Practical Element Research Articles

COVID-19 and anatomy: Stimulus and initial response.

The outbreak of COVID-19, resulting from widespread transmission of the SARS-CoV-2 virus, represents one of the foremost current challenges to societies across the globe, with few areas of life remaining untouched. Here, we detail the immediate impact that COVID-19 has had on the teaching and practice of anatomy, providing specific examples of the varied responses from several UK, Irish and German universities and medical schools. Alongside significant issues for, and suspension of, body donation programmes, the widespread closure of university campuses has led to challenges in delivering anatomy education via online methods, a particular problem for a practical, experience-based subject such as anatomy. We discuss the short-term consequences of COVID-19 for body donation programmes and anatomical education, and highlight issues and challenges that will need to be addressed in the medium to long term in order to restore anatomy education and practice throughout the world.

Caving-induced fault reactivation behaviour and its effects on mining safety with a multiple seam context

Caving-induced fault reactivation and its effects on caving process are widely recognized as serious safety issues in mining and tunnelling industry. In this study, the effects of a variety of factors (i.e. friction coefficient, stick–slip instability, geological structure, pre-mining status, mining and its induced effects) that might exert an influence on fault dynamic behaviour of a 5-seam coal mine are investigated using practical mine-wide finite element numerical models with a normal fault. Based on the research outcomes on R-minimum-based finite element modelling of earthquake dynamics, the node-to-point contact strategy and the nonlinear friction contact law have been used here to simulate and analyse the caving-induced stick–slip frictional instability along the fault and related effects. The simulation results show that: (1) stress distribution before mining is relatively uniform around the fault for a homogenous rock material case, while stress concentration appears around the fault for the model with contrasting rock material properties; (2) the multiple-layered models are in favour of fault reactivation than models with only one material for whole strata; (3) the fault reactivation scale (i.e. dynamic relative motion and fault slip) induced by caving activity is significantly affected by rock mass strength, caving depth and its relative position to the fault. As caving progresses deeper and closer to the fault, the fault reactivation scale increases. Meanwhile, the fault in low strength strata is much more sensitive to fault slip behaviour; (4) seismic source parameters, namely seismic moment and moment magnitude, are adopted to evaluate the magnitude of caving-induced seismicity based on numerical results and fault slip risk and magnitude increase as fault reactivation scale expands; (5) during the caving stage, the failure zone initiates, develops and eventually connects the reactivated fault to the working area, presenting asymmetric failure pattern around the caving zone. The failure zone is obviously larger for the side closer to the fault than the other side due to caving-induced fault reactivation effects. This could help in better understanding fault reactivation and rock failure behaviours towards an optimised design of caving in a faulted region.

102 Process Evaluation Exploring the Delivery and Uptake of Posture and Mobility Training for Staff in Care Homes

Abstract Introduction Provision of care for care home residents with complex needs is challenging. Physiotherapists can play a major role in enhancing the confidence, skills and abilities of care home staff. The Skilful Care Training Package (SCTP) aims to provide staff with an understanding of good posture and training in skilled facilitation of movement. This process evaluation explored barriers and facilitators to delivery and uptake of the SCTP within the context of a feasibility cluster randomised controlled trial (cRCT) in 10 care homes. Methods A mixed methods process evaluation, incorporating non-participant observations and interviews, conducted in the five care homes receiving the SCTP intervention. Interviews were audio recorded and transcribed verbatim; resident conversations were captured via a Dictaphone and/or field-notes. Data analysis used the Framework approach. Results Fourteen staff training sessions were observed. Interviews with 22 staff and four trainers, and 13 conversations with residents were completed. Five factors influenced delivery and uptake of the SCTP:Organisational factors: strategies to publicise and facilitate access to training improved attendance; a convenient training location and trainer flexibility encouraged attendance and staff engagement.Intervention delivery: a practical participatory element to the training was highly valued; adapting the training to meet the needs of the homes was well-received.Engagement and interaction: relating training to workplace and residents’ experiences engaged staff; high levels of engagement and positive interaction within the training sessions were reported; challenges relating to staff hierarchy affected training delivery in some homes.Intervention content: posture and mobility elements were seen as important; however, some repetition with prior training was highlighted.Training impact: there were indications that staff adopted SCTP techniques. Staff reported an increase in their wellbeing and confidence in movement facilitation; cascade training was reported in some homes. Conclusions Training was well-received, and feedback on its impact was largely positive. Practical elements were viewed favourably over classroom-based learning. Intervention content should be revised to optimise focus and avoid overlap with other training.

