Asociación entre metodología docente y satisfacción del alumno en la enseñanza

El trabajo tuvo por objetivo determinar la relación existente entre metodología docente y satisfacción del alumno en la enseñanza, en la carrera de Ingeniería en Metalurgia y de Materiales de la ESIQIE – IPN. Se hizo un estudio descriptivo relacional, con diseño transversal, prospectivo y bivariado. Se aplicaron dos cuestionarios, el primero mide la metodología que utilizan los docentes en la enseñanza, el segundo mide la percepción de los alumnos respecto a la satisfacción en la enseñanza. Los ítems se miden mediante la escala de Likert con cinco opciones. La muestra fue de 96 alumnos, no probabilística. Los datos se procesaron en el programa IBM SPSS Statistics versión 25. El análisis estadístico se realizó por medio de frecuencias, porcientos y tablas estadísticas y la prueba de Chi cuadrada para la relación. En los resultados se describen las dos variables y posteriormente se establece la relación que existe entre ambas variables.The objective of the work was to determine the relationship between teaching methodology and student satisfaction in teaching, in the Engineering course in Metallurgy and Materials of the ESIQIE - IPN.A relational descriptive study was carried out, with a transversal, prospective and bivariate design. Two questionnaires were applied. The first measures the methodology used by teachers in teaching, the second measures the perception of the students regarding the services that the ESIQIE offers them. The items are measured using the Likert scale with five options. The sample was 96 students, not probabilistic. The data was processed in the IBM SPSS Statistics version 25 program. The statistical analysis was carried out by means of frequencies, percentages and statistical tables and the Chi square test. In the results, the two variables are described and subsequently the relationship between both variables is established

Co-culture of a novel fermentative bacterium, Lucifera butyrica gen. nov. sp. nov., with the sulfur reducer Desulfurella amilsii for enhanced sulfidogenesis

Biosulfidogenesis can be used to remediate low pH and high metal content waters such as acid mine drainage and recover the present metals. The selection of a cheap electron donor for the process is important for the economic viability. In this work we isolated a novel versatile acidotolerant fermentative bacterium (strain ALET) that is able to use a great variety of substrates including glycerol. Strain ALET is an obligate anaerobe, and cells are motile, rod-shaped, spore-forming, and stain Gram-positive. Growth occurred in a pH range from 3.5 to 7 (optimum 5.5), and temperature range from 25 to 40°C (optimum 37°C). It grows by fermentation of sugars, organic acids and glycerol. It has the ability to use thiosulfate, iron and DMSO as electron acceptors. Its genome is 4.7 Mb with 5122 protein-coding sequences, and a G+C content of 46.9 mol%. Based on 16S rRNA gene sequence analysis, the closest cultured species is Propionispora hippei (91.4% 16S rRNA gene identity) from the Sporomusaceae family (Selenomonadales order, Negativicutes class, Firmicutes phylum). Based on the distinctive physiological and phylogenetic characteristics of strain ALET, a new genus and species Lucifera butyrica gen. nov., sp. nov., is proposed. The type strain is ALET (=JCM 19373T=DSM 27520T). Strain ALET is an incomplete oxidizer and acetate, among other products, accumulates during glycerol conversion. Strain ALET was used to extend the substrate range for sulfur reduction by constructing cocultures with the acetate oxidizer and sulfur reducer Desulfurella amilsii. The coculture was tested with glycerol as substrate in batch and chemostat experiments. Acetate formed by fermentation of glycerol by strain ALET resulted in sulfur reduction by D. amilsii. The coculture strategy offers good perspectives to use a wide range of cost-efficient substrates, including glycerol, to produce sulfide by specialized sulfur reducers. The recovery of heavy metals from metalliferous streams may become economically feasible by this approach.The doctoral study program was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), organization of the Brazilian Government. Research of DS, IS-A, and AS is financed by an ERC grant (Project 323009) and the Gravitation grant (SIAM 024.002.002) of the Netherlands Ministry of Education, Culture and Science and the Netherlands Science Foundation.info:eu-repo/semantics/publishedVersio

Estudio por difracción de rayos X del octamolibdato de amonio

El octamolibdato de amonio (NH₄)₄[Mo₈O₂₆]·4H₂O se preparó por primera vez y fue estudiado mediante análisis de difracción de rayos-X.Ammonium octamolybdate (NH₄)₄[Mo₈O₂₆]·4H₂O was prepared for the first time and studied by X-ray diffraction analysis

Massive Galaxies in COSMOS: Evolution of Black hole versus bulge mass but not versus total stellar mass over the last 9 Gyrs?

