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Finite element simulation of damage and failure predictions of relatively thick carbon fibre-reinforced laminated composite panels subjected to flat and round noses low velocity drop-weight impact
No full textThis work is concerned with the dynamic computational modelling of fibre-reinforced laminated composite panels subjected to low velocity drop-weight impacts. Wings and fuselage of aircraft structures are prone to tool (box) drop impacts during normal shipping and handling of component assembly and maintenance services. Flat nose impacts inflict localised barely visible internal damage that severely reduce compressive residual strength and might result in catastrophic failure during future operations. Hence it is important to have a better understanding of the impact response of composites to mitigate the damage and avert the unexpected failures. Many reported works on the topic are experimental, based on quasi-static indentations that take longer than contact time, and produce global deformations of thin panel where short time effects and through-thickness stresses are neglected. Hence dynamic model is needed to investigate impact behaviour of thick panels for detailed information. The present computational model includes short time effects and utilise through-thickness stresses in mode-based failure criteria to differentiate ply-by-ply failure modes. Cases of laminates up to 7.6 mm thick impacted with flat and round (for comparisons) nose impactors were simulated using ABAQUS (TM)/Explicit dynamic routine. High stress concentration regions were meshed with adaptive meshing techniques using reduced integration elements. Selected simulation results were compared against experimental, intra-simulation results, and the data available in the literature and found to be in acceptable agreement. (C) 2016 Elsevier Ltd. All rights reserved
Salivary diagnostics using multi-OMICS technologies
No full textEarly diagnosis of diseases is crucial to prevent complications that could have a negative impact on a patient's quality of life. This research illustrates that a sampling of saliva provides an attractive medium for detecting a range of candidate disease biomarkers, such as proteins, electrolytes, hormones, antibodies and DNA/RNA, as well as other substances such as therapeutic or recreational drugs
Transient resistive switching devices made from egg albumen dielectrics and dissolvable electrodes
No full textEgg albumen as the dielectric, and dissolvable Mg and W as the top and bottom electrodes are used to fabricate water-soluble memristors. 4 × 4 cross-bar configuration memristor devices show a bipolar resistive switching behavior with a high to low resistance ratio in the range of 1 × 102 to 1 × 104, higher than most other biomaterial-based memristors, and a retention time over 104 s without any sign of deterioration, demonstrating its high stability and reliability. Metal filaments accompanied by hopping conduction are believed to be responsible for the switching behavior of the memory devices. The Mg and W electrodes, and albumen film all can be dissolved in water within 72 h, showing their transient characteristics. This work demonstrates a new way to fabricate biocompatible and dissolvable electronic devices by using cheap, abundant, and 100% natural materials for the forthcoming bioelectronics era as well as for environmental sensors when the Internet of things takes off
Perspectives on teachers’ numeracy, investigated via examination of comment and conversation.
No full textFor those training to teach in England, numeracy is required to fulfil the remit of a complete teacher education qualification. Trainee teachers in the post-compulsory sector must address their own level and depth of numerical comprehension whilst also examining the factors that surround the acquisition of this knowledge for their own learners in the classroom. For those training to teach in the compulsory sectors of primary or secondary education, a GCSE graded C or above and the completion of an additional numeracy professional skills test is required.Anecdotal evidence suggested prior to the initiation of research that numeracy within teacher education programs was not favourably received or welcomed by either trainee teachers or more established teachers. This research investigates in the first phase teachers’ and trainee teachers’ opinion and perception of numeracy using data collected from educational forums, prospectuses from teacher education providers, a critical review of resources available to support learning of numeracy for trainee teachers. In the second phase research utilises the observation of the delivery of a functional skills mathematics programme for teachers in the post-compulsory sector, recording information from participant observation, an online bulletin board and focus groups. Each successive method, through two distinct phases of research, focusses on comments and conversation, examining what teachers’ say to better understand their perceptions and opinions about the subject of numeracy.The findings indicate that teachers in the post-compulsory sector are reluctant to undertake any form of numeracy learning and those taking the training for the compulsory sector experience a lot of anxiety about the numeracy professional skills test in particular. The depth of negativity found to be present is extremely high with teachers’ words being collected and examined for their positive or negative direction and being overwhelming in their negative attitudes and opinions. Negative past experiences of teachers’ inform the development of negative perceptions of their own abilities and add to the anxiety they experience in relation to numeracy learning. Those teaching or training to teach are