Virtual design and construction

Virtual Design and Construction (VDC) is the use of integrated multi-disciplinary performance models of design-construction projects to support explicit and public business objectives. Professor Levitt’s Virtual Design Team (VDT) project provided a fundamental point of departure of this work: the organisation model provides a central theoretical and practical element in the VDC framework. VDC models are virtual because they are computer-based descriptions of the project. This paper summarises the VDC framework that integrates an organisation perspective with perspectives that are implicit in VDT, including 3D Building Information Model (BIM) product models of a product to be designed, built and operated – typically a physical facility – management by objectives, Lean production management and the social method of Integrated Concurrent Engineering (ICE). Thus, VDC project models emphasise those aspects of the project that can be designed and managed, i.e., the product (typically a building or plant facility), the organisation that will define, design, construct and operate it, and the process that the organisation teams will follow. Many companies and hundreds of professionals now use VDC methods, and they consistently find that they improve project and business performance.

Pengembangan Panduan Teknik Mendongeng Untuk Meningkatkan Disiplin Diri Anak RA/PAUD/TK

The purpose of this study is to produce a storytelling guide to improve the self-discipline of RA / PAUD / TK students who have fulfilled the theoretical and practical aspects of acceptance. The development of storytelling guidelines to improve the self- discipline of RA / PAUD / TK students is an adaptation of the Borg & Gall (1983) research and development model, which was modified into three stages: 1) phase I: assessment and literature study, 2) phase II product development: formulating competency goals and standards, compiling indicators, compiling initial drafts, 3) phase III (testing): product validation (guidance and counseling expert, instructional media development expert, & user), and effectiveness testing in limited fields. Data collection instruments used were: product assessment questionnaire and self-discipline checklist. Quantitative data were analyzed by non-parametric statistics, while input / criticism / suggestions from experts were analyzed by qualitative descriptive analysis. The results of the assessment of theorists and user experts, of the storytelling guide to improve the self-discipline of RA / PAUD / TK students, have fulfilled the theoretical and practical acceptability element. The results of field trials show that this practical and effective storytelling guide is used to improve self-discipline.

Learning Aids of Risk Assessment Apps For Practical Engineering Student: A Case Study

In today's learning approaches for engineering students, practical courses frequently complement traditional theoretical lectures. This practical element allows an early perspective into the real world of engineering, augments student motivation, and enables students to acquire soft skills early. This paper aims to demonstrate the usage of one of the ergonomics risk assessment (ERA) apps that has been learned in the class; which can also be used as an assessment aid in student’s practical sessions in the workplace. This apps has been evaluated for its effectiveness by a group of students in the classroom setting prior to be used in the actual workplace. Evaluation results show that this learning aid improves student’s communication skills and assists companies to improve their working conditions. Based on the effectiveness assessment, students find that this apps is really useful for their assessment as it provides fast calculation on the results and can store it in the drive. Based on the practical session in the workplace, the findings from the ERA apps show that the current working condition in this study is under medium ergonomic risk exposure level. Therefore, there is a need to improve the working condition by considering improvement on the workplace environment as well as interaction between worker and tools for maintenance. This app is indeed beneficial for practical engineering students as a peer learning process and for industry in terms of work place improvements. In conclusion, this paper describes how this risk assessment app helps induce student to think as an actual engineer and also to solve real-world tasks with limited resources.

