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Drug Breakdown: Methylphenidate
Get PDFIn this column, Sharon Rees aims to refresh knowledge and interest in some of the commonly used drugs in a series of tweets. This month she is talking about #methylphenidat
Characterization of quenched MD simulated porous carbon electrodes for supercapacitors
Get PDFPore architecture in porous materials is an important characteristics to determine energy and power densities of energy storage and conversion devices. Characterization techniques, such as BET, BJH, DFT, etc. either overestimates the data or is computationally expensive. To the best of authors’ knowledge, no known existing techniques are present that can measure pore interconnectivity for exclusively microporous carbon. We utilised the power of MD simulation to provide pathway for experimentalists in developing techniques for measurement of pore interconnectivity. A systematic exploration of quenched molecular dynamics (QMD) simulations followed by a thorough characterization for understanding the pore architecture of electrode structures with varying pore sizes was performed. We have developed a new sphere pore modelling technique for the identification of pore interconnectivity based on throats that will allow ions to move in and out of the pores during charging and discharging respectively. New parameters, namely coordination coefficient and throat aspect ratio which quantifies networking and homogeneity of the pores and throats, respectively, were introduced. Decreasing the annealing temperatures, it was observed that the coordination coefficient increased by 18.5 % and throat aspect ratio decreased by 2%. The proposed method and outcomes of this study may help experimentalists in developing new characterization technique particular aimed at estimating pore connectivity
Contract Violations in the Construction Projects: How Contractual Obligations are Reached Affects Contractual and Reputational Enforcement
Get PDFContract violations are frequent in construction projects due to the higher level of uncertainty and complexity in these projects. However, enforcement after a violation, including contractual and reputational enforcement, has received limited attention. This study distinguishes between three types of violations, i.e., violations of documented obligations (letter violations), violations of tacitly agreed obligations (spirit violations #1), and violations of unilaterally assumed obligations (spirit violations #2), based on the documentation and mutuality dimensions. Furthermore, this study compares the impacts of different types of violations on contractual and reputational enforcement and explores the mediating role of relational risk perception in the above impacts. By using the data collected from Chinese general contractors, this study concludes that compared with spirit violations #2, letter violations and spirit violations #1 will lead to more severe contractual enforcement and reputational enforcement while the latter two have no significant differences of their influence on the severity of enforcement. The mediating effects of relational risk perception are empirically supported. By doing this, this study contributes to the literature on contractual governance by exploring the effects of contract structure, especially the undocumented elements of contracts, on enforcement, and responds to the recent calls for the positive role of contract ambiguity. In addition, this study fills the gaps in the scarce literature on reputational enforcement and expands the studies on the antecedents of it. Project managers can benefit from this study by recognizing the employment of reputational enforcement and the making better alignment between different types of violations and enforcement
Our future in space: The physical and virtual opening-up of parliaments to publics
Get PDFParliaments are physical symbols of nationhood and democracy. Public access to these spaces is often strictly regulated, yet it remains highly influential to public experiences of parliament (and their engagement with it). Drawing on data collected for the Inter-Parliamentary Union’s 2022 Global Parliamentary Report, this article discusses ways in which parliamentary ‘space’ can be utilised to encourage public engagement. This encompasses the effective use of physical space, virtual reality and augmented reality for the purpose of public engagement. In doing so, we show the most important and effective strategy for (re)using, and opening up, parliamentary spaces: the complementary use of physical and virtual methods in not only bringing publics to parliament, but also bringing parliament to publics
Ecological and Carbon Footprints of Cities
No full textPopulation and urbanisation are main contributors of carbon emissions, energy demand, resource consumption, waste generation and climate change. Tackling climate change is the emerging challenge of cities as through the process of obtaining their natural resource needs, they influence their ecological and carbon footprints. Ecological and carbon footprints have become critical indicators for navigating the progress towards reducing Greenhouse Gas (GHG) emissions and climate change. Thus, it is vital that the ecological and carbon footprints data capture the city supply chains comprehensively. In this article, we look at carbon and ecological footprints of cities at different levels and show how city input-output databases fulfill several necessities that allows comparisons of cities and help inform viable decision-making. We also consider input-output data of ecological and carbon footprints required to examine progress of cities towards reducing GHG emissions across whole supply chains to inform evidence-based policy making towards sustainability and climate change policies
End-to-end Lip-reading: A Preliminary Study