We constrain the ratio of black hole (BH) mass to total stellar mass of type-1 AGN in the COSMOS survey at 1<z<2. For 10 AGN at mean redshift z~1.4 with both HST/ACS and HST/NICMOS imaging data we are able to compute total stellar mass M_(*,total), based on restframe UV-to-optical host galaxy colors which constrain mass-to-light ratios. All objects have virial BH mass-estimates available from the COSMOS Magellan/IMACS and zCOSMOS surveys. We find zero difference between the M_BH--M_(*,total)-relation at z~1.4 and the M_BH--M_(*,bulge)-relation in the local Universe. Our interpretation is: (a) If our objects were purely bulge-dominated, the M_BH--M_(*,bulge)-relation has not evolved since z~1.4. However, (b) since we have evidence for substantial disk components, the bulges of massive galaxies (logM_(*,total)=11.1+-0.25 or logM_BH~8.3+-0.2) must have grown over the last 9 Gyrs predominantly by redistribution of disk- into bulge-mass. Since all necessary stellar mass exists in the galaxy at z=1.4, no star-formation or addition of external stellar material is required, only a redistribution e.g. induced by minor and major merging or through disk instabilities. Merging, in addition to redistributing mass in the galaxy, will add both BH and stellar/bulge mass, but does not change the overall final M_BH/M_(*,bulge) ratio. Since the overall cosmic stellar and BH mass buildup trace each other tightly over time, our scenario of bulge-formation in massive galaxies is independent of any strong BH-feedback and means that the mechanism coupling BH and bulge mass until the present is very indirect.Comment: Published in ApJL; 7 pages, 2 figures; updated to accepted version (methods changed, results unchanged

Síntesis y caracterización de Hexamolibdometalatos(III) de tetraamminozinc

Fueron sintetizados y estudiados por análisis elemental, termogravimétrico y fases por rayos X los compuestos hexamolibdocobaltato(III) y hexamolibdocromato(III) de tetraamminozinc con fórmulas [Zn(NH₃)₄]∙H[CoMo₆O₁₈(OH)₆]∙6H₂O (I) y [Zn(NH₃)₄]∙H[CrMo₆O₁₈ (OH) ₆]∙6H₂O (II). Los cristales de I son monoclínicos, a= 16.18, b = 5.58, c = 12.23 Å, β = 118.86º, V= 958.50 ų ρ calc = 3.17g/cm3, Z = 1. Los cristales del compuesto II son moclínicos, a=16.23 Å, b=5.34 Å, c= 12.36 Å, β =119.54°,v = 978.64 ų, ρ calc =3.34g/ cm3, Z = 1. Los compuestos I y II fueron empleados como catalizadores en reacciones de oxidación del gas natural.The compounds hexamolibdocobaltate (III) and hexamolibdocromate (III) of tetraaminozinc with formulas [Zn(NH₃)₄]∙H[CoMo₆O₁₈(OH)₆]∙6H₂O (I) and [Zn(NH₃)₄]∙H[CrMo₆O₁₈ (OH) ₆]∙6H₂O (II). were synthesized and studied by elemental, thermogravimetric and X-ray analysis .. The crystals of I are monoclinic, a = 16.18, b = 5.58, c = 12.23 Å, β = 118.86°, V = 958.50 ų, ρ calc = 3.17g/cm3, Z = 1. The crystals of compound II are monoclinic, a=1623 Å, b=534 Å c= 12.36 Å, β = 119.54º V=978.64 ų, ρ calc =334 g/ cm3, Z = 1. Compounds I and II were used as catalysts in mild natural gas oxidation reactions

Síntesis y caracterización de Hexamolibdocromato (III) de tetraamminoníquel (II) y tetraamminocobalto (II)