Simple Contact Stiffness Model Validation for Tie Bolt Rotor Design With Butt Joints and Pilot Fits

Abstract Tie bolt rotors for centrifugal compressors comprise multiple shaft components that are held together by a single tie bolt. The axial connections of these rotors—including butt joints, Hirth couplings, and Curvic couplings—exhibit a contact stiffness effect, which tends to lower the shaft bending frequencies compared to geometrically identical monolithic shafts. If not accounted for in the design stage, shaft bending critical speed margins can be compromised after a rotor is built. A previous paper had investigated the effect of tie bolt force on the bending stiffness of stacked rotor assemblies with butt joint interfaces, both with and without pilot fits. This previous work derived an empirical contact stiffness model and developed a practical finite element modeling approach for simulating the axial contact surfaces, which was validated by predicting natural frequencies for several test rotor configurations. The present work built on these previous results by implementing the same contact stiffness modeling approach on a real tie bolt rotor system designed for a high pressure centrifugal compressor application. Each joint location included two axial contact faces, with contact pressures up to five times higher than previously modeled, and a locating pilot fit. The free-free natural frequencies for different amounts of tie bolt preload force were measured, and the frequencies exhibited the expected stiffening behavior with increasing preload. However, a discontinuity in the data trend indicated a step-change increase in the contact stiffness. It was shown that this was likely due to one or more of the contact faces becoming fully engaged only after sufficient tie bolt force was applied. Finally, a design calculation was presented that can be used to estimate whether contact stiffness effects may be ignored, which could simplify rotor analyses if adequate contact pressure is used.

Choosing to study music: student attitudes towards the subject of music in second-level education in the Republic of Ireland

AbstractThe present study aimed to identify student (16–18 years) attitudes towards the subject of music in second-level education in the Republic of Ireland. The study, framed by an interpretivist approach, employed qualitative data collection methods through interviews and focus groups. Findings indicate that student attitudes to music were influenced by the following factors: their innate interest in the subject, which was strengthened by an existing musical skill or talent, and the perceived use of the subject as a pathway for entry to further/higher education or for a student’s professional career. The findings also suggested that the music curriculum and the teaching style of the music teacher impacted student attitudes as did the appeal of the practical element of the subject, particularly with regard to the practical assessment component. Some interpretations of these findings are explored.

Practical microstructure-informed dual-scale simulation for predicting hole expansion failure of hyper-burring steel

A practical dual-scale finite element model is developed to enable the formability prediction in the hole expansion of a hyper-burring steel sheet. This numerical approach resorts to the isotropic macroscale hole expansion simulation for calculating the deformation histories near the hole edge, since they are known to be the potential fracture initiation site. The deformation histories are used as boundary conditions in the lower microscale model for calculating the local fracture of the steel sheet. The microscale simulation utilizes the dislocation density based constitutive model and a microstructure-based representative volume element (RVE), with realistic grain morphology taken from experimental microscopy. The fracture initiation at the hole edge region is evaluated from the microscale simulation using four frequently employed uncoupled ductile fracture models, which enable the definition of the critical fracture strain. The proposed dual-scale model can better predict the failure initiation and location near the hole edge when the modeling parameters are calibrated taking into account not only the deformation histories of the hole edge, but also the local stress triaxiality. Moreover, the proposed dual-scale model is applied to analyze the microstructure effect on the hole expansion ratio by providing the insights into the effect of grain size and grain boundary characteristics.

A Numerical Study on Installation Effects and Long-Term Shaft Resistance of Pre-Bored Piles in Cohesive Soils

Pre-boring is a technique widely used to facilitate large displacement pile driving in hard/dense soils, but usually at the expense of reducing the long-term shaft resistance of the pile. In the US, it is a routine practice for large displacement pile to be driven through dense cohesive soils with the ultimate capacity of pre-bored piles usually being determined based on empiricism and local experience. Understanding and quantifying the impacts of pre-boring installation on pile capacity can greatly help geotechnical design engineers to understand the interactions among the factors of pre-boring, pile size, soil conditions, and so forth and to improve the design and construction qualities of pile foundations in hard/dense soils. Due to the high cost and time involved with field instrumentation and testing on pre-bored piles, a numerical analysis study was funded by the Louisiana Department of Transportation and Development (DOTD) as a first step to exploring the impacts of pre-bore size on the long-term shaft resistance reduction of piles. This study was conducted using a practical finite element model that integrates the entire process from pile installation through subsequent consolidation to pile loading. The long-term shaft resistance was then examined after full consolidation by applying a vertical shear displacement on the soil element adjacent to the pile until the ultimate state was reached. Based on the numerical simulations, a set of reduction factor curves were then developed for a typical Louisiana soil stratum, which may provide guidelines for better design and construction of pre-bored piles in Louisiana.

