria

Urbanization is an ongoing trend in developed and developing countries. With particular reference to Nigeria, studies have shown that many urban centres have been experiencing rapid and continuous growth over the years, as people tend to migrate from rural areas to urban centres in order to better their living conditions. However, there has been an inadequacy of the necessary infrastructures to meet the needs of the increasing urban populace. Empirical studies have also shown that about 75% of the urban settlers live in slums and improper housing, which is antithetical to human dignity. Therefore, this study aims at exploring the causes, advantages, and disadvantages of urban slum dwelling in Nigeria, and similarly proper possible solutions to the prevailing urbanization challenges in the country. The authors agree that the policy can bring about an effective provision of affordable housing, thereby meeting the needs of housing and helping to solve most of the problems of urbanization in Nigeria. It is recommended that each element of an effective housing policy, as entrenched in the National Housing Policy 2012, should be critically explored towards the delivery of affordable housing, which would in turn go a long way in solving urbanization problems in Nigeria

BIM Role within the Conceptual Design Phase: A Case Study of a UK Construction Project

The application of building information modelling (BIM) during the construction cycle of any development varies. Systematically, the way BIM’s applied during the initial phase will have a direct influence on phases that follow afterwards. Previous research focused on the application of BIM and concentrated on various aspects, which included sustainability or how to overcome the loss of data/information. However, it limited its focus on the application during a specific phase of the project. Analysis outlined both the benefits and barriers of applying BIM during the conceptual design phase. The study suggests that an informed evaluation of the application of BIM during any particular phase should take in consideration different stakeholders’ roles and responsibilities

Estimating the Prevalence of Foodborne Pathogen Campylobacter jejuni in Chicken and Its Control via Sorghum Extracts

Campylobacter jejuni is a Gram-negative bacterium which is considered as the most reported cause of foodborne infection, especially for poultry species. The object of this work is to evaluate the occurrence of C. jejuni in chicken meat as well its control via three types of sorghum extracts (white sorghum (WS), yellow sorghum (YS), and red sorghum (RS)); antibacterial activity, antioxidant power, and cytotoxicity of sorghum extracts were also assessed. It was found that C. jejuni is very abundant in chicken meat, especially breast and thigh. WS extract showed more effectiveness than both yellow and red ones. Lyophilized WS extract offered high total phenolic compounds (TPCs) and total flavonoid compounds (TFCs) of 64.2 ± 0.8 mg gallic acid equivalent (GAE/g) and 33.9 ± 0.4 mg catechol equivalent (CE)/g, respectively. Concerning the antibacterial and antioxidant activities, WS showed high and significant antibacterial activity (p < 0.001); hence, WS displayed a minimum inhibitory concentration (MIC) of 6.25%, and revealed an inhibition zone of 7.8 ± 0.3 mm; it also showed an IC50 at a concentration of 34.6 μg/mL. In our study, different samples of chicken fillet were collected and inoculated with pathogenic C. jejuni and stored at 4 °C. Inoculated samples were treated with lyophilized WS extract at (2%, 4%, and 6%), the 2% treatment showed a full reduction in C. jejuni on the 10th day, the 4% treatment showed a full reduction in C. jejuni on the 8th day, while the 6% treatment showed a full reduction in C. jejuni on the 6th day. Additionally, 2%, 4%, and 6% WS extracts were applied on un-inoculated grilled chicken fillet, which enhanced its sensory attributes. In sum, WS extract is a promising natural preservative for chicken meat with accepted sensory evaluation results thanks to its high antibacterial and antioxidant potentials