Driven precast concrete geothermal energy piles: Current state of knowledge

Geothermal energy piles are increasingly luring attention in the construction industry as a cost-effective and environmental friendly solution for heating and cooling buildings. Energy piles are used as the primary unit in the ground source heat pump systems, which exchange heat with the ground. Energy piles are generally categorized into driven (displacement) and cast-in-place (non-displacement) piles. The present paper aims to review the available methods of design and construction of driven precast concrete energy pile foundations and provides a clear understanding of its construction challenges. Additionally, precast and cast-in-place energy pile foundations are compared. This paper found that precast concrete-driven energy pile foundations are a competitive alternative to cast-in-place energy piles. Driven concrete energy piles have higher quality control and quality assurance in the construction process; they have an easier, faster, and more reliable installation. Several other advantages and limitations related to the technical, economical, and environmental aspects of such piles are discussed in detail. The driven precast concrete foundations have a large worldwide market; however, there is a lack of guidelines, design standards, and experience for using such foundations as energy piles

What Characterizes the Productive Morphosyntax of Norwegian Children with Developmental Language Disorder?

Abstract Little is known about the productive morphosyntax of Norwegian children with developmental language disorder (DLD). The current study examined morphosyntax in Norwegian-speaking children with DLD ( n =19) and a control group that was pairwise matched for age, gender, and intelligence quotient (IQ; n = 19). The children’s sentence repetitions were studied through the lens of Processability Theory. The group differences were largest for grammatical structures at the latest developmental stage of the processability hierarchy. The Norwegian subordinate clause word order, belonging to the latest stage of the processability hierarchy, stood out as particularly challenging for children with DLD. Only 2 children with DLD but 16 children in the control group produced a subordinate clause with subordinate clause word order. Categorization of children’s errors revealed that children with DLD made more errors of all types (addition, omission, substitution, inflection and word order) but especially errors of omission and inflection

Brazilian undergraduate nursing students’ critical thinking need to be increased: a cross-sectional study

Objectives: to map Brazilian undergraduate nursing students’ critical thinking level and investigate the correlation between selected sociodemographic data and critical thinking domains. Methods: in this descriptive cross-sectional study, participants’ (N=89) critical thinking was assessed using the Health Science Reasoning Test. Correlation between critical thinking domains and sociodemographic data was assessed using the Pearson correlation coefficient. Results: the overall results showed a moderate level of participants’ critical thinking (mean = 70.7; standard deviation 5.7). A poor performance was identified in 5 of the 8 critical thinking domains. A significant positive correlation was found between education period and critical thinking (p<.001). Conclusions: poor level in students critical thinking domains may lead to negative consequences for their learning outcomes. Further studies should be carried out to confirm our results, in addition to investigation of teaching methods that encourage and ensure the development of students’ critical thinking skills during nursing education

Global Asymptotic Tracking for Marine Vehicles using Adaptive Hybrid Feedback

This paper presents an adaptive hybrid feedback control law for global asymptotic tracking of a hybrid reference system for marine vehicles in the presence of parametric modeling errors. The reference system is constructed from a parametrized loop and a speed assignment specifying the motion along the path, which decouples the geometry of the path from the motion along the path. During flows, the hybrid feedback consists of a proportional-derivative action and an adaptive feedforward term, while a hysteretic switching mechanism that is independent of the vehicle velocities determines jumps. The effectiveness of the proposed control law is demonstrated through experiments

The Nehari problem for the Paley--Wiener space of a disc

There is a bounded Hankel operator on the Paley–Wiener space of a disc in R2 which does not arise from a bounded symbol

Data-driven simultaneous identification of the 6DOF dynamic model and wave load for a ship in waves

In marine operations, the performance of model-based automatic control design and decision support systems highly relies on the accuracy of the representative mathematical models. Model fidelity can be crucial for safe voyages and offshore operations. This paper proposes a data-driven parametric model identification of a ship with 6 degrees of freedom (6DOF) exposed to waves using sparse regression according to the vessel motion measurements. The features of the complex ship dynamics are extracted and expressed as a linear combination of several functions. Thruster inputs and environmental loads are considered. The hydrodynamic coefficients and wave-induced loads are simultaneously estimated. Unlike earlier studies using a limited number of unknown functions, a library of abundant candidate functions is applied to fully consider the coupling effects among all DOFs. The benefit of the proposed method is that it does not require the exact construction of the library functions. Based on the estimated model, short-term motion prediction is achievable. The algorithm is verified through experiments. The method can be extended to other types of floating structures