Get PDFDeep lip-reading is the combination of the domains of computer vision and natural language processing. It uses deep neural networks to extract speech from silent videos. Most works in lip-reading use a multi staged training approach due to the complex nature of the task. A single stage, end-to-end, unified training approach, which is an ideal of machine learning, is also the goal in lip-reading. However, pure end-to-end systems have not yet been able to perform as good as non-end-to-end systems. Some exceptions to this are the very recent Temporal Convolutional Network (TCN) based architectures. This work lays out preliminary study of deep lip-reading, with a special focus on various end-to-end approaches. The research aims to test whether a purely end-to-end approach is justifiable for a task as complex as deep lip-reading. To achieve this, the meaning of pure end-to-end is first defined and several lip-reading systems that follow the definition are analysed. The system that most closely matches the definition is then adapted for pure end-to-end experiments. Four main contributions have been made: i) An analysis of 9 different end-to-end deep lip-reading systems, ii) Creation and public release of a pipeline1 to adapt sentence level Lipreading Sentences in the Wild 3 (LRS3) dataset into word level, iii) Pure end-to-end training of a TCN based network and evaluation on LRS3 word-level dataset as a proof of concept, iv) a public online portal2 to analyse visemes and experiment live end-to-end lip-reading inference. The study is able to verify that pure end-to-end is a sensible approach and an achievable goal for deep machine lip-reading
Design and Characterization of a Low-Cost and Efficient Torsional Spring for ES-RSEA
Get PDFThe design of torsional springs for series elastic actuators (SEAs) is challenging, especially when balancing good stiffness characteristics and efficient torque robustness. This study focuses on the design of a lightweight, low-cost, and compact torsional spring for use in the energy storage-rotary series elastic actuator (ES-RSEA) of a lumbar support exoskeleton. The exoskeleton is used as an assistive device to prevent lower back injuries. The torsion spring was designed following design for manufacturability (DFM) principles, focusing on minimal space and weight. The design process involved determining the potential topology and optimizing the selected topology parameters through the finite element method (FEM) to reduce equivalent stress. The prototype was made using a waterjet cutting process with a low-cost material (AISI-4140-alloy) and tested using a custom-made test rig. The results showed that the torsion spring had a linear torque-displacement relationship with 99% linearity, and the deviation between FEM simulation and experimental measurements was less than 2%. The torsion spring has a maximum torque capacity of 45.7 Nm and a 440 Nm/rad stiffness. The proposed torsion spring is a promising option for lumbar support exoskeletons and similar applications requiring low stiffness, low weight-to-torque ratio, and cost-effectiveness
Analysis of changes in the national mental health nursing workforce in England, 2011-2021
Get PDFData regarding changes in characteristics of the MHN workforce is commonly cited in governmental publications, but is rarely analysed in peer reviewed journals, despite ongoing concerns regarding high vacancy rates within mental health services.
Aims To characterise changes in the MHN workforce, implementation of new nursing roles/skills and alignment with national policy
Method
Analysis of nationally published workforce data, peer reviewed publications and governmental policy/planning documents.
Results
Nurse numbers declined from 2011 to 2017, subsequently returning to near 2011 levels, but remaining below national targets. Nurses in community settings increased to constitute more than half of all nurses, whilst inpatient numbers declined, although more slowly than bed numbers. The ratio between nurses and support workers changed due to more support workers in inpatient settings. New advanced skills and roles for nurses have increased, but are unevenly distributed, constituting a small proportion of the total workforce.
Implications for practice
This paper provides a case study against which comparisons may be made with the nursing workforce in other countries and specialities. Even clear policy commitment to nursing growth may not deliver planned changes in numbers and introducing new roles may have uneven impact, especially in the absence of a robust evidence base
Nanoindentation Response of 3D Printed PEGDA Hydrogels in a Hydrated Environment
Get PDFHydrogels are commonly used materials in tissue engineering and organ-on-chip devices. This study investigated the nanomechanical properties of monolithic and multilayered poly(ethylene glycol) diacrylate (PEGDA) hydrogels manufactured using bulk polymerization and layer-by-layer projection lithography processes, respectively. An increase in the number of layers (or reduction in layer thickness) from 1 to 8 and further to 60 results in a reduction in the elastic modulus from 5.53 to 1.69 and further to 0.67 MPa, respectively. It was found that a decrease in the number of layers induces a lower creep index (CIT) in three-dimensional (3D) printed PEGDA hydrogels. This reduction is attributed to mesoscale imperfections that appear as pockets of voids at the interfaces of the multilayered hydrogels attributed to localized regions of unreacted prepolymers, resulting in variations in defect density in the samples examined. An increase in the degree of cross-linking introduced by a higher dosage of ultraviolet (UV) exposure leads to a higher elastic modulus. This implies that the elastic modulus and creep behavior of hydrogels are governed and influenced by the degree of cross-linking and defect density of the layers and interfaces. These findings can guide an optimal manufacturing pathway to obtain the desirable nanomechanical properties in 3D printed PEGDA hydrogels, critical for the performance of living cells and tissues, which can be engineered through control of the fabrication parameters