Naresuan University Journal
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Non-linear FE Modelling of CFRP-strengthened RC Slabs under Cyclic Loading
No full textThe nonlinear behaviour of an adhesive layer connecting carbon fibre reinforced polymer (CFRP) to reinforced concrete one way slabs is numerically simulated in the current study. This investigation is aimed at developing as well as validating a three-dimensional finite element model. Numerical results have been compared with those obtained from an earlier experimental study. The FE model was then subjected to the modified fatigue load protocol recommended by FEMA 461. A detailed and accurate 3D FE model of the composite one-way slab was developed using ABAQUS software. A non-linear damage plasticity model is considered for modelling the concrete, and the FE model accounted for the nonlinearity of the concrete under cyclic loading by estimating the stiffness degradation in the concrete for both compression and tension effects. A surface cohesive based model was used to describe the interaction between the CFRP and the concrete slab. For the reinforcement bars, the Bauschinger effect was adopted through the application of the kinematic hardening model under cyclic loading. The FE model was then validated by comparing numerical and experimental values for load-deflection, load-strain in CFRP and load-strain in embedded reinforcement bars. Furthermore, the strain profile of CFRP, slip at interface in monotonic and cyclic loading, and both reduction in the ultimate load and stiffness due to cyclic loading were observed in this study
Rasch analysis of a new Patient reported outcome measure for Psoriasis Treatment (PROMPT)
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Temporal Pattern Recognition for Gait Analysis Applications Using an “Intelligent Carpet” System
No full textWe report on the demonstration of a novel floorsensor system for gait analysis in the time domain. The ability ofthe system to detect changes in gait was evaluated using patternrecognition techniques. The selected machine learning modelssuccessfully classified 10 different walking manners performedon the floor sensor system. Their range was defined in termsof the amplitude, frequency and type of the temporal signal.Between three and five consecutive footsteps were captured pergait experiment. For the data analysis five machine learning timeseries features were engineered for assessment of 12 machinelearning models. The tested machine learning models includeslinear, non-linear and ensemble methods. The top F-score performanceobtained was 88% using a finely tuned Random Forestmodel. We conclude that pattern recognition in gait activitiesmonitored by the floor sensor system is suitable for gait analysisapplications, ranging from biometrics to healthcare
In Situ Synthesis of PbS Nanocrystals in Polymer Thin Films from Lead(II) Xanthate and Dithiocarbamate Complexes: Evidence for Size and Morphology Control
No full textLead sulfide has been grown from single molecular precursors within a polymer matrix to form networks of PbS nanocrystals. These materials are model systems for the processing of polymer–nanoparticle layers for flexible hybrid photovoltaic devices. Processing is achieved by spin coating a solution containing the precursor and polymer onto a substrate, followed by heating of the film to decompose the precursor. The effect of precursor chemistry has been explored using lead(II) dithiocarbamates, their 1,10-phen adducts, and lead(II) xanthates with different alkyl chain lengths (butyl, hexyl, and octyl). The xanthates were found to be more promising precursors giving control over nanocrystal size and shape on variation of the alkyl chain length. The lead(II) octyl xanthate complex causes anisotropic growth, forming PbS nanowires within the polymer matrix
Hidden caring, hidden carers? Exploring the experience of carers for people with long term conditions
No full textThe role of exercise in the management of rheumatoid arthritis.
No full textRheumatoid arthritis (RA) is a chronic inflammatory disease associated with significant functional impairment and increased risk for cardiovascular disease. Along with pharmacological therapy, exercise seems to be a very promising intervention to improve disease-related outcomes, including functional ability and systemic manifestations, such as the increased cardiovascular risk. In this review, we discuss the physiological mechanisms by which exercise improves inflammation, cardiovascular risk and psychological health in patients with rheumatoid arthritis (RA) and describe in detail how exercise can be incorporated in the management of this disease using real examples from our clinical practice
Choice of Starting Dose for Biopharmaceuticals in First-in-Human Phase I Cancer Clinical Trials.
No full textBACKGROUND: First-in-human (FIH) trials of low-molecular-weight anticancer agents conventionally derive a safe start dose (SD) from one-tenth the severely toxic dose in 10% of rodents or one-sixth the highest nonseverely toxic dose (HNSTD) in nonrodent species. No consensus has been reached on whether this paradigm can be safely applied to biotechnology-derived products (BDPs). MATERIALS AND METHODS: A comprehensive search was conducted to identify all BDPs (excluding immune checkpoint inhibitors and antibody drug conjugates) with sufficient nonclinical and clinical data to assess the safety of hypothetical use of one-sixth HNSTD in an advanced cancer FIH trial. RESULTS: The search identified 23 BDPs, of which 21 were monoclonal antibodies. The median ratio of the maximum tolerated or maximum administered dose (MTD or MAD) to the actual FIH SD was 36 (range, 8-500). Only 2 BDPs reached the MTD. Hypothetical use of one-sixth HNSTD (allometrically scaled to humans) would not have exceeded the MTD or MAD for all 23 BDPs and would have reduced the median ratio of the MTD or MAD to a SD to 6.1 (range, 3.5-55.3). Pharmacodynamic (PD) markers were included in some animal toxicology studies and were useful to confirm the hypothetical SD of one-sixth HNSTD. CONCLUSION: One-sixth HNSTD would not have resulted in unacceptable toxicities in the data available. Supporting its use could reduce the number of dose escalations needed to reach the recommended dose. A low incidence of toxicities in animals and humans underscores the need to identify the pharmacokinetic and PD parameters to guide SD selection of BDPs for FIH cancer trials. IMPLICATIONS FOR PRACTICE: Start dose (SD) for biotechnology-derived products (BDPs) can be safely derived from one-sixth the highest nonseverely toxic dose in nonrodent species and may reduce the number of dose escalations needed to reach the recommended dose in first-in-human studies while limiting unnecessary exposure to high drug levels in humans. The use of this type of SD could improve the design of phase I studies of BDPs by making them more efficient. The role of preclinical pharmacodynamic markers was useful in confirming the hypothetical SD, and attempts should be explored in future animal studies to identify such parameters
Automated quantitative measurements and associated error covariances for planetary image analysis
No full textThis paper presents a flexible approach for extracting measurements from planetary images based upon the newly developed linear Poisson models technique. The approach has the ability to learn surface textures then estimate the quantity of terrains exhibiting similar textures in new images. This approach is suitable for the estimation of dune field coverage or other repeating structures. Whilst other approaches exist, this method is unique for its incorporation of a comprehensive error theory, which includes contributions to uncertainty arising from training and subsequent use. The error theory is capable of producing measurement error covariances, which are essential for the scientific interpretation of measurements, i.e. for the plotting of error bars. In order to apply linear Poisson models, we demonstrate how terrains can be described using histograms created using a 'Poisson blob' image representation for capturing texture information. The validity of the method is corroborated using Monte Carlo simulations. The potential of the method is then demonstrated using terrain images created from bootstrap re-sampling of martian HiRISE data