Simulation of Richtmyer-Meshkov Flows for Elastic-Plastic Solids in Planar and Converging Geometries Using an Eulerian Framework

This thesis presents a numerical and analytical study of two problems of interest involving shock waves propagating through elastic-plastic media: the motion of converging (imploding) shocks and the Richtmyer-Meshkov (RM) instability. Since the stress conditions encountered in these cases normally produce large deformations in the materials, an Eulerian description, in which the spatial coordinates are fixed, is employed. This formulation enables a direct comparison of similarities and differences between the present study of phenomena driven by shock-loading in elastic-plastic solids, and in fluids, where they have been studied extensively. In the first application, Whitham's shock dynamics (WSD) theory is employed for obtaining an approximate description of the motion of an elastic-plastic material processed by a cylindrically/spherically converging shock. Comparison with numerical simulations of the full set of equations of motion reveal that WSD is an accurate tool for characterizing the evolution of converging shocks at all stages. The study of the Richtmyer-Meshkov flow (i.e., interaction between the interface separating two materials of different density and a shock wave incoming at an angle) in solids is performed by means of analytical models for purely elastic solids and numerical simulations when plasticity is included in the material model. To this effect, an updated version of a previously developed multi-material, level-set-based, Eulerian framework for solid mechanics is employed. The revised code includes the use of a multi-material HLLD Riemann problem for imposing material boundary conditions, and a new formulation of the equations of motion that makes use of the stretch tensor while avoiding the degeneracy of the stress tensor under rotation. Results reveal that the interface separating two elastic solids always behaves in a stable oscillatory or decaying oscillatory manner due to the existence of shear waves, which are able to transport the initial vorticity away from the interface. In the case of elastic-plastic materials, the interface behaves at first in an unstable manner similar to a fluid. Ejecta formation is appreciated under certain initial conditions while in other conditions, after an initial period of growth, the interface displays a quasi-stationary long-term behavior due to stress relaxation. The effect of secondary shock-interface interactions (re-shocks) in converging geometries is also studied. A turbulent mixing zone, similar to what is observed in gas--gas interfaces, is created, especially when materials with low strength driven by moderate to strong shocks are considered

Bound and ground states of coupled “NLS-KdV” equations with Hardy potential and critical power

Universidad de Granada / CBU

Click to learn, learn to click: undergraduate synthetic organic chemistry experiments

The optimization of an undergraduate experiment for Organic Chemistry students is described to explore the concept of click chemistry. The preparation of a terminal fluorescent alkyne and an organic azide is reported consisting of simple steps. These are employed in the Cu(I)-catalized azide-alkyne cycloaddition to obtain a novel molecule containing a triazole ring whose characterization allows the students to practice a variety of techniques: NMR (1H, 13C, COSY and HSQC), melting point, thin layer chromatography, IR, fluorescence spectroscopy and mass spectrometry to confirm the structure of their obtained product. An alternative methodology in a one-pot reaction is also explored and a full laboratory manual provided.FQM-208. GlycoChemBio: Glycochemistry and Bioconjugatio

Present status and perspective on the future use of aflatoxin biocontrol products

Aflatoxin contamination of important food and feed crops occurs frequently in warm tropical and subtropical regions. The contamination is caused mainly by Aspergillus flavus and A. parasiticus. Aflatoxin contamination negatively affects health and trade sectors and causes economic losses to agricultural industries. Many pre- and post-harvest technologies can limit aflatoxin contamination but may not always reduce aflatoxin concentrations below tolerance thresholds. However, the use of atoxigenic (non-toxin producing) isolates of A. flavus to competitively displace aflatoxin producers is a practical strategy that effectively limits aflatoxin contamination in crops from field to plate. Biocontrol products formulated with atoxigenic isolates as active ingredients have been registered for use in the US, several African nations, and one such product is in final stages of registration in Italy. Many other nations are seeking to develop biocontrol products to protect their crops. In this review article we present an overview of the biocontrol technology, explain the basis to select atoxigenic isolates as active ingredients, describe how formulations are developed and tested, and describe how a biocontrol product is used commercially. Future perspectives on formulations of aflatoxin biocontrol products, along with other important topics related to the aflatoxin biocontrol technology are also discussed.Fil: Moral, Juan. Universidad de Córdoba; EspañaFil: Garcia-Lopez, Maria Teresa. Universidad de Córdoba; EspañaFil: Camiletti, Boris Xavier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Recursos Naturales. Cátedra de Microbiología Agrícola; ArgentinaFil: Jaime, Ramon. University of California at Davis; Estados UnidosFil: Michailides, Themis J.. University of California at Davis; Estados UnidosFil: Bandyopadhyay, Ranajit. International Institute of Tropical Agriculture; NigeriaFil: Ortega-Beltran, Alejandro. International Institute of Tropical Agriculture; Nigeri

