Multibody modelling of a TB31 and a TB32 crash test with vertical portable concrete barriers: model verification and sensitivity analysis.

In this article the multibody simulation software package MADYMO for analysing and optimizing occupant safety design was used to model crash tests for Normal Containment barriers in accordance with EN 1317. The verification process was carried out by simulating a TB31 and a TB32 crash test performed on vertical portable concrete barriers and by comparing the numerical results to those obtained experimentally. The same modelling approach was applied to both tests to evaluate the predictive capacity of the modelling at two different impact speeds. A sensitivity analysis of the vehicle stiffness was also carried out. The capacity to predict all of the principal EN1317 criteria was assessed for the first time: the acceleration severity index, the theoretical head impact velocity, the barrier working width and the vehicle exit box. Results showed a maximum error of 6% for the acceleration severity index and 21% for theoretical head impact velocity for the numerical simulation in comparison to the recorded data. The exit box position was predicted with a maximum error of 4°. For the working width, a large percentage difference was observed for test TB31 due to the small absolute value of the barrier deflection but the results were well within the limit value from the standard for both tests. The sensitivity analysis showed the robustness of the modelling with respect to contact stiffness increase of ±20% and ±40%. This is the first multibody model of portable concrete barriers that can reproduce not only the acceleration severity index but all the test criteria of EN 1317 and is therefore a valuable tool for new product development and for injury biomechanics research.

Reconciling Children's Policy and Children's Rights: Barriers to Effective Government Delivery

Countries which have ratified the United Nations Convention on the Rights of the Child, have committed to implementing its principles in law and policy. This article explores the challenges for securing children's rights through policy, drawing on a research project conducted for the Northern Ireland Commissioner for Children and Young People, which sought to identify barriers to effective government delivery for children and young people from the perspective of key stakeholders. The research concluded that, while some barriers (such as delay and availability of data) are not child-specific, they can be accentuated when children and young people are the main focus of policy development and more so when seeking to adopt a child rights-compliant approach to policy development and implementation. 

The perspectives of ‘disengaged’ students in the 14–19 phase on motivations and barriers to learning within the contexts of institutions and classrooms

In addressing educational disengagement, government policy in England focuses primarily on raising the age of educational participation, promoting vocationalism and directing resources at the population of young people not engaged in any education, employment or training (NEETs). However, ‘disengagement’ is a more fluid and dynamic concept than policy allows for and is visible within a wide range of students, even those deemed to be engaged by their presence in education and educational settings. This paper presents students’ accounts of their educational experiences which suggest that the context of the classroom, student–teacher relationships, peer relationships and pedagogical methods used in classrooms are salient factors in understanding engagement.

The Reintegration of Sex Offenders: Barriers and Opportunities for Employment

The process of reintegration of offenders after release from prison, or during a community sentence, is a key aim of criminal justice policy. This article provides details from recent research that investigated the barriers and opportunities to employment for sex offenders. The authors describe the barriers that are faced by sex offenders and the anxieties that employers experience when employing sex offenders. The authors conclude that the approach taken by the State is less than reintegrative and serves to increase the barriers and reduce the opportunities for employment for sex offenders.

Gabions: evaluation of potential as low-cost roadside barriers

This paper evaluates the potential of gabions as roadside safety barriers. Gabions have the capacity to blend into natural landscape, suggesting that they could be used as a safety barrier for low-volume road in scenic environments. In fact, gabions have already been used for this purpose in Nepal, but the impact response was not evaluated. This paper reports on numerical and experimental investigations performed on a new gabion barrier prototype. To assess the potential use as a roadside barrier, the optimal gabion unit size and mass were investigated using multibody analysis and four sets of 1:4 scaled crash tests were carried out to study the local vehicle-barrier interaction. The barrier prototype was then finalised and subjected to a TB31 crash test according to the European EN1317 standard for N1 safety barriers. The test resulted in a failure due to the rollover of the vehicle and tearing of the gabion mesh yielding a large working width. It was found that although the system potentially has the necessary mass to contain a vehicle, the barrier front face does not have the necessary stiffness and strength to contain the gabion stone filling and hence redirect the vehicle. In the EN1317 test, the gabion barrier acted as a ramp for the impacting vehicle, causing rollover. 