System of fractional differential algebraic equations with applications

Abstract One of the important classes of coupled systems of algebraic, differential and fractional differential equations (CSADFDEs) is fractional differential algebraic equations (FDAEs). The main difference of such systems with other class of CSADFDEs is that their singularity remains constant in an interval. However, complete classifying and analyzing of these systems relay mainly to the concept of the index which we introduce in this paper. For a system of linear differential algebraic equations (DAEs) with constant coefficients, we observe that the solvability depends on the regularity of the corresponding pencils. However, we show that in general, similar properties of DAEs do not hold for FDAEs. In this paper, we introduce some practical applications of systems of FDAEs in physics such as a simple pendulum in a Newtonian fluid and electrical circuit containing a new practical element namely fractors. We obtain the index of introduced systems and discuss the solvability of these systems. We numerically solve the FDAEs of a pendulum in a fluid with three different fractional derivatives (Liouville–Caputo’s definition, Caputo–Fabrizio’s definition and with a definition with Mittag–Leffler kernel) and compare the effect of different fractional derivatives in this modeling. Finally, we solved some existing examples in research and showed the effectiveness and efficiency of the proposed numerical method.

A Practical Wheel-Rail Interaction Element for Modeling Vehicle-Track-Bridge Systems

A novel practical element is presented for simulating the vertical wheel-rail interaction (WRI) of vehicle-track-bridge (VTB) coupling systems. The WRI is time- and location-varying, which makes the simulation of the VTB system complicated. The new element simulates the WRI using a location dependent internal resisting force, which enables the finite element (FE) model of the VTB system to remain unchanged in analysis. This element is capable of simulating the nonlinear WRI, the rail irregularity and the ‘additional’ displacement of the rail. The ‘additional’ displacement is the extra displacement caused by the WRI besides that interpolated from the element nodal displacements, which is usually ignored by existing models, but may be non-negligible in some cases. The WRI element is implemented into a general FE software framework, OpenSees, and verified by the dynamic analysis of a simply-supported beam subjected to a moving sprung mass. Furthermore, a realistic VTB system with a moving four-wheel vehicle is investigated to evaluate the cases where the additional displacement and nonlinear WRI should be considered. Finally, using another realistic VTB system subjected to rail irregularities and earthquakes, the effects of rail irregularity and earthquake on the dynamic responses of the WRI system are studied and compared.

إعداد ودعم المعلمین من أجل مواجهة التحدیات القائمة فی عملیة التعلم خلال القرن الحادی والعشرین فی منطقة آسیا والمحیط الهادئ الکفایات الممتدة (المستعرضة) فی سیاسات وممارسات التعلیم

