Novel post-processing procedure to enhance casting molds manufactured by binder jetting AM

The significant improvements made in additive manufacturing (AM) techniques since their beginnings, coupled with its intrinsic advantages, have resulted in a technology that stands out as most suitable for applications in leading sectors today. In addition to some of the properties of the parts, there are also some inherent aspects of AM techniques that hinder their applicability. In this respect, the application of calcium sulfate parts manufactured by binder jetting (BJ), as expendable casting elements, is limited by both the high quantity of volatile substances, due to the BJ process, and their low compression resistance. In this work, a novel part post-processing procedure is presented. This procedure consists of applying various heat treatments, in combination with a vacuum infiltration process using an Epsom salt solution. The procedure reduces the volatile content of BJ AM parts and enhances the compression strength with little modification to the part geometry. This post-processing substantially improves the applicability of BJ AM parts as expendable casting elements. After presenting this novel procedure and analyzing the significant enhancement of the properties of the AM calcium sulfate parts (i.e. permeability, the reduction of volatile content and reduction of compressive strength), a case study is presented with an expendable mold for aluminum casting. This procedure allows for a safer casting process, improves the part’s surface quality and reduces the internal porosity of the cast parts.S

Efectividad de AQ10 (Ampelomyces quisqualis cepa M-10) en el control biológico del oídio (Podosphaera xanthii).

El oídio de las cucurbitáceas es una enfermedad que disminuye la productividad y provoca pérdidas económicas. El control químico, incrementa costos de roducción y la resistencia de hongos; por ello se buscan alternativas como el control biológico.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI

Antagonismo in vitro de diferentes aislados de Trichoderma spp., sobre Macrophomina phaseolina.

Con este trabajo se concluye que la cepa de Trichoderma MS19 tiene un alto potencial antagónico con respecto a las demás cepas al considerar su tasa de crecimiento y porcentaje de inhibición de Macrophomina phaseolina.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI

Standard and Embedded Solitons in Nematic Optical Fibers

A model for a non-Kerr cylindrical nematic fiber is presented. We use the multiple scales method to show the possibility of constructing different kinds of wavepackets of transverse magnetic (TM) modes propagating through the fiber. This procedure allows us to generate different hierarchies of nonlinear partial differential equations (PDEs) which describe the propagation of optical pulses along the fiber. We go beyond the usual weakly nonlinear limit of a Kerr medium and derive an extended Nonlinear Schrodinger equation (eNLS) with a third order derivative nonlinearity, governing the dynamics for the amplitude of the wavepacket. In this derivation the dispersion, self-focussing and diffraction in the nematic are taken into account. Although the resulting nonlinear $PDE$ may be reduced to the modified Korteweg de Vries equation (mKdV), it also has additional complex solutions which include two-parameter families of bright and dark complex solitons. We show analytically that under certain conditions, the bright solitons are actually double embedded solitons. We explain why these solitons do not radiate at all, even though their wavenumbers are contained in the linear spectrum of the system. Finally, we close the paper by making comments on the advantages as well as the limitations of our approach, and on further generalizations of the model and method presented.Comment: "Physical Review E, in press

Thermal characterization of Montmorillonite clays saturated with various cations

Emanation thermal analysis (ETA), thermogravimetry and high temperature XRD were used to characterize the thermal behavior during dehydration of natural Na montmorillonite (Upton Wyoming, USA) and homoionic montmorillonite (MMT) samples saturated with different cations, i.e. Li+, Cs+, NH 4 +, Mg2+ and Al3+. ETA results characterized radon mobility and microstructure changes that accompanied the mass loss of the samples due to dehydration on heating in air. A collapse of interlayer space between the silicate sheets after water release from the MMT samples was characterized by a decrease of the radon release rate, ΔE. Decreases in c-axis basal spacing (d 001) values determined from XRD patterns for the different montmorillonite samples follow the sequence: Mg−MMT>Al−MMT>Li−MMT>Na−MMT>NH4−MMT>Cs−MMT The decrease of the radon release rate (ΔE) determined by ETA that characterized microstructure changes due to collapse of interlayer space corresponded well to differences in the c-axis basal spacing (Δd 001) values determined from the XRD patterns before and after samples dehydration.Peer Reviewe

Biocontrol de Rhizoctonia solani en papa, 2. Aplicaciones en campo.