The barriers & solutions to providing good quality palliative care in dementia in the GP practice

BACKGROUND: Dementia is a significant worldwide health issue, however, it is often insidious in onset and difficult to diagnose, therefore GPs have expressed a limited confidence in their diagnostic skills, extending into their prognostication of the disease. As a result diagnosing the terminal phase of dementia has been identified as a significant challenge to delivering effective palliative care. Therefore, identifying the challenges faced by the GPs in this field will help to guide their training and support, and as a result could assist in the provision of sustained and effective palliative care for their dementia patients.

Monte Carlo calculations of quantum yield in inhomogeneous PtSi/p-Si Schottky barriers

Monte Carlo calculations of quantum yield in PtSi/p-Si infrared detectors are carried out taking into account the presence of a spatially distributed barrier potential. In the 1-4 mu m wavelength range it is found that the spatial inhomogeneity of the barrier has no significant effect on the overall device photoresponse. However, above lambda = 4.0 mu m and particularly as the cut-off wavelength (lambda approximate to 5.5 mu m) is approached, these calculations reveal a difference between the homogeneous and inhomogeneous barrier photoresponse which becomes increasingly significant and exceeds 50% at lambda = 5.3 mu m. It is, in fact, the inhomogeneous barrier which displays an increased photoyield, a feature that is confirmed by approximate analytical calculations assuming a symmetric Gaussian spatial distribution of the barrier. Furthermore, the importance of the silicide layer thickness in optimizing device efficiency is underlined as a trade-off between maximizing light absorption in the silicide layer and optimizing the internal yield. The results presented here address important features which determine the photoyield of PtSi/Si Schottky diodes at energies below the Si absorption edge and just above the Schottky barrier height in particular.

Barriers to Goals of Care Discussions With Seriously Ill Hospitalized Patients and Their Families: A Multicenter Survey of Clinicians

Importance: Seriously ill hospitalized patients have identified communication and decision making about goals of care as high priorities for quality improvement in end-of-life care. Interventions to improve care are more likely to succeed if tailored to existing barriers.

Objective: To determine, from the perspective of hospital-based clinicians, (1) barriers impeding communication and decision making about goals of care with seriously ill hospitalized patients and their families and (2) their own willingness and the acceptability for other clinicians to engage in this process.

Design, Setting, and Participants: Multicenter survey of medical teaching units of nurses, internal medicine residents, and staff physicians from participating units at 13 university-based hospitals from 5 Canadian provinces.

Main Outcomes and Measures: Importance of 21 barriers to goals of care discussions rated on a 7-point scale (1 = extremely unimportant; 7 = extremely important).

Results: Between September 2012 and March 2013, questionnaires were returned by 1256 of 1617 eligible clinicians, for an overall response rate of 77.7% (512 of 646 nurses [79.3%], 484 of 634 residents [76.3%], 260 of 337 staff physicians [77.2%]). The following family member-related and patient-related factors were consistently identified by all 3 clinician groups as the most important barriers to goals of care discussions: family members' or patients' difficulty accepting a poor prognosis (mean [SD] score, 5.8 [1.2] and 5.6 [1.3], respectively), family members' or patients' difficulty understanding the limitations and complications of life-sustaining treatments (5.8 [1.2] for both groups), disagreement among family members about goals of care (5.8 [1.2]), and patients' incapacity to make goals of care decisions (5.6 [1.2]). Clinicians perceived their own skills and system factors as less important barriers. Participants viewed it as acceptable for all clinician groups to engage in goals of care discussions-including a role for advance practice nurses, nurses, and social workers to initiate goals of care discussions and be a decision coach.

Conclusions and Relevance: Hospital-based clinicians perceive family member-related and patient-related factors as the most important barriers to goals of care discussions. All health care professionals were viewed as playing important roles in addressing goals of care. These findings can inform the design of future interventions to improve communication and decision making about goals of care.

General practitioners’ perceptions of the barriers and solutions to good quality palliative care in dementia

The general practitioner (GP) is in a pivotal position to initiate and adapt care for their patients living with dementia. This study aimed to elicit GPs' perceptions of the potential barriers and solutions to the provision of good-quality palliative care in dementia in their practices. A postal survey of GPs across Northern Ireland was conducted with open-ended items soliciting for barriers in their practices and possible solutions; 40.6% (138/340) were returned completed. Barriers to palliative care in dementia were perceived to be a dementia knowledge deficit for healthcare staff and the public, a resource shortfall within the GP practice and community, poor team coordination alongside inappropriate dementia care provision, and disagreements from and within families. These findings have significant implications for educators and clinicians as enhanced dementia education and training were highlighted as a strong agenda for GPs with the suggestions of dementia awareness programmes for the public.