Extension of the virtual fields method to elasto-plastic material identification with cyclic loads and kinematic hardening

International audienceThe virtual fields method (VFM) has been specifically developed for solving inverse problems from dense full-field data. This paper explores recent improvements regarding the identification of elasto-plastic models. The procedure has been extended to cyclic loads and combined kinematic/isotropic hardening. A specific attention has also been given to the effect of noise in the data. Indeed, noise in experimental data may significantly affect the robustness of the VFM for solving such inverse problems. The concept of optimized virtual fields that minimize the noise effects, previously developed for linear elasticity, is extended to plasticity in this study. Numerical examples with models combining isotropic and kinematic hardening have been considered for the validation. Different load paths (tension, compression, notched specimen) have shown that this new procedure is robust when applied to elasto-plastic material identification. Finally, the procedure is validated on experimental data

Liver Involvement Associated with Dengue Infection in Adults in Vietnam

Globally, the number of adults hospitalized with dengue has increased markedly in recent years. It has been suggested that hepatic dysfunction is more significant in this group than among children. We describe the spectrum and evolution of disease manifestations among 644 adults with dengue who were prospectively recruited on admission to a major infectious disease hospital in southern Vietnam and compare them with a group of patients with similar illnesses not caused by dengue. Transaminase levels increased in virtually all dengue patients and correlated with other markers of disease severity. However, peak enzyme values usually occurred later than other complications. Clinically severe liver involvement was infrequent and idiosyncratic, but usually resulted in severe bleeding. Chronic co-infection with hepatitis B was associated with modestly but significantly increased levels of alanine aminotransferase, but did not otherwise impact the clinical picture

Facile Template In-Situ Fabrication of ZnCo2O4 Nanoparticles with Highly Photocatalytic Activities under Visible-Light Irradiation

High specific surface area ZnCo2O4 nanoparticles were prepared via a sacrificial template accelerated hydrolysis by using nanoparticles of ZnO with highly polar properties as a template. The obtained ZnCo2O4 nanoparticles were characterized by the method of scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurements, Transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The obtained nanoparticles were performed as a photocatalyst for the degradation of methylene blue in aqueous solution under visible irradiation. The photocatalytic degradation rate of methylene blue onto the synthesized ZnCo2O4 was higher than that of commercial ZnO and synthesized ZnO template. Copyright © 2019 BCREC Group. All rights reserved

Neutron Yield from (γ, n) and (γ, 2n) Reactions following 100 MeV Bremsstrahlung in a Tungsten Target

The photonuclear reactions of (γ, xn) or (γ, xnp) types can be used to produce high-intensity neutron sources for research and applied purposes. In this work a Monte-Carlo calculation has been used to evaluate the production yield of neutrons from the (γ, n) and (γ, 2n) reactions following the bremsstrahlung produced by a 100 MeV electron beam on a tungsten target

Clinical implications of reduced susceptibility to fluoroquinolones in paediatric Shigella sonnei and Shigella flexneri infections.

OBJECTIVES: We aimed to quantify the impact of fluoroquinolone resistance on the clinical outcome of paediatric shigellosis patients treated with fluoroquinolones in southern Vietnam. Such information is important to inform therapeutic management for infections caused by this increasingly drug-resistant pathogen, responsible for high morbidity and mortality in young children globally. METHODS: Clinical information and bacterial isolates were derived from a randomized controlled trial comparing gatifloxacin with ciprofloxacin for the treatment of paediatric shigellosis. Time-kill experiments were performed to evaluate the impact of MIC on the in vitro growth of Shigella and Cox regression modelling was used to compare clinical outcome between treatments and Shigella species. RESULTS: Shigella flexneri patients treated with gatifloxacin had significantly worse outcomes than those treated with ciprofloxacin. However, the MICs of fluoroquinolones were not significantly associated with poorer outcome. The presence of S83L and A87T mutations in the gyrA gene significantly increased MICs of fluoroquinolones. Finally, elevated MICs and the presence of the qnrS gene allowed Shigella to replicate efficiently in vitro in high concentrations of ciprofloxacin. CONCLUSIONS: We found that below the CLSI breakpoint, there was no association between MIC and clinical outcome in paediatric shigellosis infections. However, S. flexneri patients had worse clinical outcomes when treated with gatifloxacin in this study regardless of MIC. Additionally, Shigella harbouring the qnrS gene are able to replicate efficiently in high concentrations of ciprofloxacin and we hypothesize that such strains possess a competitive advantage against fluoroquinolone-susceptible strains due to enhanced shedding and transmission

Towards Smart Homes Using Low Level Sensory Data

Ubiquitous Life Care (u-Life care) is receiving attention because it provides high quality and low cost care services. To provide spontaneous and robust healthcare services, knowledge of a patient’s real-time daily life activities is required. Context information with real-time daily life activities can help to provide better services and to improve healthcare delivery. The performance and accuracy of existing life care systems is not reliable, even with a limited number of services. This paper presents a Human Activity Recognition Engine (HARE) that monitors human health as well as activities using heterogeneous sensor technology and processes these activities intelligently on a Cloud platform for providing improved care at low cost. We focus on activity recognition using video-based, wearable sensor-based, and location-based activity recognition engines and then use intelligent processing to analyze the context of the activities performed. The experimental results of all the components showed good accuracy against existing techniques. The system is deployed on Cloud for Alzheimer’s disease patients (as a case study) with four activity recognition engines to identify low level activity from the raw data captured by sensors. These are then manipulated using ontology to infer higher level activities and make decisions about a patient’s activity using patient profile information and customized rules

