860 research outputs found

    Optimisation of panel component regions subject to hot stamping constraints using a novel deep-learning-based platform

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    The latest hot stamping processes can enable efficient production of complex shaped panel components with high stiffness-to-weight ratios. However, structural redesign for these intricate processes can be challenging, because compared to cold forming, the non-isothermal and dynamic nature of these processes introduces complexity and unfamiliarity among industrial designers. In industrial practice, trial-and-error approaches are currently used to update non-feasible designs where complicated forming simulations are needed each time a design change is made. A superior approach to structural redesign for hot stamping processes is demonstrated in this paper which applies a novel deep-learning-based optimisation platform. The platform consists of the interaction between two neural networks: a generator that creates 3D panel component geometries and an evaluator that predicts their post-stamping thinning distributions. Guided by these distributions the geometry is iteratively updated by a gradient-based optimisation technique. In the application presented in this paper, panel component geometries are optimised to meet imposed constraints that are derived from post-stamping thinning distributions. In addition, a new methodology is applied to select arbitrary geometric regions that are to be fixed during the optimisation. Overall, it is demonstrated that the platform is capable of optimising selective regions of panel component subject to imposed post-stamped thinning distribution constraints

    Rapid feasibility assessment of components to be formed through hot stamping: A deep learning approach

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    The novel non-isothermal Hot Forming and cold die Quenching (HFQ) process can enable the cost-effective production of complex shaped, high strength aluminium alloy panel components. However, the unfamiliarity of designing for the new process prevents its widescale adoption in industrial settings. Recent research efforts focus on the development of advanced material models for finite element simulations, used to assess the feasibility of new component designs for the HFQ process. However, FE simulations take place late in design processes, require forming process expertise and are unsuitable for early-stage design explorations. To address these limitations, this study presents a novel application of a Convolutional Neural Network (CNN) based surrogate as a means of rapid manufacturing feasibility assessment for components to be formed using the HFQ process. A diverse dataset containing variations in component geometry, blank shapes, and processing parameters, together with corresponding physical fields is generated and used to train the model. The results show that near indistinguishable full field predictions are obtained in real time from the model when compared with HFQ simulations. This technique provides an invaluable tool to aid component design and decision making at the onset of a design process for complex-shaped components formed under HFQ conditions

    Electromagnetic form factor of pion from N_f=2+1 dynamical flavor QCD

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    We present a calculation of the electromagnetic form factor of the pion in Nf=2+1N_f=2+1 flavor lattice QCD. Calculations are made on the PACS-CS gauge field configurations generated using Iwasaki gauge action and Wilson-clover quark action on a 323×6432^3\times64 lattice volume with the lattice spacing estimated as a=0.0907(13)a=0.0907(13) fm at the physical point. Measurements of the form factor are made using the technique of partially twisted boundary condition to reach small momentum transfer as well as periodic boundary condition with integer momenta. Additional improvements including random wall source techniques and a judicious choice of momenta carried by the incoming and outgoing quarks are employed for error reduction. Analyzing the form factor data for the pion mass at Mπ≈411M_\pi \approx 411 MeV and 296 MeV, we find that the NNLO SU(2) chiral perturbation theory fit yields =0.441±0.046fm2=0.441 \pm 0.046 {\rm fm}^2 for the pion charge radius at the physical pion mass. Albeit the error is quite large, this is consistent with the experimental value of 0.452±0.011fm20.452\pm 0.011 {\rm fm}^2. Below Mπ≈300M_\pi\approx 300 MeV, we find that statistical fluctuations in the pion two- and three-point functions become too large to extract statistically meaningful averages on a 32332^3 spatial volume. We carry out a sample calculation on a 64464^4 lattice with the quark masses close to the physical point, which suggests that form factor calculations at the physical point become feasible by enlarging lattice sizes to MπL≈4M_\pi L\approx 4.Comment: 28 pages, 14 figure

    Improving engagement with healthcare in hepatitis C: a randomised controlled trial of a peer support intervention

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    National Institute for Health Research Policy Research Programme (‘Effectiveness of testing for treatment of hard-to-reach groups for latent tuberculosis, hepatitis B virus and hepatitis C virus in England: The HALT Study’, 015/0306

