Cohesive mixed-mode damage model applied to the simulation of the mechanical behaviour of a repaired sandwich beam

The behaviour of a repaired sandwich beam loaded under four point bending is simulated using theABAQUS® software. Both overlap and scarf repair, suitable for sandwich structures, were simulatedconsidering two dimensional nonlinear material and geometrical analysis. Special developed interfacefinite elements including a trapezoidal cohesive mixed-mode damage model appropriate for ductileadhesives were used in order to simulate the adhesive layer. The proposed model is intended to replacethe continuum finite elements traditionally used to simulate the adhesive layer, thus reducing thecomputational effort necessary to obtain results. Double Cantilever Beam (DCB) and End NotchedFlexure (ENF) tests were used to obtain the cohesive laws of the adhesive in pure modes I and II,respectively. The fracture energies (JIc and JIIc) are obtained using a new data reduction scheme based oncrack equivalent concept allowing overcoming crack monitoring difficulties during propagation in thesefracture characterization tests. The remaining cohesive parameters (1,I, 1,II, 2,I, 2,II)are obtained usingan inverse method, which is based on the fitting of the numerical and experimental P- curves by a finetuning process. This procedure allows fixing the referred cohesive parameters to be used in the stressanalyses and strength predictions of repaired sandwiches. The numerical model allowed the simulation ofdamage initiation and growth. Geometric changes, such as patch overlap length and scarf angle wereconsidered in the analysis in order to assess their influence on the repair efficiency. Conclusions weredrawn about design guidelines of sandwich composite material repair

Magnon delocalization in ferromagnetic chains with long-range correlated disorder

We study one-magnon excitations in a random ferromagnetic Heisenberg chain with long-range correlations in the coupling constant distribution. By employing an exact diagonalization procedure, we compute the localization length of all one-magnon states within the band of allowed energies $E$. The random distribution of coupling constants was assumed to have a power spectrum decaying as $S(k)\propto 1/k^{\alpha}$. We found that for $\alpha < 1$, one-magnon excitations remain exponentially localized with the localization length $\xi$ diverging as 1/E. For $\alpha = 1$ a faster divergence of $\xi$ is obtained. For any $\alpha > 1$, a phase of delocalized magnons emerges at the bottom of the band. We characterize the scaling behavior of the localization length on all regimes and relate it with the scaling properties of the long-range correlated exchange coupling distribution.Comment: 7 Pages, 5 figures, to appear in Phys. Rev.

Modelação por elementos finitos do processo de furação em laminados de carbono/epóxido

Neste trabalho apresentam-se os resultados obtidos em simulações numéricas dafuração de laminados de carbono/epóxido usando elementos sólidos tridimensionais dosoftware ABAQUS® Explicit. O início e propagação do dano são simulados recorrendo ainstruções específicas do programa, bem como a remoção dos elementos ao longo doprocesso. Os resultados obtidos numericamente são comparados com resultadosexperimentais obtidos previamente pelos autores. Verifica-se uma boa concordância entre osresultados numéricos e os experimentais, confirmando a validade do modelo proposto

Use of retinoids during oocyte maturation diminishes apoptosis in caprine embryos

Exposure of caprine oocytes and embryos to retinoids enhances embryonic development, but the mechanisms governing this phenomenon have not been characterised. The aim of the present study was to evaluate if the incidence of apoptosis is affected by the addition of retinyl acetate (RAc) and 9-cis-retinoic acid (RA) during in vitro maturation (IVM) of caprine oocytes. Embryonic development was recorded on days 3 and 8 post-fertilisation, and apoptosis was measured by caspase activity and DNA fragmentation (TUNEL assay). Control zygotes had lower capacity to cleave and reach the blastocyst stage (24.45 ± 2.32 and 5.32 ± 0.81, respectively) than those of RAc- (29.96 ± 1.62 and 7.94 ± 0.93, respectively) and RA-treated groups (30.12 ± 1.51 and 7.36 ± 1.02, respectively). Oocytes and blastocysts positive for TUNEL assay were more frequent, respectively, in the controls (8.20 ± 0.78, 8.70 ± 1.05) than in RAc (5.60 ± 0.52, 4.80 ± 0.51) and RA (6.40 ± 0.69, 5.40 ± 0.69). Caspase activity did not differ between control oocytes (7.20 ± 0.91), RAc (6.60 ± 0.68) and RA (7.30 ± 0.67), but it was reduced in RAc- (5.05 ± 0.62) and RA-treated blastocysts (5.75 ± 0.22) compared to controls (8.35 ± 0.71). These results indicate that the addition of retinoids during IVM increases the developmental potential of goat embryos with a concomitant reduction in apoptosis rates

Dissecting EPPIN protease inhibitor domains in sperm motility and fertilizing ability: Repercussions for male contraceptive development

