Three embedded techniques for finite element heat flow problem with embedded discontinuities

The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-017-1382-7The present paper explores the solution of a heat conduction problem considering discontinuities embedded within the mesh and aligned at arbitrary angles with respect to the mesh edges. Three alternative approaches are proposed as solutions to the problem. The difference between these approaches compared to alternatives, such as the eXtended Finite Element Method (X-FEM), is that the current proposal attempts to preserve the global matrix graph in order to improve performance. The first two alternatives comprise an enrichment of the Finite Element (FE) space obtained through the addition of some new local degrees of freedom to allow capturing discontinuities within the element. The new degrees of freedom are statically condensed prior to assembly, so that the graph of the final system is not changed. The third approach is based on the use of modified FE-shape functions that substitute the standard ones on the cut elements. The imposition of both Neumann and Dirichlet boundary conditions is considered at the embedded interface. The results of all the proposed methods are then compared with a reference solution obtained using the standard FE on a mesh containing the actual discontinuity.Peer ReviewedPostprint (author's final draft

A robust algorithm for implicit description of immersed geometries within a background mesh

The paper presents a robust algorithm, which allows to implicitly describe and track immersed geometries within a background mesh. The background mesh is assumed to be unstructured and discretized by tetrahedrons. The contained geometry is assumed to be given as triangulated surface. Within the background mesh, the immersed geometry is described implicitly using a discontinuous distance function based on a level-set approach. This distance function allows to consider both, “double-sided” geometries like membrane or shell structures, and “single-sided” objects for which an enclosed volume is univocally defined. For the second case, the discontinuous distance function is complemented by a continuous signed distance function, whereas ray casting is applied to identify the closed volume regions. Furthermore, adaptive mesh refinement is employed to provide the necessary resolution of the background mesh. The proposed algorithm can handle arbitrarily complicated geometries, possibly containing modeling errors (i.e., gaps, overlaps or a non-unique orientation of surface normals). Another important advantage of the algorithm is the embarrassingly parallel nature of its operations. This characteristic allows for a straightforward parallelization using MPI. All developments were implemented within the open source framework “KratosMultiphysics” and are available under the BSD license. The capabilities of the implementation are demonstrated with various application examples involving practice-oriented geometries. The results finally show, that the algorithm is able to describe most complicated geometries within a background mesh, whereas the approximation quality may be directly controlled by mesh refinement.Peer ReviewedPostprint (published version

WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Adverse Birth Outcomes

Introduction: Three recent systematic reviews suggested a relationship between noise exposure and adverse birth outcomes. The aim of this review was to evaluate the evidence for the World Health Organization (WHO) noise guidelines and conduct an updated systematic review of environmental noise, specifically aircraft and road traffic noise and birth outcomes, such as preterm birth, low birth weight, being small for gestational age and congenital malformations. Materials and methods: We reviewed again all the papers on environmental noise and birth outcomes included in the previous three systematic reviews and conducted a systematic search on noise and birth outcomes to update previous reviews. Web of Science, PubMed and Embase electronic databases were searched for papers published between June 2014 (end date of previous systematic review) and December 2016 using a list of specific search terms. Studies were also screened in the reference list of relevant reviews/articles. Further inclusion and exclusion criteria for the studies provided by the WHO expert group were applied. Risk of bias was assessed according to criteria from the Newcastle-Ottawa quality assessment scale for case-control and cohort studies. Finally, we applied the GRADE principles to our systematic review in a reproducible and appropriate way for judgment about quality of evidence. Results: In total, 14 studies are included in this review, six studies on aircraft noise and birth outcomes, five studies (two with more or less the same population) on road traffic noise and birth outcomes and three related studies on total ambient noise that is likely to be mostly traffic noise that met the criteria. The number of studies on environmental noise and birth outcomes is small and the quality of evidence generally ranges from very low to low, particularly in case of the older studies. The quality is better for the more recent traffic noise and birth outcomes studies. As there were too few studies, we did not conduct meta-analyses. Discussion: This systematic review is supported by previous systematic reviews and meta-analyses that suggested that there may be some suggestive evidence for an association between environmental noise exposure and birth outcomes, although they pointed more generally to a stronger role of occupational noise exposure, which tends to be higher and last longer. Very strict criteria for inclusion and exclusion of studies, performance of quality assessment for risk of bias, and finally applying GRADE principles for judgment of quality of evidence are the strengths of this review. CONCLUSIONS: We found evidence of very low quality for associations between aircraft noise and preterm birth, low birth weight and congenital anomalies, and low quality evidence for an association between road traffic noise and low birth weight, preterm birth and small for gestational age. Further high quality studies are required to establish such associations. Future studies are recommended to apply robust exposure assessment methods (e.g., modeled or measured noise levels at bedroom facade), disentangle associations for different sources of noise as well as daytime and nighttime noise, evaluate the impacts of noise evens (that stand out of the noise background), and control the analyses for confounding factors, such as socioeconomic status, lifestyle factors and other environmental factors, especially air pollution