    Experience of specialist DVA provision under COVID-19: listening to service user voices to shape future practice

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    In the context of high rates of domestic violence and abuse (DVA) during the pandemic, specialist DVA services have been required to adapt rapidly to continue to deliver essential support to women and children in both refuges and the community. This study examines service users’ experiences and views of DVA service provision under COVID-19 and discusses implications for future practice. Data are drawn from a wider evaluation of DVA services in five sites in England. Fifty-seven semi-structured interviews and five focus groups were conducted with 70 female survivors and seven children accessing DVA services during the pandemic. Analysis identified key themes in respect of the influence of COVID-19 on the experience of service delivery. COVID-19 restrictions had both positive and negative implications for service users. Remote support reduced face-to-face contact with services, but consistent communication counteracted isolation. Digital practices offered effective means of providing individual and group support, but there were concerns that not all children were able to access online support. Digital support offered convenience and control for survivors but could lack privacy and opportunities for relationship-building. The pivot to remote delivery suggests directions where DVA services can expand the range and nature of future service provision

    Sex Pheromone Evolution Is Associated with Differential Regulation of the Same Desaturase Gene in Two Genera of Leafroller Moths

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    Chemical signals are prevalent in sexual communication systems. Mate recognition has been extensively studied within the Lepidoptera, where the production and recognition of species-specific sex pheromone signals are typically the defining character. While the specific blend of compounds that makes up the sex pheromones of many species has been characterized, the molecular mechanisms underpinning the evolution of pheromone-based mate recognition systems remain largely unknown. We have focused on two sets of sibling species within the leafroller moth genera Ctenopseustis and Planotortrix that have rapidly evolved the use of distinct sex pheromone blends. The compounds within these blends differ almost exclusively in the relative position of double bonds that are introduced by desaturase enzymes. Of the six desaturase orthologs isolated from all four species, functional analyses in yeast and gene expression in pheromone glands implicate three in pheromone biosynthesis, two Δ9-desaturases, and a Δ10-desaturase, while the remaining three desaturases include a Δ6-desaturase, a terminal desaturase, and a non-functional desaturase. Comparative quantitative real-time PCR reveals that the Δ10-desaturase is differentially expressed in the pheromone glands of the two sets of sibling species, consistent with differences in the pheromone blend in both species pairs. In the pheromone glands of species that utilize (Z)-8-tetradecenyl acetate as sex pheromone component (Ctenopseustis obliquana and Planotortrix octo), the expression levels of the Δ10-desaturase are significantly higher than in the pheromone glands of their respective sibling species (C. herana and P. excessana). Our results demonstrate that interspecific sex pheromone differences are associated with differential regulation of the same desaturase gene in two genera of moths. We suggest that differential gene regulation among members of a multigene family may be an important mechanism of molecular innovation in sex pheromone evolution and speciation

    A giant adrenal pseudocyst presenting with right hypochondralgia and fever: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Adrenal pseudocysts are rare cystic masses that arise from the adrenal gland and which are usually non-functional and asymptomatic. Adrenal pseudocysts consist of a fibrous wall without an epithelial or endothelial lining. We report the case of a patient with a giant adrenal pseudocyst presenting with right hypochondralgia and high fever.</p> <p>Case presentation</p> <p>A 52-year-old Japanese man was admitted with right hypochondralgia and a chill. Abdominal computed tomography revealed a well-defined cystic mass measuring 19 cm which was located in the right adrenal region and the contents of which were not enhanced with contrast medium. Abdominal ultrasonography revealed a heterogeneously hypo-echoic lesion with a peripheral high-echoic rim. Serum hormonal levels were almost normal. Despite treatment with antibiotics, the high fever persisted. Based on these findings, we made a preoperative diagnosis of a right adrenal cyst with infection. However, the possibility of malignancy still remained. The patient underwent laparotomy and right adrenal cyst excision with partial hepatectomy in order to relieve the symptoms and to confirm an accurate diagnosis. Histological examination revealed an adrenal pseudocyst with infection. His condition improved soon after the operation.</p> <p>Conclusion</p> <p>We report a case of a giant adrenal pseudocyst with infection. Surgery is required for symptomatic cases in order to relieve the symptoms and in cases of uncertain diagnosis.</p
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