Interaction of wave with a body submerged below an ice sheet with multiple arbitrarily spaced cracks

The problem of wave interaction with a body submerged below an ice sheet with multiple arbitrarily spaced cracks is considered, based on the linearized velocity potential theory together with the boundary element method. The ice sheet is modeled as a thin elastic plate with uniform properties, and zero bending moment and shear force conditions are enforced at the cracks. The Green function satisfying all the boundary conditions including those at cracks, apart from that on the body surface, is derived and is expressed in an explicit integral form. The boundary integral equation for the velocity potential is constructed with an unknown source distribution over the body surface only. The wave/crack interaction problem without the body is first solved directly without the need for source. The convergence and comparison studies are undertaken to show the accuracy and reliability of the solution procedure. Detailed numerical results through the hydrodynamic coefficients and wave exciting forces are provided for a body submerged below double cracks and an array of cracks. Some unique features are observed, and their mechanisms are analyzed

Thermal stability of β-lactoglobulins A and B: Effect of SDS, urea, cysteine and N-ethylmaleimide

Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to monitor changes in the secondary structure and thermal stability of β-lactoglobulin A and B in the presence of sodium dodecyl sulphate (SDS), N-ethylmaleimide (NEM), urea and cysteine. An increase in the thermal stabilities of both proteins was noted in the presence of 10 mM-SDS. In the presence of 50 mM-SDS, there was extensive denaturation of both variants. In general, the β-strand/β-sheet regions in the secondary structure of both variants were very susceptible to denaturation by SDS and cysteine, suggesting that these regions may be held by hydrophobic and disulphide bonds. At ambient temperature and physiological pH, a notable difference was observed in the 1636 and 1627 cm -1 regions of the FTIR spectra of the two β-Ig variants. The results suggest possible differences in the nature of the β-sheet/β-strand distribution/content of the two proteins. Urea and NEM at a concentration of 50 mM, had little effect on the secondary structure and denaturation of both variants. New findings are presented which further indicate that although the β-Ig B variant showed greater thermal stability than the A variant in all the cases studied, its denaturation temperature and secondary structure were affected to a greater extent by the protein perturbants than ß-Ig A.published_or_final_versio

Wave radiation and diffraction by a circular cylinder submerged below an ice sheet with a crack

Wave radiation and diffraction by a circular cylinder submerged below an ice sheet with a crack are considered based on the linearized velocity potential theory together with multipole expansion. The solution starts from the potential due to a single source, or the Green function satisfying both the ice sheet condition and the crack condition, as well as all other conditions apart from that on the body surface. This is obtained in an integral form through Fourier transform, in contrast to what has been obtained previously in which the Green function is in the series form based on the method of matched eigenfunction expansion in each domain on both sides of the crack. The multipole expansion is then constructed through direct differentiation of the Green function with respect to the source position, rather than treating each multipole as a separate problem. The use of the Green function enables the problem of wave diffraction by the crack in the absence of the body to be solved directly. For the circular cylinder, wave radiation and diffraction problems are solved by applying the body surface boundary condition to the multipole expansion, through which the unknown coefficients are obtained. Extensive results are provided for the added mass and damping coefficient as well as the exciting force. When the cylinder is away from the crack, a wide spacing approximation method is used, which is found to provide accurate results apart from when the cylinder is quite close to the crack

Deep Impression: Audiovisual Deep Residual Networks for Multimodal Apparent Personality Trait Recognition

Here, we develop an audiovisual deep residual network for multimodal apparent personality trait recognition. The network is trained end-to-end for predicting the Big Five personality traits of people from their videos. That is, the network does not require any feature engineering or visual analysis such as face detection, face landmark alignment or facial expression recognition. Recently, the network won the third place in the ChaLearn First Impressions Challenge with a test accuracy of 0.9109

Influence of charge trapping on electroluminescence from Si-nanocrystal light emitting structure

We report a study on the influence of charge trapping on electroluminescence (EL) from Si nanocrystal (nc-Si) distributed throughout a 30 nm Si O2 thin film synthesized by Si+ implantation into an oxide film thermally grown on a p -type Si substrate. The electron and hole trapping in the nc-Si located near the indium tin oxide gate and the Si substrate, respectively, cause a reduction in the EL intensity. The reduced EL intensity can be recovered after the trapped charges are released. A partial recovery can be easily achieved by the application of a positive gate voltage or thermal annealing at hot temperatures (e.g., 120 °C) for a short duration. The present study highlights the impact of charging in the nc-Si on the light emission efficiency and its stability of nc-Si light-emitting devices. © 2007 American Institute of Physics.published_or_final_versio

Synthesis and electromagnetic wave absorption property of amorphous carbon nanotube networks on a 3D graphene aerogel/BaFe12O19 nanocomposite

Homogeneous amorphous carbon nanotube (ACNT) networks have been synthesized using floating catalyst chemical vapor deposition method on a 3D graphene aerogel (GA)/ BaFe12O19 (BF) nanocomposite which was prepared by a self-propagating combustion process. The as-synthesized ACNT/GA/BF nanocomposite with 3D network structures could be directly used as a good absorber material for electromagnetic wave absorption. The experimental results indicated that the minimum reflection loss of ACNT/GA/BF composite with a thickness of 2 mm was -18.35 dB at 10.64 GHz in the frequency range of 2-18 GHz. The frequency bandwidth of the reflection loss below -10 dB was 3.32 GHz and below -5 dB was 6.24 GHz, respectively. The 3D graphene aerogel structures which composed of dense interlined tubes and amorphous structure bearing quantities of dihedral angles could consume the incident waves through multiple reflection and scattering inside the 3D web structures. The interlinked ACNTs have both the virtues of amorphous CNTs (multiple reflection inside the wall) and crystalline CNTs (high conductivity), consuming the electromagnetic wave as resistance heat. ACNT/GA/BF composite has a good electromagnetic wave absorption performance.Institute of Textiles and Clothing2016-2017 > Academic research: refereed > Publication in refereed journalbcr

Managing women in pregnancy after bariatric surgery: The midwife as the co-ordinator of care

Bariatric surgery is a recommended, cost-effective, evidenced-based intervention to reduce weight and associated comorbidities in severely obese people. People with a BMI of 40 kg/m2 or more, or a BMI between 35–40 kg/m2 with other medical conditions such as diabetes, hypertension, high cholesterol and obstructive sleep apnoea meet the criteria to be considered for bariatric surgery. Over the past 10 years, bariatric surgery in the UK has been more widely accessible and consequently midwives may be required to care for pregnant women who have undergone bariatric surgery such as a gastric band, sleeve gastrectomy and gastric bypass. Midwives are required to work co-operatively, recognising and working within the limits of their competence and providing leadership. The aim of this article is to consider the midwife's role as co-ordinator of care for pregnant women who have undergone bariatric surgery. It outlines the most common bariatric procedures and specific considerations, including nutritional supplementation required when providing care to women in the antenatal and postnatal period