Con el objeto de evaluar hongos a Rhizoctonia solani en papa bajo condiciones de campo se llevaron a cabo experimentos en el Centro de Investigación Tibaitatá, localizado en Mosquera, Cundinamarca. Se encontró que el menor porcentaje de tubérculos afectados por el patógeno acurría cuando se utilizaba una mezcla de Trichoderma sp., T. por. Koningii 1, T. por. Koningii 2 y Gliocladium sp. Se pudo establecer que en semestres de alta precipitación T. por. Koningii 1 (Monserrate 1) disminuye su efectividad biocontroladora y que la eficiencia antagónica de los hongos probados es mayor en las condiciones controladas de invernadero en el campo, donde factores ambientales adversos parecen reducir su efectividadPapa-Solanum tuberosu

Antagonismo in vitro de diferentes aislados de Trichoderma spp., sobre Macrophomina phaseolina.

Con este trabajo se concluye que la cepa de Trichoderma MS19 tiene un alto potencial antagónico con respecto a las demás cepas al considerar su tasa de crecimiento y porcentaje de inhibición de Macrophomina phaseolina.CONACYT - Consejo Nacional de Ciencias y TecnologíaPROCIENCI

Efficacy of the Vaccine Candidate Based on the P0 Peptide against Dermacentor nitens and Ixodes ricinus Ticks

(This article belongs to the Collection Advances in Tick Research)The control of ticks through vaccination offers a sustainable alternative to the use of chemicals that cause contamination and the selection of resistant tick strains. However, only a limited number of anti-tick vaccines have reached commercial realization. In this sense, an antigen effective against different tick species is a desirable target for developing such vaccines. A peptide derived from the tick P0 protein (pP0) conjugated to a carrier protein has been demonstrated to be effective against the Rhipicephalus microplus, Rhipicephalus sanguineus, and Amblyomma mixtum tick species. The aim of this work was to assess the efficacy of this peptide when conjugated to the Bm86 protein against Dermacentor nitens and Ixodes ricinus ticks. An RNAi experiment using P0 dsRNA from I. ricinus showed a dramatic reduction in the feeding of injected female ticks on guinea pigs. In the follow-up vaccination experiments, rabbits were immunized with the pP0-Bm86 conjugate and challenged simultaneously with larvae, nymphs, and the adults of I. ricinus ticks. In the same way, horses were immunized with the pP0-Bm86 conjugate and challenged with D. nitens larva. The pP0-Bm86 conjugate showed efficacies of 63% and 55% against I. ricinus and D. nitens ticks, respectively. These results, combined with previous reports of efficacy for this conjugate, show the promising potential for its development as a broad-spectrum anti-tick vaccine.This research was funded by the Center for Genetic Engineering and Biotechnology, Havana, Cuba, the Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Portugal, and the Czech Science Foundation grant no. 20-05736S. Mobility was supported by the CYTED Network INCOGARR 110RT0541.info:eu-repo/semantics/publishedVersio

Increasing number of long-lived ancestors marks a decade of healthspan extension and healthier metabolomics profiles

Globally, the lifespan of populations increases but the healthspan is lagging behind. Previous research showed that survival into extreme ages (longevity) clusters in families as illustrated by the increasing lifespan of study participants with each additional long-lived family member. Here we investigate whether the healthspan in such families follows a similar quantitative pattern using three-generational data from two databases, LLS (Netherlands), and SEDD (Sweden). We study healthspan in 2143 families containing index persons with 26 follow-up years and two ancestral generations, comprising 17,539 persons. Our results provide strong evidence that an increasing number of long-lived ancestors associates with up to a decade of healthspan extension. Further evidence indicates that members of long-lived families have a delayed onset of medication use, multimorbidity and, in mid-life, healthier metabolomic profiles than their partners. We conclude that both lifespan and healthspan are quantitatively linked to ancestral longevity, making family data invaluable to identify protective mechanisms of multimorbidity. Development and application of statistical models for medical scientific researc

The Physics of turbulent and dynamically unstable Herbig-Haro jets

The overall properties of the Herbig-Haro objects such as centerline velocity, transversal profile of velocity, flow of mass and energy are explained adopting two models for the turbulent jet. The complex shapes of the Herbig-Haro objects, such as the arc in HH34 can be explained introducing the combination of different kinematic effects such as velocity behavior along the main direction of the jet and the velocity of the star in the interstellar medium. The behavior of the intensity or brightness of the line of emission is explored in three different cases : transversal 1D cut, longitudinal 1D cut and 2D map. An analytical explanation for the enhancement in intensity or brightness such as usually modeled by the bow shock is given by a careful analysis of the geometrical properties of the torus.Comment: 17 pages, 10 figures. Accepted for publication in Astrophysics & Spac