مستخلص التقرير باللغة العربية : هدف هذا التقرير إلى تعرف قدرة المعلمين في بلدان منطقة آسيا والمحيط الهادئ على دمج الکفايات المستعرضة في المناهج الدراسية التقليدية، وتعرف قدرتهم على تقديم هذه الکفايات باعتبارها موضوعات قائمة بذاتها في الصف الدراسي و/أو أنشطة خارج المنهج الدراسي. طبق التقرير بتوزيع استبانات على أکثر من 400 مدرسة و2621 من المشارکين، 95 % منهم مدرسون، في منطقة آسيا والمحيط الهادئ، وکشفت النتائج أن غالبية المعلمين يثقون في قدراتهم على دعم تعلم الکفايات المستعرضة، في حين مثل ضعف الثقة مشکلة بالنسبة لبعضهم، وتراوحت نسبتهم من 3% في منغوليا إلى 18% في جمهورية کوريا، وکشفت المقابلات التي أجريت مع المعلمين أن سبب ضعف الثقة في کثير من الأحيان أعباء الطلبات المتنافسة التي تشغل وقتهم. وقد حدد المعلمون أن عنصر التدريب العملي الأکثر فائدة لهم في تيسير تعلم الکفايات المستعرضة؛ کما وأعربوا عن استيائهم من عدم الحصول على مبادئ توجيهية تفصيلية وأمثلة على الممارسات الجيدة لمساعدتهم على تعلمها، وعدم وجود إطار تقييم محدد لقياس مدى تطور الکفايات المستعرضة لديهم. وأکد المعلمون على الدور المهم لقادة المدارس في «إعادة توازن» البيئة المدرسية؛ بحيث تتحول من بيئة تقليدية ترکز على الامتحان إلى بيئة أکثر شمولا لتعليم وتعلم الکفايات المستعرضة. کما حدد المعلمون اهتمامات الطلاب ودعم أولياء الأمور باعتبارهما اثنين من أکثر العوامل تأثيرا على تمکين تعليم الکفايات المستعرضة في المدارس على نحو فعال، وعلى مستوى الأنظمة، تبذل بعض السلطات التعليمية جهودا کبيرة للانتقال من الترکيز على تحسين کمية التدريب المقدم أثناء الخدمة إلى تحسين نوعيته، وعن التزام استراتيجي واضح من عدة سلطات تعليمية لوضع رؤية تقدمية للتعليم، تشمل الکفايات المستعرضة. وخرجت الدراسة بالعديد من التوصيات. Report Abstract in English The aim of the Report is to identify the capacity of teachers in the Asia-Pacific region to integrate cross-functional skills into traditional curricula, and their ability to provide these competencies as stand-alone topics in the classroom and / or extracurricular activities. The survey found that the majority of teachers trust their ability to support the learning of transversal competencies, while the lack of confidence is a problem for some, and their percentage ranged from 3% in Mongolia to 18% in the Republic of Korea, and interviews with teachers revealed that the reason for poor trust is often the burdens of competing demands that occupy their time. Teachers identified that the most useful practical element in facilitating the learning of competencies reviewed was dissatisfaction with the lack of detailed guidelines and examples of good practices to help them learn, and the absence of a specific evaluation framework to measure the development of their transversal competencies. Teachers emphasized the important role of school leaders in rebalancing the school environment, transforming it from a traditional environment focused on the exam. To a more comprehensive environment for the teaching and learning of transversal competencies. Teachers also identified student interests and parental support as two of the most influential factors in effectively enabling learning of transversal competencies in schools. At the system level, some educational authorities are making significant efforts to shift from focusing on improving the amount of in-service training to improving quality, A clear strategic commitment from several educational authorities to establish a progressive vision of education, including transversal competencies. The study made several recommendations.

In Social Network Analysis, Which Centrality Index Should I Use? Theoretical Differences and Empirical Similarities among Top Centralities

This research examines four frequently used centrality indices — degree, closeness, betweenness, and eigenvectors — to understand the extent to which their clear theoretical distinctions are reflected in differences in empirical performance. Even for stylized networks in which one centrality index may seem more relevant than the others, the four indices are frequently highly correlated. This result can be interpreted as good news: it does not diminish the conceptual distinctions, yet it suggests the indices are rather robust, yielding similar information about actors’ positions in networks, which can be reassuring given their widespread use by applied network analysts who may not appreciate the theoretically distinct origins and definitions. This research also compares computational speed across the centrality indices as another practical element that may help determine the choice of centrality index.

An iterative method for exact eigenvalues and eigenvectors of general nonviscously damped structural systems

A novel and computationally efficient iterative method is proposed for the exact eigenvalues and eigenvectors of nonviscously damped vibration systems. General nonviscous damping model is assumed in which damping forces depend on the past motion history via convolution integrals over exponentially decaying kernel functions. The presence of nonviscous damping leads to complex frequency dependent eigenvalue problem whose solution requires either extensively augmented state-space formulation or iterative full complex eigensolutions on mode by mode basis, both of which are computationally expensive when practical systems with large dimensions are considered. By simply solving the eigenvalue problem of the underlying undamped vibration system, the real eigenvalues and eigenvectors can then be combined with the nonviscous damping matrix to develop an iterative procedure from which required complex eigenvalues and eigenvectors of the damped system can be computed. First order perturbation is employed to further improve the starting estimates of the desired eigenvalues and eigenvectors and the convergence is generally very fast. The proposed method is mathematically developed based on progressive eigensensitivity analysis and convergence is ensured when the norm of the damping matrix is of second order when compared with that of the stiffness matrix. Representative numerical examples of discrete mass spring damping model as well as practical finite element model with nonviscous damping are given to demonstrate and validate the accuracy and efficiency of the proposed iterative method.