Reconstruction of surface pressures on flat plates impacted by blast waves using the Virtual Fields Method

An accurate description of surface pressure loads imposed by blast waves is crucial for the design of the next generation of blast-resistant structures. However, experimental techniques for non-intrusive, full-field surface pressure measurements are not readily available. To address this challenge, a new application of the Virtual Fields Method (VFM) has been explored to reconstruct the surface pressures acting on thin steel plates using full-field deformation measurements of the plate dynamics. A shock tube facility was used to generate a blast-like loading in controlled, laboratory environments, where the plate dynamics were measured using the deflectometry technique. Different blockages at the shock tube exit allowed for varying the spatial distribution and temporal history of the blast loading. The surface pressures were reconstructed from experimentally measured kinematic fields using the VFM. A nearly non-deformable plate equipped with point-wise pressure sensors was also used to obtain a reference, allowing to assess the performance and reliability of the proposed methodology in capturing the surface pressure distributions. Moreover, visualizations of the different blast wave impacts on the plate were obtained using a background-oriented schlieren setup. Finally, the influence of potential error sources was investigated by means of a virtual laboratory using a finite element analysis to generate synthetic input to the load reconstruction analysis. The proposed methodology provided robust, precise predictions using noise-free input from virtual experiments. The presence of both systematic and random errors during the experimental campaign resulted in a reduced pressure reconstruction accuracy, where the peak pressure amplitudes were approximately 10–20% lower compared to the pointwise transducer data. Pressure reconstructions from experimental data still showed qualitatively good estimates of the pressure distributions that were extrapolated from transducer data. Hence, this work highlights the capabilities of a promising methodology to obtain more insight into the effective action of the loading during blast–structure interaction of plated structures. Previous article in issu

Vehicle assisted bridge damage assessment using probabilistic deep learning

Vehicle assisted monitoring has shown promising potential for the condition assessment of existing bridges in a road network, by removing practical complications faced in traditional Structural health monitoring (SHM) methods such as traffic interruption and dense deployment of sensors. However, the combination of different measurement sources during vehicle assisted monitoring has not yet been fully explored. This paper aims to evaluate the potential benefit of considering multiple measured responses from various sources, including fixed sensors on the bridge and on-board vehicle sensors. To this end, this paper proposes a Probabilistic Deep Neural Network, a stochastic data-driven framework for damage assessment. This framework enables the combination of vehicle and bridge responses to extract damage sensitive features for the classification of different damage states. In addition, the proposed method estimates the uncertainty of its predictions, providing an indication of the reliability of the result. The proposed method is validated using two numerical based case studies while considering realistic operational conditions, which include temperature oscillations, additional traffic, and measurement noise. The results from this study indicate that combining multiple sensor information results in lower uncertainties in damage detection and localisation. The results also suggest that the proposed method is robust in handling measurement noise and varying environmental conditions

Learn, Teach, Heal: Articulations of Indigeneity and Spirituality in Indigenous Tourism in British Columbia, Canada

‘Learn, Teach, Heal’ encapsulates what seems to be occurring in Indigenous Tourism on Vancouver Island and the Haida Gwaii in British Columbia, Canada. Operating as a ‘Tourist-researcher’ in 2017 and 2018, I was there at a time when Indigenous Tourism was booming, partly facilitated by the political movement of Truth & Reconciliation. Tourism is often seen as a shallow, commercial and artificial activity, yet such a view risks speaking over the various reasons why hosts choose to engage in the industry. This dissertation offers a case study based on tours, performances and interviews with six people. The research foregrounds the voices and experiences of: Andy Everson, Tana Thomas, Roy Henry Vickers, Tsimka Martin, K’odi Nelson and Alix Goetzinger. In listening to how they present their work, I study how indigeneity and spirituality were being articulated in ways that relate to processes of decolonisation. Whilst they were all engaged in tourism for their own different reasons, a common theme that emerged was the goal to use tourism to learn, teach and heal, both for themselves and for their guests. Learning how to be guides and performers, their languages, traditional practices, histories and politics, they were able to explore with tourists aspects of their indigeneity and spirituality, illustrate diversity of peoples and practices, and teach about their values and hopes for the future. Healing is gained through having a space to learn and to teach, and to restore pride to the communities by taking control of the narratives. It is my contention that Indigenous Tourism is offering these six people sites of ‘becoming’ and ‘reclaiming’ in a way that puts decolonisation into practice