LASER INDUCED LAMB WAVE GENERATION FOR STRUCTURAL HEALTH MONITORING OF CARBON FIBER REINFORCED POLYMERS

ABSTRACT In this paper we present an innovative concept for the excitation of guided acoustic waves (lamb waves

Axial Globe Position Measurement: A Prospective Multicenter Study by the International Thyroid Eye Disease Society

Identify a reproducible measure of axial globe position (AGP) for multicenter studies on patients with thyroid eye disease (TED)

Towards reducing variations in infant mortality and morbidity : a population-based approach

Background: Our aims were (1) to improve understanding of regional variation in early-life mortality rates and the UK’s poor performance in international comparisons; and (2) to identify the extent to which late and moderately preterm (LMPT) birth contributes to early childhood mortality and morbidity. Objective: To undertake a programme of linked population-based research studies to work towards reducing variations in infant mortality and morbidity rates. Design: Two interlinked streams: (1) a detailed analysis of national and regional data sets and (2) establishment of cohorts of LMPT babies and term-born control babies. Setting: Cohorts were drawn from the geographically defined areas of Leicestershire and Nottinghamshire, and analyses were carried out at the University of Leicester. Data sources: For stream 1, national data were obtained from four sources: the Office for National Statistics, NHS Numbers for Babies, Centre for Maternal and Child Enquiries and East Midlands and South Yorkshire Congenital Anomalies Register. For stream 2, prospective data were collected for 1130 LMPT babies and 1255 term-born control babies. Main outcome measures: Detailed analysis of stillbirth and early childhood mortality rates with a particular focus on factors leading to biased or unfair comparison; review of clinical, health economic and developmental outcomes over the first 2 years of life for LMPT and term-born babies. Results: The deprivation gap in neonatal mortality has widened over time, despite government efforts to reduce it. Stillbirth rates are twice as high in the most deprived as in the least deprived decile. Approximately 70% of all infant deaths are the result of either preterm birth or a major congenital abnormality, and these are heavily influenced by mothers’ exposure to deprivation. Births at < 24 weeks’ gestation constitute only 1% of all births, but account for 20% of infant mortality. Classification of birth status for these babies varies widely across England. Risk of LMPT birth is greatest in the most deprived groups within society. Compared with term-born peers, LMPT babies are at an increased risk of neonatal morbidity, neonatal unit admission and poorer long-term health and developmental outcomes. Cognitive and socioemotional development problems confer the greatest long-term burden, with the risk being amplified by socioeconomic factors. During the first 24 months of life each child born LMPT generates approximately £3500 of additional health and societal costs. Conclusions: Health professionals should be cautious in reviewing unadjusted early-life mortality rates, particularly when these relate to individual trusts. When more sophisticated analysis is not possible, babies of < 24 weeks’ gestation should be excluded. Neonatal services should review the care they offer to babies born LMPT to ensure that it is appropriate to their needs. The risk of adverse outcome is low in LMPT children. However, the risk appears higher for some types of antenatal problems and when the mother is from a deprived background

Behavioural outcomes and psychopathology during adolescence

Preterm birth is associated with a high risk of residual neurodevelopmental disability and cognitive impairment. These problems are closely associated with psychiatric disorders and thus it is unsurprising that preterm birth also confers high risk for poor long term mental health. The risk associated with preterm birth is not a general one, but appears to be specific to symptoms and disorders associated with anxiety, inattention and social and communication problems, and manifest in a significantly higher prevalence of emotional disorders, ADHD and Autism. Adolescence is a key period for mental health and studies have shown that problems evident in childhood persist over this time and are more stable amongst preterm individuals than term-born peers. There is also modest evidence for an increased prevalence of psychotic symptoms in preterm adolescents. The high prevalence of psychiatric disorders, present in around 25% of preterm adolescents, requires long term screening and intervention

The Multiple Uses of Polypropylene/Polyethylene Terephthalate Microfibrillar Composite Structures to Support Waste Management—Composite Processing and Properties

Composite processing and subsequent characterization of microfibrillar composites (MFC) were the focus of this work. Compression molding of wound MFC filaments was used to fabricate MFC composites. The MFC composites were composed of polypropylene (PP) as matrix materials and polyethylene terephthalate (PET) as reinforcement fibers. The PP/PET blends were mixed with PET contents ranging from 22 wt% to 45 wt%. The effect of processing parameters, pressure, temperature, and holding time on the mechanical properties of the MFCs was investigated. Tensile tests were conducted to optimize the processing parameter and weight ratio of PET. Tensile strength and modulus increased with the increase in PET content. PP/45 wt% PET MFC composites properties reached the value of PP/30 wt% GF. Falling weight tests were conducted on MFC composites. The MFC composites showed the ability to absorb the impact energy compared to neat PP and PP/30 wt% GF

Effect of pollution on polychromed ceramic statues

Pigments of different colours used to polychrome ceramic statues have been characterized using different experimental techniques. The pigments detected in the painting layers belong to the group of natural minerals widely used in antique paintings. The polluted air and the composition of dust and crust on the ceramic surface have been analysed. Environmental pollution has altered the surface of the ceramic sculptures, destroying the polychrome, so that only small parts covered by crust or dust remain. The environment is responsible for transformation of the chemical components of the pigments. The lead compounds minium and hydrocerussite are altered to anglesite, cerussite, hydrocerussite and lead sulphide. Azurite, forming some blue colour, is hydrated to malachite which is green. Atacamite is formed by the transformation of azurite in the presence of the chloride ion from environmental pollution. The environment supplies a variety of organic compounds - mainly alkanes (produced by petrol combustion) - which are responsible for the black coating on the polychrome, which serves as nutrition for microbiological growth.This work was supported by Project SEC95-0793.Peer Reviewe

Electrochemical Surface Structuring for Strong SMA Wire–Polymer Interface Adhesion

Active hybrid composites represent a novel class of smart materials used to design morphing surfaces, opening up new applications in the aircraft and automotive industries. The bending of the active hybrid composite is induced by the contraction of electrically activated shape memory alloy (SMA) wires, which are placed with an offset to the neutral axis of the composite. Therefore, the adhesion strength between the SMA wire and the surrounding polymer matrix is crucial to the load transfer and the functionality of the composite. Thus, the interface adhesion strength is of great importance for the performance and the actuation potential of active hybrid composites. In this work, the surface of a commercially available one-way effect NiTi SMA wire with a diameter of 1 mm was structured by selective electrochemical etching that preferably starts at defect sites, leaving the most thermodynamically stable surfaces of the wire intact. The created etch pits lead to an increase in the surface area of the wire and a mechanical interlocking with the polymer, resulting in a combination of adhesive and cohesive failure modes after a pull-out test. Consequently, the force of the first failure determined by an optical stress measurement was increased by more than 3 times when compared to the as-delivered SMA wire. The actuation characterization test showed that approximately the same work capacity could be retrieved from structured SMA wires. Moreover, structured SMA wires exhibited the same shape of the stress–strain curve as the as-delivered SMA wire, and the mechanical performance was not influenced by the structuring process. The austenite start A$_s$ and austenite finish A$_f$ transformation temperatures were also not found to be affected by the structuring process. The formation of etching pits with different geometries and densities was discussed with regard to the kinetics of oxide formation and dissolution