Los compuestos hexamolibdocromato(III) de tetraamminoníquel(II), compuesto (I)[Ni(NH₃)₄]H[CrMo₆O₁₈ (OH) ₆]∙10H₂O y hexamolibdocromato(III) de tetraamminocobalto(II), compuesto (II) [Co(NH₃)₄]H[CrMo₆O₁₈ (OH) ₆]∙6H₂O fueron sintetizados y estudiados por espectrometría de masas, difracción de rayos X, espectroscopía infrarroja y termogravimetría. Los cristales del compuesto (I) son triclínicos: a = 17.67, b = 14.87, c = 10.54 Å, α = 131.81, β = 66.08, γ = 138.42°, V = 1345.09 Å₃, ρ calc = 3.067 g/cm³, Z = 2. Los cristales del compuesto (II) son monoclínicos: a = 16.97, b = 5.61, c= 12.36 Å, β = 119.89°, V = 1100.12 Å₃, ρcalc = 2.29g/cm³, Z = 1.The hexamolibdocromato (III) compounds of tetraamminonickel (II), compound (I) [Ni(NH₃)₄]H[CrMo₆O₁₈ (OH) ₆]∙10H₂O and hexamolibdocromate (III) of tetraamminocobalto(II), compound (II) [Co(NH₃)₄]H[CrMo₆O₁₈ (OH) ₆]∙6H₂O were synthesized and studied by mass spectrometry, X-ray diffraction, infrared spectroscopy and thermogravimetry. The crystals of compound (I) are triclinic: a = 17.67, b = 14.87, c = 10.54 Å, α = 131.81, β = 66.08, γ = 138.42°. V = 1345.09 Å₃, ρ calc = 3.067 g/cm³, Z = 2. The crystals of compound II are monoclinic: a = 16.97, b = 5.61, c = 12.36 Å, β = 119.89 °, V = 1100.12 Å₃, ρ calc = 2.29g / cm³, Z = 1

Síntesis y caracterización de hexamolibdocobaltato de glicina

El complejo hidratado hexamolibdocobaltato ácido de glicina con fórmula (H₃NCH₂СOO)₂ (H₃O)₄ [CoMo₆O₁₈(OH)₆]∙4H₂O (I) fue sintetizado y caracterizado mediante difracción de rayos X, de cristal único, espectroscopia infrarroja y resonancia magnética nuclear. El complejo cristaliza en la estructura monoclínica, grupo espacial P21/m los parámetros de la celda elemental: a=11.031 (2) Å, b=12.055(2) Å, c = 12.492 (3) Å, β = 94.18 (3)°, V = 1656.8 (6) Å₃, p cal = 2.652 mg/m₃, Z = 2.The acid complex glycine hexamolydocobaltate (H₃NCH₂СOO)₂ (H₃O)₄ [CoMo₆O₁₈(OH)₆]∙4H₂O (I) was synthesized and investigated by X-ray diffraction, IR and NMR spectroscopy. The complex crystallizes in a monoclinic structure, space group P21/m; Unitary cell parameters: a = 11,031 (2) Å, b = 12,055 (2) Å, c = 12,492 (3) Å, β = 94.18 (3)°, V = 1656.8 (6) Å₃, ρ with = 2,652 mg / m₃, Z = 2

First results of the 241Am(n,f) cross section measurement at the Experimental Area 2 of the n_TOF facility at CERN

Feasibility, design and sensitivity studies on innovative nuclear reactors that could address the issue of nuclear waste transmutation using fuels enriched in minor actinides, require high accuracy cross section data for a variety of neutron-induced reactions from thermal energies to several tens of MeV. The isotope 241Am (T1/2= 433 years) is present in high-level nuclear waste (HLW), representing about 1.8 % of the actinide mass in spent PWR UOx fuel. Its importance increases with cooling time due to additional production from the β-decay of 241Pu with a half-life of 14.3 years. The production rate of 241 Am in conventional reactors, including its further accumulation through the decay of 241Pu and its destruction through transmutation/incineration are very important parameters for the design of any recycling solution. In the present work, the 241 Am(n,f) reaction cross-section was measured using Micromegas detectors at the Experimental Area 2 of the n_TOF facility at CERN. For the measurement, the 235U(n,f) and 238U(n,f) reference reactions were used for the determination of the neutron flux. In the present work an overview of the experimental setup and the adopted data analysis techniques is given along with preliminary results