Engineering, procurement and construction (EPC): what are the variables that impact the success of the projects currently running in Brazil?

Em tempos de grandes obras (eventos esportivos 2014 e 2016, plano de aceleração do crescimento do governo federal e setor petroquímico), este artigo busca identificar variáveis que contribuem para o sucesso dos projetos de engenharia e construção executados atualmente no Brasil. O relacionamento entre a presença de certas variáveis independentes e o sucesso dos projetos foi testado em termos de um conjunto de indicadores de desempenho em projetos, que envolve: conformidade com orçamento (custo); cronograma (tempo); especificações técnicas (requisitos do produto/serviço); e atendimento às demandas dos clientes. Foi analisado o efeito de três variáveis de entrada: apoio da alta administração, existência de um gerente de projetos dedicado e a presença de uma estrutura formal de gerenciamento de projetos (Escritório de Gerenciamento de Projetos). Para testar as hipóteses da pesquisa, foi desenvolvido um estudo empírico, adotando-se uma abordagem quantitativa, com um levantamento (“survey”) junto a 120 profissionais relacionados ao setor de engenharia e construção. Considerando-se o triângulo de ferro (prazo, custo e qualidade), identificou-se que há relação entre a presença de um gerente de projeto dedicado e o cumprimento do orçamento planejado e há relação entre a presença de um gerente de projeto dedicado e o cumprimento dos prazos dos projetos executados. Contudo, a visão ampliada de qualidade, envolvendo também a satisfação do cliente, não foi confirmadaIn times of major construction projects (the sports events of 2014 and 2016, the economic plan of growth acceleration and petrochemical sector), this paper aims at identifying variables that contribute to the success of engineering and procurement construction (EPC) projects currently being carried out in Brazil. The relationship between the presence of certain independent variables and project success was tested by a group of project performance indexes, such as: budget compliance (cost); timetable (time); technical specifications (goods/ services requisites); and costumers’ demand meeting. The effect of the independent variables was analyzed by: top management support, existence of a dedicated project manager and the presence of a formal project management structure (Project Management Office - PMO). To test for the hypothesis of this research proposal, an empirical study was developed implementing a quantitative-based approach in which 120 professionals of the EPC industry were surveyed. Considering the iron triangle (time, cost and quality), it was identified that there are relationship between the presence of a dedicated project manager and the fulfillment of the planned budget, as well the compliance with the project timetable. However, the broader quality approach that involves also costumer satisfaction is yet to be confirme

A sibling study of whether maternal exposure to different types of natural space is related to birth weight