Practical boundary element method for piled rafts

In this paper, a practical boundary element method (BEM) is developed to analyze piled rafts. The raft is modeled using the direct boundary element formulation for thick plates; which is suitable for such type of problems. An innovative methodology to add stiffness matrices to the plate integral equations is developed. Hence, pile–soil–raft interactions are added as a special case of the developed methodology. In order to avoid generating huge systems of coupled equations, an effective condensation technique of piles and soil degrees of freedom (DOFs) at pile–soil–raft interface is employed. Several numerical examples are presented and results are compared to previously published results. Then, a practical application is solved to demonstrate the strength and versatility of the proposed formulation.

A practical boundary element analysis of slab-beam floor type

This paper presents the analysis of slab-beam type floors using the boundary element method. The shear-deformable plate bending theory according to Reissner is used to model the slab, whereas the Bernnoli–Euller beam model (without losing the generality) is used to model beams. The developed formulation embeds the system of grid beams stiffness matrix into the plate bending integral equation. In other words, it can be regarded as coupling between the slab boundary elements and the beam finite elements. The resulting integral equations are solved by collocation at boundary elements and internal supporting beam nodes. The present formulation allows considering the beam real intersecting area with the slab along the beam's span. The corresponding numerical model is implemented into computer code. Applications to simple examples and real building slabs are solved then results are compared to those obtained from analytical solution, finite element method, and literature to ensure the validity of the developed formulation.

In Social Network Analysis, Which Centrality Index Should I Use?: Theoretical Differences and Empirical Similarities among Top Centralities

This research examines four frequently used centrality indices—degree, closeness, betweenness, and eigenvectors—to understand the extent to which their clear theoretical distinctions are reflected in differences in empirical performance. Even for stylized networks in which one centrality index may seem more relevant than the others, the four indices are frequently highly correlated. This result can be interpreted as good news: it does not diminish the conceptual distinctions, yet it suggests the indices are rather robust, yielding similar information about actors’ positions in networks, which can be reassuring given their widespread use by applied network analysts who may not appreciate the theoretically distinct origins and definitions. This research also compares computational speed across the centrality indices as another practical element that may help determine the choice of centrality index.

In-plane torsional stiffness in a macro-panel element for practical finite element modelling

Finite element (FE) analysis produces results, which, in most cases, gain in accuracy, as the size of the FE mesh is reduced. However, this is not necessarily the case when beam and shell element connections induce in-plane torsional effects in the shell. In such situations, shell elements either do not allow for an in-plane torsional stiffness, or, when present, the in-plane torsional stiffness is incorrectly affected by the sizes of the elements. To overcome this problem, we propose a macro- panel element that has fewer degrees of freedom, includes a new model for in-plane torsional stiffness, and produces results with sufficient accuracy to meet engineering requirements. The panel element is based on the principle of sub-structuring, i.e., the panel is meshed internally by smaller shell elements. As shown in the paper, the proposed panel element can be quite large, yet, it can give accurate analysis results. This work helps to overcome a common dilemma in practical use of finite element analysis, where finite element theory requires element sizes to be sufficiently small, but practical considerations suggest the use of large-size elements that simplify the modelling process and reduce excesses in generated results. A model built using macro-panel elements is equivalent to the model built using smaller shell elements, with the normal and shear stresses in the former being the same as the stresses in the finely meshed shell element model, We identify a number of performance benefits that become available as a consequence of modelling the shell elements at a higher level of abstraction.

Feature Extraction Method for Condition Monitoring of Rolling Element Bearings Based on Dual-Tree Complex Wavelet Packet Transform and VMD

The feature extraction of rolling element bearings vibration signals is one of the key issue for high-speed rotating machinery condition monitoring. A new scheme based on Dual-Tree Complex Wavelet Packet Transform (DTCWPT) and Variational Mode Decomposition (VMD) for extracting vibration condition monitoring feature is proposed. First, DTCWPT is used to reduce noise and pseudo frequency components from vibration signals by the energy ratio. Second, a set of Intrinsic Mode Function components (IMFs) can be got by VMD. Then, the energy ratio between the screening vibration signal and IMFs are calculated. And, the corresponding IMFs are selected according to the energy ratio threshold. Finally, applying the spectrum analysis technology, the condition monitoring feature can be extracted from the reconstructing signal. The experimental results of simulation signals and practical rolling element bearings vibration signals show that the scheme is feasible and effective for extracting the bearings operation state feature.