likely to be qualified to a university level but still demonstrate very high levels of negativity towards numeracy learning.The second research finding of conflict was present within the data not only from teachers’ words but also in the wording of prospectuses aimed at providing information for prospective trainees. The conflict was clear where prospectuses demonstrated avoidance of the mention of 3 numeracy as a course requirement for teaching, appearing to prefer not to stir up feelings of anxiety and negativity that are related to numeracy and mathematics. Teachers experienced conflicts between the need to maintain levels of professionalism, the traits expected of a teacher and their own feelings surrounding the subject. The findings of the research have been distilled down into the two main areas of negativity and conflict in relation to the perceptions and opinions of numeracy learning for teachers’.A naturalistic method has been used throughout to capture information that is not solicited and is not volunteered specifically for the purposes of research. The methods throughout analyse comments and conversation, however many of these take the form of online conversation or postings leading to a development in the innovative methodology which utilises the internet and electronic forms of communication.All of the research data is brought together for analysis to inform and support future practice in teachers’ numeracy through the development of a more positive attitude towards learning in numeracy for teachers. The development of a model for delivery is proposed which incorporates the findings and uses an acknowledgement of the inherent negativity surrounding the subject as a starting point for teachers’ numeracy learning to be more effective
The role of the pharmacist in the support of young people with chronic illness, through the exemplar of juvenile arthritis
No full textStandards to support learning and assessment in practice.
No full textThis is the first article in a series of 11 that will offer guidance to new and existing mentors and practice teachers to enable them to develop in their role and help them to gather a portfolio of evidence that meets the Nursing and Midwifery Council’s Standards to Support Learning and Assessment in Practice (SSLAP). This article provides background to the development of the standards and outlines the SSLAP, including the four main stages of the framework, the eight domains and outcomes, and the five principles required for the roles of mentor, sign-off mentor and practice teacher. The requirements for maintaining the mentor and practice teacher roles are explored
The lineages of play
No full textDoes each generation invent its own ways of playing, or is there a historical connectivity behind play that can be traced backwards through time? Building upon aesthetics of play on the one hand and genealogical lineages of player practices on the other, this paper sketches an argument for the continuity of play, and the connectivity between art, toys, and games, as well as between human and animal play.The paper is structured both by the aesthetic motives for play (a tentative inventory of motivations for pursuing play of any kind) and by a novel concept of logarithmic time, that simplifies historical reference into arbitrary but carefully structured intervals in order to describe the transitions and developments (whether putative or archaeological) in the player practices that constitute play. The result is a whistle-stop journey 'through time' in order to examine the lineages of play
A micro gas chromatography with separation capability enhanced by polydimethylsiloxane stationary phase functionalized by carbon nanotubes and graphene
No full textPolydimethylsiloxane (PDMS) stationary phases functionalized with multi-walled carbon nanotubes (MWCNTs) and graphene, respectively, for the columns in micro gas chromatography are presented in this paper. To exploit the merits of MWCNTs and graphene in terms of their high specific surface area, low surface energy and chemical inertness, experimental conditions for separation (heating rate and final temperature of temperature programming, flow rate of carrier gas and the volume of samples injection) are investigated, and separations of both polar and nonpolar compound mixtures under these conditions are performed. Compared with PDMS-only coated stationary phases, the functionalization of the phases with carbon nano-materials improves the performance of columns in separation, repeatability, stability and revolution significantly
Influence of silver loaded antibacterial agent on knitted and nonwoven fabrics and some fabric properties
No full textThe antibacterial effect of silver on knitted and nonwoven structures has been investigated. Three types of interlocked knitted fabrics (100% polyester, 100% viscose and 50%/50% polyester/viscose) were scoured and treated with silver ions by pad-dry-cure method. A nonwoven fabric (100% bleached cotton) was also treated with silver ions by using a spray technique. Physical and tensile properties of the treated fabrics were analyzed and compared with those of corresponding untreated ones. Results indicate that scouring process and antimicrobial treatment influenced the physical properties and antimicrobial effectiveness of the fabrics. An increase in tensile strength of 100% polyester and 100% viscose is observed after the antimicrobial treatment. The absorbency of all the treated knitted fabrics is decreased but it is substantially increased in the case of nonwoven fabrics. Antimicrobial activity of the treated fabrics was tested against Gram-positive bacterium Staphylococcus aureus. The results show that the treated nonwoven and blended (50%/50% polyester/viscose) knitted fabrics registered highest antimicrobial effect