Background: Birthweight is an important determinant of health across the life course. Maternal exposure to natural space has been linked to higher birthweight, but stronger evidence of a causal link is needed. We use a quasi-experimental sibling study design to investigate if change in the mother’s exposure to natural space between births was related to birthweight, in urban Scotland. Methods: Amount (% area) of total natural space, total accessible (public) natural space, parks, woodlands and open water within 100 m of the mother’s postcode was calculated for eligible births (n = 40 194; 1991–2010) in the Scottish Longitudinal Study (a semi-random 5.3% sample of the Scottish population). Associations between natural space and birthweight were estimated, using ordinary least squares and fixed effects models. Results: Birthweight was associated with the total amount of natural space around the mother’s home (+8.2 g for interquartile range increase), but was unrelated to specific types of natural space. This whole-sample relationship disappeared in the sibling analysis, indicating residual confounding. The sibling models showed effects for total natural space with births to women who already had children (+20.1 g), and to those with an intermediate level of education (+14.1 g). Conclusions: The importance of total natural space for birthweight suggests that benefits can be experienced near to as well as within natural space. Ensuring expectant mothers have good access to high quality neighbourhood natural space has the potential to improve the infant’s start in life, and consequently their health trajectory over the life course

Mental Health Benefits of Long-Term Exposure to Residential Green and Blue Spaces: A Systematic Review

Many studies conducted during the last decade suggest the mental health benefits of green and blue spaces. We aimed to systematically review the available literature on the long-term mental health benefits of residential green and blue spaces by including studies that used standardized tools or objective measures of both the exposures and the outcomes of interest. We followed the PRISMA statement guidelines for reporting systematic reviews and meta-analysis. In total 28 studies were included in the systematic review. We found limited evidence for a causal relationship between surrounding greenness and mental health in adults, whereas the evidence was inadequate in children. The evidence was also inadequate for the other exposures evaluated (access to green spaces, quality of green spaces, and blue spaces) in both adults and children. The main limitation was the limited number of studies, together with the heterogeneity regarding exposure assessment. Given the increase in mental health problems and the current rapid urbanization worldwide, results of the present systematic review should be taken into account in future urban planning. However, further research is needed to provide more consistent evidence and more detailed information on the mechanisms and the characteristics of the green and blue spaces that promote better mental health. We provide recommendations for future studies in order to provide consistent and evidence-based recommendations for policy makers

An integrative approach to evaluating the implementation of social and emotional learning and gender-based violence prevention education

Evaluation studies often use stand-alone and summative assessment strategies to examine the impacts of Social and Emotional Learning (SEL) and Gender-based Violence (GBV) prevention education programs. However, implementation research is yet to offer an integrative framework that can be used to investigate the implementation drivers that lead to the uptake of programs that pursue SEL and GBV prevention agendas. We address this gap in research by presenting a framework developed to investigate factors affecting the implementation of the Resilience, Rights and Respectful Relationships program, an SEL and GBV prevention education program developed for primary and secondary schools in the state of Victoria, Australia. Drawing upon and advancing a conceptual framework for implementation fidelity proposed by Carroll and colleagues we discuss the iterative process designed to investigate the individual, school and system level factors within the wider political and ideological setting(s) of the program that impact on its implementation. Within this iterative process, we highlight the need to focus on ‘the ecology of relations’ that exists between various implementation elements, and their possible mediating impact on program delivery, uptake and outcomes.peer-reviewe

Teaching for Democracy: Towards an Ecological Understanding of Pre-Service Teachers’ Beliefs

Due to the significance of beliefs in giving direction to the activities of educators, the present study examined the beliefs of 12 Iranian pre-service teachers about democratic education. Overall, the findings of focus group discussion and semi-structured interviews pointed to a technicist and often an apolitical view of teaching held by most of the participants. While these findings can be explained with reference to a constellation of factors in Iran’s education policy, this study concludes by pointing to the need for an ecological understanding of teachers’ belief systems. Such an approach identifies teachers’ agency embedded within a matrix of structural possibilities and constraints as an important contributor to their internalized beliefs

Urban and Transport Planning Related Exposures and Mortality: A Health Impact Assessment for Cities