Therapeutic alternatives in the management of osteoradionecrosis of the jaws. Systematic review

to systematically review the literature, comparing the healing of osteoradionecrosis (ORN) among the therapeutic alternatives: surgical, pharmacological and combined. The review was organized according to the PRISMA protocol with regards to the following PICO question: patients with ORN of the jaws (P=Patient); all interventions reported (I = intervention); between all therapies (C=Comparison); healing of lesions (O=outcome). Surgical treatment was the most common choice (46.3%) followed by pharmacological treatment, exclusively (25.9%) or combined (26.9%). Treatment exclusively by surgical intervention seems to be most effective option, with 51.2% of the lesions healed, OR for healing of 5.7 (CI95% 1.9-16.9, p=0.002). Only 1 case (0.9%) corresponded to low level laser therapy. It seems clear that early intervention with conservative surgical combined with pharmacological methods improves the prognosis of ORN

Intratumor genetic heterogeneity and clonal evolution to decode endometrial cancer progression

Endometrial cancer; Clonal evolution; MutationCáncer endometrial; Evolución clonal; MutaciónCàncer d'endometri; Evolució clonal; MutacióAnalyzing different tumor regions by next generation sequencing allows the assessment of intratumor genetic heterogeneity (ITGH), a phenomenon that has been studied widely in some tumor types but has been less well explored in endometrial carcinoma (EC). In this study, we sought to characterize the spatial and temporal heterogeneity of 9 different ECs using whole-exome sequencing, and by performing targeted sequencing validation of the 42 primary tumor regions and 30 metastatic samples analyzed. In addition, copy number alterations of serous carcinomas were assessed by comparative genomic hybridization arrays. From the somatic mutations, identified by whole-exome sequencing, 532 were validated by targeted sequencing. Based on these data, the phylogenetic tree reconstructed for each case allowed us to establish the tumors’ evolution and correlate this to tumor progression, prognosis, and the presence of recurrent disease. Moreover, we studied the genetic landscape of an ambiguous EC and the molecular profile obtained was used to guide the selection of a potential personalized therapy for this patient, which was subsequently validated by preclinical testing in patient-derived xenograft models. Overall, our study reveals the impact of analyzing different tumor regions to decipher the ITGH in ECs, which could help make the best treatment decision.We thank all those at the Translational Research Laboratory of the MD Anderson Cancer Center Madrid for their invaluable help with this study. Tissue samples were obtained with the support of the MD Anderson Foundation Biobank (record number B.0000745, ISCIII National Biobank Record), the “Xarxa Catalana de Bancs de Tumors” and “Plataforma de Biobancos” ISCIII (PT13/0010/0014, B.000609). This study has been supported by the Spanish Ministry of Economy and Innovation (PID2019-104644RB-I00 (GMB), the Instituto de Salud Carlos III (ISCIII, CIBERONC, CB16/12/00295 - GMB-, CB16/12/00328 -EC, AGM- and CB16/12/00231 -XMG- [all partly supported by FEDER funds]) and by the AECC Scientific Foundation (FC_AECC PROYE19036MOR -GMB- and Coordinated groups 2018 -XMG, AGM, GMB-). SO is funded by an AECC-postdoctoral grant (2020). JSR-F and BW are funded in part by the Breast Cancer Research Foundation and in part by the NIH/NCI P50 CA247749 01 grant. Research reported in this publication was supported in part by a Cancer Center Support Grant of the NIH/NCI (Grant No. P30CA008748; MSK). We thank the Eurofins Megalab laboratory for helping us to perform the analysis of DNA HPV detection

Prediction of the level of astringency in persimmon using visible and near-infrared spectroscopy

