Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción Animal

Biomorphic SiC/Si compounds were fabricated from copaiba wood (Copaifera officinalis, natural wood native to Peru), by reactive infiltration of molten silicon in a porous carbon preform obtained by a controlled pyrolysis process of wood. Structural and microstructural characterization tests by X-ray diffraction and scanning electron microscopy, respectively, revealed, on the one hand, the presence of crystalline phases of SiC, Si and C, and on the other, the typical morphology of this type of material, which it consists of a continuous SiC scaffold with elongated channels in the direction of tree growth and the presence of residual Si and C located mainly in the porosities of the material. The mechanical behavior in uniaxial compression was also studied at a constant compression rate of 0.05 mm/min and as a function of temperature (from ambient to 1400 ºC) and test atmosphere (ambient a...

We report photometry of Type Ia SN 2025qpk gathered with the OAUNI 51cm telescope at Huancayo Observatory, Peru. CCD imaging in R filter was performed on two consecutive nights under nonphotometric conditions with airmasses lower than 1.3. The integration time was 60x20s=1200s for all observations. Our measurements yielded: Date (UT) | filter | seeing (") | mag, 2025-07-24.333 | R | 1.8 | 14.56 +/- 0.01, 2025-07-25.138 | R | 2.3 | 14.49 +/- 0.01. UCAC4 field stars were used for the zero point calibration. Our observations are ~17 days after the discovery (TNSTR-2025-2620). The OAUNI project is supported by UNI, TWAS, IGP and ProCiencia-Concytec (Convenio 133-2020 Fondecyt).

We report photometric observations of Type Ia supernovae SN 2025plf and SN 2025rbs, obtained with the OAUNI 51cm telescope at Huancayo Observatory, Peru. CCD imaging was carried out in R filter on 2025-07-25 (UT) under non-photometric conditions, with airmasses lower than 1.5. The integration times were 60x20s=1200s for SN 2025plf and 45x20s=900s for SN 2025rbs. Our measurements yielded: SN | Date (UT) | filter | seeing (") | mag, 2025plf | 2025-07-25.261 | R | 1.9 | 15.61 +/- 0.11, 2025rbs | 2025-07-25.281 | R | 2.0 | 12.19 +/- 0.01. Zero-point calibration in both cases was performed using UCAC4 field stars. The observations were gathered ~25 days after the discovery of SN 2025plf and ~11 days after that of SN 2025rbs. The OAUNI project is supported by UNI, TWAS, IGP, and ProCienciaˇConcytec (Convenio 133-2020 Fondecyt).

The possibility of using biomass as a precursor of silicon carbide (SiC) has been studied for many years. In this research, reaction-formed silicon carbide was synthesized from sawdust residues of Peruvian wood. Residues were packed into cylindrical solid pieces through hot pressing and they were subsequently pyrolyzed in an inert atmosphere and infiltrated with metallic silicon in a vacuum atmosphere. SiC pieces were obtained with silicon remaining in their pores, so a chemical attack was performed to clean the samples. Mechanical and thermomechanical properties were evaluated in different environments to know the behavior of SiC through compression tests. The highest values were obtained at room temperature under normal conditions, a maximum stress of 686 MPa was achieved. In all cases, the samples had a fragile behavior as expected. In thermomechanical tests it was observed that resis...

We report new photometry of Type II SN 2024iss gathered with the OAUNI 51cm telescope at Huancayo Observatory, Peru. CCD imaging in R filter was performed on four consecutive nights under non-photometric conditions with the target on higher airmasses. The integration time was 80x20s=1600s in each observation. Our measurements yielded: Date (UT) | filter | seeing (") | mag, 2024-07-03.124 | R | 14.70 +/- 0.02, 2024-07-04.129 | R | 14.72 +/- 0.02, 2024-07-05.112 | R | 14.76 +/- 0.01, 2024-07-06.097 | R | 14.77 +/- 0.01. UCAC4 field stars were used for the zero point calibration. Our observations are ~7.3 weeks after the GOTO detection. The OAUNI project is supported by UNI, TWAS, IGP and ProCiencia-Concytec (Convenio 133-2020 Fondecyt).

We report photometry of Type II SN 2024iss gathered with the OAUNI 51cm telescope at Huancayo Observatory, Peru. CCD imaging in R filter was performed on three consecutive nights under non-photometric conditions with airmasses lower than 1.5. The integration time was 70x20s=1400s in each observation. Our measurements yielded: Date (UT) | filter | seeing (") |mag, 2024-06-07.102 | R | 2.6 |13.40 +/- 0.02, 2024-06-08.093 | R | 2.6 | 13.49 +/- 0.02, 2024-06-09.094 | R | 2.8 | 13.59 +/- 0.02. UCAC4 field stars were used for the zero point calibration. Our observations are ~3.7 weeks after the GOTO detection. The OAUNI project is supported by UNI, TWAS, IGP and ProCiencia-Concytec (Convenio 133-2020 Fondecyt).