Preliminary study on phytogeography of Dipterocarpaceae Blume family in Vietnam

Biogeographically mapping flora of Vietnam requires the studies on the distribution of some important species groups for identifying the typical species composition of each phytochorion. The Dipterocarpaceae family contains taxa originated in tropical Asia and its subfamily of Dipterocarpoideae is proved to have Southeast Asia origin. In Vietnam, this family includes 43 species in 7 genera. In this study, Dipterocarpaceae species from 645 sites in Vietnam are assessed and compared to those in over the world. In Vietnam, this family distributes in tropical and/or slightly passing to subtropical climate but none of its species is naturally found in the Red River and the Mekong River deltas. In the world, the Dipterocarpaceae species found in Vietnam concentrated distributes in Indochina floristic region, corresponding to the originative area of South Myanmar. Statistically, there are 12 endemic species for the Indochinese floristic region and five of them are endemic for four provinces of this region related to Vietnam, respectively as follows: South China - 1, North Indochina - 1, South Indochina - 2 and Annam - 1. Additionally, some species distribute in East Asia floristic region of Holarctic Kingdom because of expanding the distribution area from the Indochinese floristic region. All genera of this family in Vietnam were originated in the Indochinese floristic region. Moreover, the floristic data and phytogeographical phylogeny diagram, based on analyses of phytogeography and DNA, would be better to use for finding out the distributional source or the forming time of species or genus, then the phylogenetic diagram.ReferencesAngiosperm Phylogeny Group, 2009. An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III. Botanical Journal of the Linnean Society, 161(2), 105-121. Ashton P.S., 1982. Dipterocarpaceae. In: Van Steenis C.G.G.J., 1979-1983, Flora Malesiana. Dipterocarpaceae. Martinus Nijhoff Publisher, The Hague, London, 9(2), 250p. Averyanov L.V., Phan K.L., Nguyen T.H., Harder D.K., 2003. Phytogeographic review of Vietnam and adjacent areas of Eastern Indochina, Komarovia, Saint Petersburg, 3, 1-83. Kress W.J., DeFilipps R.A., Farr E. and Yin D.Y.K., 2003. A checklist of the trees, shrubs, herbs and climbers of Myanmar. National Museum of Nature History, Washington DC, 45, 1-590. Le Tran Chan (Editor), 1999. Some characteristics of the flora of Vietnam. Science and Technique publishing house, Hanoi, 305p (Vietnamese). Li X.W., Li J., Ashton P.S., 2007. Dipterocarpaceae. In: Wu Z.Y., Raven P.H. (Hrsg.). Flora of China. Missouri Botanical Garden Press, St. Louis, 13, 48-54. Nguyen Hoang Nghia, 2005. Dipterocarps of Vietnam. Agriculture Publishing House, Hanoi, 100p. Nguyen Kim Dao, 2003. “Dipterocarpceae Blume, 1825” in Checklist Plant species of Vietnam. Agricultural Publishing House, Hanoi, 2, 328-340 (Vietnamese). Nguyen Nga Phi, 2009. Molecular phylogeny of Southeast-Asian Dipterocarps belonging to tribe Dipterocarpeae (family Dipterocarpaceae) based on non-coding sequence data of chloroplast and nuclear DNA. Department of Forest Genetics and Georest Tree Breeding, Büsgen Institute, Faculty of Forest Science and Forest Ecology, Georg-August University of Göttingen. Göttingen, 142p. Nguyen Nghia Thin, 2004. Methods in Botanical Research. HNU publishing house, Hanoi, 172p (Vietnamese). Pham Hoang Ho, 2001. Illustration Flora of Vietnam, Youth Publishing House. Ho Chi Minh City, 2, 1022p (Vietnamese). Smitinand T., 1969. The distribution of Dipterocarpaceae in Thailand. National History Bull. Siam Soci., 23, 67-75. Smitinand T., J.E. Vidal, P.H. Ho, 1990. Flore du Cambodge, du Laos et du Vietnam, 25, Diptérocarpacées. Muséum National d’Histoire Naturelle, Paris, 123p (French). Takhtajan A. (Translated by Theodore J. Crovello), 1986. Floristic Regions of the World. University of California Press, 544p. Thai Van Trung, 1978. Tropical Forest Ecology systems of Vietnam. Science and Technique publishing house, Hanoi, 314p (Vietnamese). The Plant List (Version 1.1.), 2013. Dipterocarpaceae. http://www.theplantlist.org

The Study of Isomeric Ratios in Photonuclear Reactions Forming High Spin Isomers in the Giant Dipole Resonance Region

We studied the isomeric ratios  in  odd-odd nuclei $^{196}$Au,$^{182}$Ta  and $^{194}$Ir  with    high spin isomeric states  produced  in $^{197}$Au$(\gamma,  n)$ $^{196m,g}$Au, $^{183}$W$(\gamma,  p)$ $^{182m,g}$Ta  and $^{185}$Pt$(\gamma,  p)$$^{194m,g}$Ir  reactions  by  using  the activation  technique  and  $\gamma$-ray  spectroscopic  method  in  the  giant    dipole  resonance  (GDR)  region.  The high-purity natural Au, W and Pt  foils in disc shape were irradiated with bremsstrahlungs  generated from an  electron  accelerator  Microtron.  The  irradiated  foils  were  measured  by  the  high  resolution  $\gamma$-ray spectroscopic system which consists of a Ge(HP) detector and a multichannel analyzer. In order to improve the  accuracy  of  the  experimental  results,  necessary  corrections  were  made  in  the  $\gamma$-ray  activity measurements and data analysis.  The results were  analyzed,  discussed and compared with those of other authors  as well as with theoretical model calculations.  The study shows that the isomeric ratios in  nuclei with high spin isomeric states are much lower than that in low spin isomeric state isomers