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Aplicacion de fluorescencia de rayos X en el analisis quimico de residuos de disparos (GSR) en el lugar de los hechos: una revision sistematica
(Universidad Santiago de Cali, 2026-07-21) Roncancio García, John Jairo; Ocampo Chagüendo, Dennis Mauricio(Director)
The study of gunshot residue (GSR) faced limitations regarding the costs and processing times of traditional techniques such as SEM-EDX. Consequently, the viability of implementing X-ray fluorescence spectroscopy (XRF) and its variants (micro-XRF and TXRF), combined with chemometric analysis (PCA), was evaluated as a faster, more cost-effective, and non-destructive screening alternative. The objective was to analyze the capability and scope of XRF to detect, quantify, and discriminate GSR on different substrates and under extreme conditions.
The methodology encompassed three experimental approaches: micro-XRF analysis of samples collected from the hands and face of a shooter; portable XRF evaluation of impacted bovine ribs subsequently calcined at 800 °C; and swab sample collection after discharging firearms, where the extracts were analyzed using TXRF and PCA models.
The results demonstrated that micro-XRF effectively identified lead (Pb) and barium (Ba), although calcium in the skin interfered with antimony (Sb) detection. In the skeletal remains, the inorganic components of GSR survived calcination, showing higher intensity with unjacketed projectiles. Finally, the combination of TXRF and PCA successfully differentiated five calibers and the type of firearm (pistol or revolver), exhibiting limitations only with isolated detonations of a .32 caliber.
It was concluded that XRF constituted a suitable, rapid, and accessible alternative for preliminary GSR analysis. Its non-destructive nature allowed the preservation of evidence severely degraded by fire and facilitated ammunition classification through automated data processing.
Diseño y modelado del proceso de fermentación para la producción de aguardiente artesanal en la Asociación de Cabildos Indígenas del Norte del Cauca ACIN mediante simulación en Aspen Plus y validación experimental.
(Universidad Santiago de Cali, 2026-07-16) Solarte Ossa, Nestor Raul; Tusso Pinzon, Ricardo Andrés(Director); Suárez Osorio, Liseth (Directora)
The artisanal production of sugarcane spirit known as chirrincho represents an ancestral practice of significant cultural, social, and economic importance for the Indigenous communities of northern Cauca, Colombia. However, the lack of control over critical fermentation and distillation variables leads to variability in product quality and limits the reproducibility of the production system. In this context, the present study aimed to experimentally evaluate different thermal fermentation strategies and to develop a process simulation model using Aspen Plus® as a decision-support tool for the analysis and evaluation of operational parameters associated with the distillation column.
The research followed an integrated experimental–computational approach at the artisanal production facility of the Association of Indigenous Councils of Northern Cauca (ACIN). Five fermentation temperature strategies (30 °C, 32 °C, 35 °C, 25–32 °C ramp, and 32–28 °C stepped profile) were evaluated using fifteen fermenters distributed across three replicates per treatment. Process monitoring included apparent soluble solids (°Brix), pH, temperature, and ethanol production. In parallel, physicochemical characterization of the distillate was performed through alcoholic strength, methanol, furfural, mineral composition, and participatory sensory evaluation. Experimental results were subsequently used to build a steady-state Aspen Plus® V14 model employing the NRTL thermodynamic method, an RStoic reactor, and a RadFrac distillation column.
The experimental results showed that fermentation at 35 °C provided the best performance, achieving a maximum ethanol concentration of approximately 79.8 g/L and a relative efficiency of 46.9%. The final distillate contained 38–42% v/v ethanol, meeting the specifications established by the Colombian NTC 410 standard for distilled spirits. Physicochemical analyses indicated methanol and furfural concentrations within the evaluated reference limits. Process simulation identified operational conditions associated with an estimated ethanol recovery of 96.32%, reduced ethanol losses in the bottoms stream, and an improved ethanol–water separation factor compared with the base-case scenario. Mass and energy balance closure errors remained below 0.1%, demonstrating internal consistency of the model under the defined assumptions.
The findings indicate that temperature control is a key variable affecting chirrincho fermentation performance and that the integration of experimental evaluation and process simulation provides a useful framework for analyzing operational scenarios and supporting process improvement. These results contribute technical knowledge for strengthening artisanal production systems while preserving the ancestral knowledge associated with this traditional beverage.