[EN] Early control of fruit quality requires reliable and rapid determination techniques. Therefore, the food industry has a growing interest in non-destructive methods such as spectroscopy. The aim of this study was to evaluate the feasibility of visible and near-infrared (NIR) spectroscopy, in combination with multivariate analysis techniques, to predict the level and changes of astringency in intact and in the flesh of half cut persimmon fruits. The fruits were harvested and exposed to different treatments with 95 % CO2 at 20 ºC for 0, 6, 12, 18 and 24 h to obtain samples with different levels of astringency. A set of 98 fruits was used to develop the predictive models based on their spectral data and another external set of 42 fruit samples was used to validate the models. The models were created using the partial least squares regression (PLSR), support vector machine (SVM) and least squares support vector machine (LS-SVM). In general, the models with the best performance were those which included standard normal variate (SNV) in the pre-processing. The best model was the PLSR developed with SNV along with the first derivative (1-Der) pre-processing, created using the data obtained at six measurement points of the intact fruits and all wavelengths (R2=0.904 and RPD=3.26). Later, a successive projection algorithm (SPA) was applied to select the most effective wavelengths (EWs). Using the six points of measurement of the intact fruit and SNV together with the direct orthogonal signal correction (DOSC) pre-processing in the NIR spectra, 41 EWs were selected, achieving an R2 of 0.915 and an RPD of 3.46 for the PLSR model. These results suggest that this technology has potential for use as a feasible and cost-effective method for the non-destructive determination of astringency in persimmon fruits.This work has been partially funded by the Institute Nacional de Investigacion y Tecnologia Agraria y Alimentaria de Espana (INIA) through research projects RTA2012-00062-004-01/03, RTA2013-00043-C02, and RTA2015-00078-00-00 with the support of European FEDER funds, and by the Conselleria d' Educacio, Investigacio, Cultura i Esport, Generalitat Valenciana, through the project AICO/2015/122. V. Cortes thanks the Spanish MEC for the FPU grant (FPU13/04202).Cortés López, V.; Rodríguez Ortega, A.; Blasco Ivars, J.; Rey Solaz, B.; Besada, C.; Cubero García, S.; Salvador, A.... (2017). Prediction of the level of astringency in persimmon using visible and near-infrared spectroscopy. JOURNAL OF FOOD ENGINEERING. 204:27-37. doi:10.1016/j.jfoodeng.2017.02.017S273720

Extended Life Qualification of the Magnetically Shielded Miniature (MaSMi) Hall Thruster

We present an update on the life qualification of the Magnetically Shielded Miniature (MaSMi) Hall thruster (also known as the ASTRAEUS Thruster Element), which was developed at the Jet Propulsion Laboratory and was recently licensed to ExoTerra Resource for flight production (renamed Halo12). In 2020-2021, the thruster successfully completed a 7205-hour wear test at operating powers from 200-1350 W, processing over 100 kg of xenon propellant and producing 1.55 MN-s total impulse with no measurable degradation in performance. The wear test is being extended to further demonstrate the service life capability of the thruster. In separate tests, prot-flight MaSMi hollow cathodes demonstrated \u3e 25000 ignition cycles and \u3e 13000 hours of operation at 4 A discharge current, and a set of three MaSMi electromagnets underwent \u3e 3000 deep thermal cycles (-123 °C to 495 °C). Laser-induced fluorescence (LIF) measurements of ion velocities and plasma modeling with Hall2De, a widely published numerical plasma code, have been carried out to elucidate the physical mechanisms driving pole erosion trends observed in thruster wear testing. Survival probabilities for micrometeoroid impacts and other random failure modes in flight were also analyzed

D2.1 Analysis of existing MOOC platforms and services

The main objective of this task is to analyze features and services of MOOC platforms that are used in ECO and, secondly, in other commonly used MOOC platforms. This task takes into account the functionality that is required by the different pilots from two viewpoints: technological and pedagogical aspects. Firstly, to ensure this objective, this task performed a state-of-the-art review, mainly research papers and all annotated scientific literature. Secondly, we elaborate a Competitive Analysis Checklist for MOOC platforms. An approach based on technological and pedagogical items is suggested to define specific dimensions for this task. This Checklist will be a useful tool for evaluating MOOC platforms. Thirdly, five of the ECO platforms have been evaluated by using the authoring and delivery environment to check for the availability of features that are essential for the implementation of the pedagogical model as described in D2.1. It became clear that these platforms are not very suitable for the pedagogical model. Finally, a Guide for the Effective Creation of MOOCs has been drawn up indicating to assist course designers to compare the functionality, features, pedagogical and instructional advantages so they can choose the most suitable one for their areas of interest and needs.Part of the work carried out has been funded with support from the European Commission, under the ICT Policy Support Programme, as part of the Competitiveness and Innovation Framework Programme (CIP) in the ECO project under grant agreement n° 21127

Comet Hitchhiker: NIAC Phase 1 Final Report

Summary of Activities-Developed the Comet Hitchhiker concept, which is to hitch rides on small bodies (asteroids and comets) using a tethered spacecraft. (Section 2)-Identified five scientifically important missions that would be enabled or significantly benefited by the Comet Hitchhiker concept.The five mission concepts are: KBO rendezvous, Centaur rendezvous, Trojan rendezvous, Damocloid rendezvous, and Main asteroid belt tour to rendezvous with multiple (10) objects. (Section 3)-Derived the Space Hitchhike Equation, or "the rocket equation for hitchhiker", which relates the specific strength of tether, mass ratio, and V. (Section 4.1)-Performed in-depth feasibility analysis of the critical components of the concept through: Finite-element simulations of tether and spacecraft dynamics, as shown in Figure 1 (Section 4.4); Supercomputer simulations of the hypervelocity impact of harpoon on a small body, as shown in Figure 2. (Section 6)-Performed public outreach activities including the collaboration with a concept artist of the Museum of Science Fiction, exposure to media, and public presentations. (Section 8