We report photometry of Type II SN 2024ggi gathered with the OAUNI 51cm telescope (arXiv:1512.03104) at Huancayo Observatory, Peru. CCD imaging in R filter was performed on five consecutive nights under nonˇphotometric conditions with airmasses lower than 1.6. The integration time was 50x20s=1000s in the first observation and 60x20s=1200s for the rest. Our measurements yielded: Date (UT) | filter | seeing (") | mag, 2024-06-05.108 | R | 3.2 | 12.27 +/- 0.06, 2024-06-06.080 | R | 2.6 | 12.25 +/- 0.06, 2024-06-07.064 | R | 2.8 | 12.27 +/- 0.06, 2024-06-08.061 | R | 2.7 | 12.27 +/- 0.06, 2024-06-09.062 | R | 2.9 | 12.28 +/- 0.06. UCAC4 field stars were used for the zero point calibration. Our observations are ~7.9 weeks after ATLAS discovery (TNSAN-2024-100). The OAUNI project is supported by UNI, TWAS, IGP and ProCiencia-Concytec (Convenio 133-2020 Fondecyt).

We report photometry of Type II SN 2024jlf gathered with the OAUNI 51cm telescope (arXiv:1512.03104) at Huancayo Observatory, Peru. CCD imaging in R filter was performed on five consecutive nights under non-photometric conditions with airmasses lower than 1.3. The integration time was 40x20s=800s for all observations. Our measurements yielded: Date (UT) | filter | seeing (") | mag, 2024-06-05.056 | R | 2.5 | 14.71 +/- 0.01, 2024-06-06.024 | R | 2.7 | 14.57 +/- 0.03, 2024-06-07.013 | R | 2.9 | 14.45 +/- 0.03, 2024-06-08.010 | R | 2.7 | 14.54 +/- 0.02, 2024-06-09.005 | R | 2.5 | 14.66 +/- 0.02. UCAC4 field stars were used for the zero point calibration. Our first observation is ~8 days after ZTF discovery. The OAUNI project is supported by UNI, TWAS, IGP and ProCiencia-Concytec (Convenio 133-2020 Fondecyt).

En este trabajo se determinaron los parámetros para la limpieza por ablación láser de contaminantes depositados mediante atracción electrostática sobre sustratos de láminas de acetato de celulosa (OHP) y su análisis mediante la medición de la transmitancia de la superficie irradiada en función de la energía por pulso de un láser Nd:YAG. La energía fue controlada mediante el tiempo de retraso del Q-switch usando longitudes de onda en la región infrarroja de 1064 nm y luz visible verde de 532 nm. Se utilizó un máximo de 10 pulsos láser con una frecuencia de 1 Hz sobre lo s sustratos con contaminantes con 9 μm y 11 μm de espesor. Se encontró que para la limpieza láser sin daños de sustratos de la s láminas OHP, es conveniente usar una longitud de onda de 1064 nm, con una fluencia de 0.4 J/cm2 y usando un máximo de 6 pulsos. Se verificaron las ventajas de la radiación...

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción Animal

Rice feeds more than 50% of the population worldwide, representing a great energy contribution in low-income families. The exaggerated use of synthetic chemical fertilizers to maintain high levels of yield causes alterations in the physical, chemical and biological quality of the soils. A sustainable alternative is the use of beneficial microorganisms that promote plant growth in crops. The objective of the study was to isolate and evaluate the Plant Growth Promoting (PGP) traits of rhizospheric rice bacteria in soils of the San Martin region, evaluate the effect of promoting growth in rice under pot experiments conditions and finally evaluate the effect of selected strains on the yield under different doses of nitrogen fertilizer under field conditions. Initially, 27 strains were selected for their diazotrophic characteristics and characterized by PGP traits. Through a multivariate anal...

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción Animal

Geopolymers are a class of inorganic synthetic materials that in recent years have received extensive interest of the scientific community, mainly due to the variety of applications in which they can be used. The synthesis of these materials is based on a chemical process called geopolymerization, which consists of the alkaline activation of amorphous alumina and silica oxides present in many natural raw materials and industrial solid waste. Therefore, the present work proposes the use of inorganic mining residues (mine tailings) from gold mining in the southern region of Peru, for the manufacture of geopolymeric concrete. The first part of the research focused on the physical, structural and microstructural characterization of the raw material (fine sand and mining tailings), then the volumetric matrix of mixtures for five types of geopolymer concrete was determined. Cylindrical samples...

Geopolymeric materials have recently been considered a revolutionary class of materials, due to the diversity of applications where they can be used, this derived from their good mechanical resistance, thermochemical stability and good fire resistance. From 1970 to the present, a notable increase has been observed in the number of scientific publications dealing with the synthesis and applications of geopolymeric materials with industrial application. Several publications have reported geopolymers as alternative materials to Portland cement, which will allow having a green construction industry in the coming years. The elaboration of geopolymeric materials is relatively simple, beginning with the identification of a source rich in amorphous aluminosilicates and a hardening compound (mainly alkaline in nature) which are properly mixed until a homogeneous and workable paste is obtained, th...