EPPIN (epididymal protease inhibitor) is a mammalian conserved sperm-binding protein displaying an N-terminal WFDC (whey-acidic protein four-disulfide core) and a C-terminal Kunitz protease inhibitor domains. EPPIN plays a key role in regulating sperm motility after ejaculation via interaction with the seminal plasma protein SEMG1 (semenogelin-1). EPPIN ligands targeting the SEMG1 binding site in the Kunitz domain are under development as male contraceptive drugs. Nevertheless, the relative contributions of EPPIN WFDC and Kunitz domains to sperm function remain obscure. Here, we evaluated the effects of antibodies targeting specific epitopes in EPPIN's WFDC (Q20E antibody, Gln20-Glu39 epitope) and Kunitz (S21C and F21C antibodies, Ser103-Cys123 and Phe90-C110 epitopes, respectively) domains on mouse sperm motility and fertilizing ability. Computer-assisted sperm analysis showed that sperm co-incubation with S21C antibody (but not F21C antibody) lowered progressive and hyperactivated motilities and impaired kinematic parameters describing progressive (straight-line velocity; VSL, average path velocity; VAP and straightness; STR) and vigorous sperm movements (curvilinear velocity; VCL, amplitude of lateral head movement; ALH, and linearity; LIN) compared with control. Conversely, Q20E antibody-induced milder inhibition of progressive motility and kinematic parameters (VAP, VCL and ALH). Sperm co-incubation with S21C or Q20E antibodies affected in vitro fertilization as revealed by reduced cleavage rates, albeit without changes in capacitation-induced tyrosine phosphorylation. In conclusion, we show that targeting specific epitopes in EPPIN Kunitz and WFDC domains inhibits sperm motility and capacitation-associated events, which decrease their fertilizing ability; nevertheless, similar observations in vivo remain to be demonstrated. Simultaneously targeting residues in S21C and Q20E epitopes is a promising approach for the rational design of EPPIN-based ligands with spermostatic activity.Fil: Silva, Alan A. S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Raimundo, Tamiris R. F.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Mariani, Noemia A. P.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Kushima, Hélio. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Avellar, Maria Christina W.. Universidade Federal de Sao Paulo; BrasilFil: Buffone, Mariano Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Paula Lopes, Fabíola F.. Universidade Federal de Sao Paulo; BrasilFil: Moura, Marcelo T.. Universidade Federal de Sao Paulo; BrasilFil: Silva, Erick J. R.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

Conceiving a Digital Twin for a Flexible Manufacturing System

Digitization and virtualization represent key factors in the era of Industry 4.0. Digital twins (DT) can certainly contribute to increasing the efficiency of various productive sectors as they can contribute to monitoring, managing, and improvement of a product or process throughout its life cycle. Although several works deal with DTs, there are gaps regarding the use of this technology when a Flexible Manufacturing System (FMS) is used. Existing work, for the most part, is concerned with simulating the progress of manufacturing without providing key production data in real-time. Still, most of the solutions presented in the literature are relatively expensive and may be difficult to implement in most companies, due to their complexity. In this work, the digital twin of an FMS is conceived. The specific module of an ERP (Enterprise Resources Planning) system is used to digitize the physical entity. Production data is entered according to tryouts performed in the FMS. Sensors installed in the main components of the FMS, CNC (computer numerical control) lathe, robotic arm, and pallet conveyor send information in real-time to the digital entity. The results show that simulations using the digital twin present very satisfactory results compared to the physical entity. In time, information such as production rate, queue management, feedstock, equipment, and pallet status can be easily accessed by operators and managers at any time during the production process, confirming the MES (manufacture execution system) efficiency. The low-cost hardware and software used in this work showed its feasibility. The DT created represents the initial step towards designing a metaverse solution for the manufacturing unit in question, which should operate in the near future as a smart and autonomous factory model.Thanks are due to Elkartek 2022 project LANVERSO, and in some sections (simulations) to Basque government university group IT 1573-22

Notch Inhibition Allows Oncogene-Independent Generation of iPS Cells

The reprogramming of somatic cells to pluripotency using defined transcription factors holds great promise for biomedicine. However, human reprogramming remains inefficient and relies either on the use of the potentially dangerous oncogenes ​KLF4 and ​CMYC or the genetic inhibition of the tumor suppressor gene ​p53. We hypothesized that inhibition of signal transduction pathways that promote differentiation of the target somatic cells during development might relieve the requirement for non-core pluripotency factors during induced pluripotent stem cell (iPSC) reprogramming. Here, we show that inhibition of Notch greatly improves the efficiency of iPSC generation from mouse and human keratinocytes by suppressing ​p21 in a ​p53-independent manner and thereby enriching for undifferentiated cells capable of long-term self-renewal. Pharmacological inhibition of Notch enabled routine production of human iPSCs without ​KLF4 and ​CMYC while leaving ​p53 activity intact. Thus, restricting the development of somatic cells by altering intercellular communication enables the production of safer human iPSCs.Molecular and Cellular BiologyStem Cell and Regenerative Biolog

Comparte la felicidad, educando sobre sexualidad con ciudadanos y ciudadanas habitantes de calle

Curso de Especial InterésLos habitantes de calle (en adelante CHC) se han convertido en una problemática social debido a la desarticulación, violencia y pobreza de la sociedad colombiana. A partir de esta situación se diseñó y elaboró la cartilla “Comparte la felicidad, educando sobre sexualidad con Ciudadanos y Ciudadanas Habitantes de calle” que aborda los cuatro holones de la sexualidad: Vinculación afectiva, erotismo, género y reproductividad, con el objetivo de promover la salud sexual y reproductiva, y la prevención de Infecciones de transmisión sexual, incluido el VIH/SIDA. Para identificar el contenido de la cartilla se realizó una entrevista estructurada de la cual se obtuvo la información a incluir en la cartilla, posteriormente validada en la unidad OASIS.Curso de Especial Interés1. Resumen 2. Justificación 3. Marco teórico 4. Objetivos de la investigación 5. Métodología 6. Estudio de mercado 7. Resultados 8. Discusión 9. Conclusiones 10. Recomendaciones 11. Referencias 12. ApéndicesPregradoPsicólog

Forward Neutral Pion Transverse Single Spin Asymmetries in p+p Collisions at \sqrt{s}=200 GeV

We report precision measurements of the Feynman-x dependence, and first measurements of the transverse momentum dependence, of transverse single spin asymmetries for the production of \pi^0 mesons from polarized proton collisions at \sqrt{s}=200 GeV. The x_F dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the p_T dependence at fixed x_F are not consistent with pQCD-based calculations.Comment: 6 pages, 4 figure