Cristobal Montalba

Dr. Cristobal Montalba


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 May 2019 in Discover Nano
Verified
Journal Article
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AJAndres Jaramillo
Andres Jaramillo
SRS. A. Riquelme
S. A. Riquelme
GSGabriela Sánchez-Sanhueza
Gabriela Sánchez-Sanhueza
Carlos andres MedinaCarlos andres Medina
Carlos andres Medina
FSFrancisco Solis-Pomar
Francisco Solis-Pomar
EPEduardo Perez
Eduardo Perez
Nanocomposites and a composite based on poly(butylene adipate-co-terephthalate) (PBAT) were synthesized using commercial copper nanoparticles (Cu-NPs), copper/cuprous oxide nanoparticles (Cu|Cu2O-NPs), and copper sulfate (CuSO4), respectively. The Cu|Cu2O-NPs were synthesized using chemical reduction and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The synthesis of Cu|Cu2O-NPs yielded a mixture of Cu and Cu2O, with metal Cu having a spherical morphology of approximately 40 nm in diameter and Cu2O with a diameter of 150 nm. To prepare the nanocomposites (NCs) and the composite material (MC), the NPs and the CuSO4 salt were incorporated into the PBAT matrix in concentrations of 1, 3, and 5% p/p via an ex situ method. Fourier transform infrared spectroscopy (FTIR), a tensile test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and agar diffusion assays were used for structural, thermomechanical, and antimicrobial characterization. Results showed that the reinforcements did not modify the chemical structure of the PBAT and only slightly increased the percentage of crystallization. The mechanical and thermal properties of the PBAT did not change much with the addition of fillers, except for a slight increase in tensile strength and thermal stability, respectively. The agar diffusion antimicrobial assays showed that the NCs and MCs had good inhibitory responses against the nonresistant strains Enterococcus faecalis, Streptococcus mutans, and Staphylococcus aureus. The MCs based on CuSO4 had the highest biocidal effect, even against the resistant bacteria Acinetobacter baumannii.

27 January 2025 in Applied Sciences
Verified
Journal Article
Open access
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VTVictor Tuninetti
Victor Tuninetti
MHMatías Huentemilla
Matías Huentemilla
ÁGÁlvaro Manuel Gómez Gallegos
Álvaro Manuel Gómez Gallegos
AOAngelo Oñate
Angelo Oñate
BMBrahim Menacer
Brahim Menacer
CMCristobal Montalba
Cristobal Montalba
Water transport pipelines in the mining industry face significant corrosion challenges due to extreme environmental conditions, such as arid climates, temperature fluctuations, and abrasive soils. This study evaluates the effectiveness of three advanced inspection technologies—Guided Wave Ultrasonic Testing (GWUT), Metal Magnetic Memory (MMM), and In-Line Inspection (ILI)—in maintaining pipeline integrity under such conditions. A structured methodology combining diagnostic assessment, technology research, and comparative evaluation was applied, using key performance indicators like detection capability, operational impact, and feasibility. The results show that GWUT effectively identifies surface anomalies and wall thinning over long pipeline sections but faces depth and diameter limitations. MMM excels at detecting early-stage stress and corrosion in inaccessible locations, benefiting from minimal preparation and strong market availability. ILI provides comprehensive internal and external assessments but requires piggable pipelines and operational adjustments, limiting its use in certain systems. A case study of critical aqueducts of mining site water supply illustrates real-world technology selection challenges. The findings underscore the importance of an integrated inspection approach, leveraging the complementary strengths of these technologies to ensure reliable pipeline integrity management. Future research should focus on quantitative performance metrics and cost-effectiveness analyses to optimize inspection strategies for mining infrastructure.

21 December 2023 in Metals
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Journal Article
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Antonio Cañadilla SánchezAntonio Cañadilla Sánchez
Antonio Cañadilla Sánchez
JSJuan Pablo Sanhueza
Juan Pablo Sanhueza
CMCristobal Montalba
Cristobal Montalba
ERElisa María Ruiz-Navas
Elisa María Ruiz-Navas
Aluminum and its alloys are very versatile materials used in a wide range of applications due to the initial characteristics of pure aluminum and the combination of properties obtained from its blend with other elements. Considering that aluminum is the second-most-produced metal after steel, and that its production will increase over time based on the demand to produce products through conventional and additive methodologies, this will lead to an increase in the energy consumed as well as the footprint of carbon generated. It is for this reason that the generation of competitive aluminum alloys must be approached from secondary sources (recycling). To address these environmental issues, in this work, 2070 aluminum alloy (AA2070) samples were manufactured using secondary aluminum powder and compared with the primary aluminum source. The samples were compacted at 700 MPa and sintered at a different range of temperatures between 525 °C and 575 °C. The study includes thermodynamic modeling, microstructure, and mechanical characterization. Microstructure and phases characterization were carried out via scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, respectively, whereas the mechanical characterization comprised relative density evaluation, hardness, and flexion tests. Results were compared with the calculation of phase stability using Thermo-Calc software 2020a. Based on the results obtained, it can be concluded that the secondary AA2070 optimal sintered temperature, where the components raised the highest mechanical properties and effective relative density range, is 575 °C. Furthermore, the recycled alloys have similar relative densities and flexural strengths than the corresponding alloys made from primary aluminum powder.