BACKGROUND: By 2050, almost 70% of people globally are projected to live in urban areas. As the environments we inhabit affect our health, urban and transport designs that promote healthy living are needed. OBJECTIVE: We estimated the number of premature deaths preventable under compliance with international exposure recommendations for physical activity (PA), air pollution, noise, heat, and access to green spaces. METHODS: We developed and applied the Urban and TranspOrt Planning Health Impact Assessment (UTOPHIA) tool to Barcelona. Exposure estimates and mortality data were available for 1357361 residents. We compared recommended with current exposure levels. We quantified the associations between exposures and mortality and calculated population attributable fractions to estimate the number of premature deaths preventable. We also modeled life-expectancy and economic impacts. RESULTS: We estimated that annually almost 20% of mortality could be prevented if international recommendations for performance of PA, exposure to air pollution, noise, heat, and access to green space were complied with. Estimations showed that the biggest share in preventable deaths was attributable to increases in PA, followed by exposure reductions in air pollution, traffic noise and heat. Access to green spaces had smaller effects on mortality. Compliance was estimated to increase the average life expectancy by 360 (95% CI: 219, 493) days and result in economic savings of 9.3 (95% CI: 4.9; 13.2) billion euro per year. CONCLUSIONS: PA factors and environmental exposures can be modified by changes in urban and transport planning. We emphasize the need for (1) the reduction of motorized traffic through the promotion of active and public transport and (2) the provision of green infrastructure, which are both suggested to provide PA opportunities and mitigation of air pollution, noise, and heat

A framework for developing finite element codes for multi- disciplinary applications

The world of computing simulation has experienced great progresses in recent years and requires more exigent multidisciplinary challenges to satisfy the new upcoming demands. Increasing the importance of solving multi-disciplinary problems makes developers put more attention to these problems and deal with difficulties involved in developing software in this area. Conventional finite element codes have several difficulties in dealing with multi-disciplinary problems. Many of these codes are designed and implemented for solving a certain type of problems, generally involving a single field. Extending these codes to deal with another field of analysis usually consists of several problems and large amounts of modifications and implementations. Some typical difficulties are: predefined set of degrees of freedom per node, data structure with fixed set of defined variables, global list of variables for all entities, domain based interfaces, IO restriction in reading new data and writing new results and algorithm definition inside the code. A common approach is to connect different solvers via a master program which implements the interaction algorithms and also transfers data from one solver to another. This approach has been used successfully in practice but results duplicated implementation and redundant overhead of data storing and transferring which may be significant depending to the solvers data structure. The objective of this work is to design and implement a framework for building multi-disciplinary finite element programs. Generality, reusability, extendibility, good performance and memory efficiency are considered to be the main points in design and implementation of this framework. Preparing the structure for team development is another objective because usually a team of experts in different fields are involved in the development of multi-disciplinary code. Kratos, the framework created in this work, provides several tools for easy implementation of finite element applications and also provides a common platform for natural interaction of its applications in different ways. This is done not only by a number of innovations but also by collecting and reusing several existing works. In this work an innovative variable base interface is designed and implemented which is used at different levels of abstraction and showed to be very clear and extendible. Another innovation is a very efficient and flexible data structure which can be used to store any type of data in a type-safe manner. An extendible IO is also created to overcome another bottleneck in dealing with multi-disciplinary problems. Collecting different concepts of existing works and adapting them to coupled problems is considered to be another innovation in this work. Examples are using an interpreter, different data organizations and variable number of dofs per node. The kernel and application approach is used to reduce the possible conflicts arising between developers of different fields and layers are designed to reflect the working space of different developers also considering their programming knowledge. Finally several technical details are applied in order to increase the performance and efficiency of Kratos which makes it practically usable. This work is completed by demonstrating the framework’s functionality in practice. First some classical single field applications like thermal, fluid and structural applications are implemented and used as benchmark to prove its performance. These applications are used to solve coupled problems in order to demonstrate the natural interaction facility provided by the framework. Finally some less classical coupled finite element algorithms are implemented to show its high flexibility and extendibility