“Revisión sistemática sobre la producción de proteína unicelular a partir de residuos agroindustriales como alternativa sostenible para la alimentación humana”
(Universidad Santiago de Cali, 2026-06-18) Meneses Sotelo, Dasly Mariley; Martinez Garay, Carlos Andrés(Director)
The research conducted a systematic review of single-cell protein production from agro-industrial waste as a sustainable alternative for human consumption. It analyzed microorganisms with the greatest biosynthetic potential, the most efficient substrates, and the fermentation conditions that optimize microbial biomass generation. The methodology was based on the PRISMA, using specialized scientific databases to ensure the quality of the analysis. The results showed that bacteria, yeasts, and fungi have a high capacity to transform organic waste into proteins of excellent nutritional value; they also contribute to reducing the environmental impact associated with waste disposal. It was concluded that these bioprocesses represent a viable biotechnological plan for utilizing agro-industrial by-products and strengthening food security through efficient and ecological sustainability.
Detección electroquímica simultánea de acetaminofén y levofloxacino mediante un electrodo de carbón vítreo modificado con nanopartículas de ferritas Zn₀.₅Co₀.₅Fe₂O₄ sintetizadas con extracto de hinojo.
(Universidad Santiago de Cali, 2026-06-25) Rendón Mera,Katherine; Morales Morales, Jimmy Alexander (Director)
This work presents a strategy for the simultaneous and sensitive detection of acetaminophen and levofloxacin, using an electrode modified with Zn₀.₅Co₀.₅Fe₂O₄ nanoparticles synthesized from natural materials, specifically fennel extract. Acetaminophen, a commonly used analgesic, and levofloxacin, a widely used antibiotic, both accumulate in aqueous media. For the detection of these drugs, a glassy carbon electrode was used, modified with Zn₀.₅Co₀.₅Fe₂O₄ nanoparticles, which helps differentiate the signals of the two substances, allowing for their simultaneous detection. For the simultaneous detection of these drugs, the electrochemical behavior of a mixture of acetaminophen (AC) and levofloxacin (LEV) was evaluated over a pH range of 2 to 10 using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). This demonstrated the suitability of pH 5, as it optimizes the system's analytical response and establishes a representative oxidation environment for the compounds. The electrode was modified with an environmentally friendly suspension of cobalt-zinc ferrite nanoparticles, ultrasonized for 25 min. Seven microliters of the suspension were then deposited onto the electrode surface, followed by drying at 100–150 °C for 8 min. Electrochemical measurements with the modified electrode were carried out using an experimental setup with a 10 mL glass cell, with three compartments to fit the working electrode (GCE), the reference electrode and an auxiliary platinum electrode. This setup was placed on a magnetic stirring plate in such a way as to allow the drugs to be mixed homogeneously with the help of a magnet. These measurements were performed using an AUTOLAB potentiostat/galvanostat (PGSTAT128N, Metrohm Autolab, Herisau, Sweden), operated with the NOVA software, in which cyclic voltammetry (CV) was used to investigate the redox behavior of acetaminophen (AC) and levofloxacin (LE) in the modified electrode, applying a potential sweep between −0.1 V and 1.6 V at a speed of 0.1 V/s and a step of 2.44×10⁻³ V, and differential pulse voltammetry (DPV) was used for quantitative purposes
Multirresistencia bacteriana y reservorios zoonóticos de interés agroindustrial y de salud pública: revisión sistemática.
(Universidad Santiago de Cali, 2026-06-24) Buesaquillo Cuero, Jhon Alverson; Darwich Cedeño, Mohamed Toufic(Director)
Multidrug-resistant bacteria have ceased to be solely a hospital problem, becoming a large-scale global phenomenon affecting animals, the environment, and humans. This systematic research focuses on analyzing how zoonotic reservoirs interact within the agro-industrial sector and their role in the proliferation of critical genes, especially genes like mcr-1. For this reason, a systematic review was conducted following the PRISMA guidelines, analyzing high-impact scientific documents on the existence of multidrug-resistant bacteria in different ecological niches. After analyzing the evidence, Escherichia coli was identified as the primary driver of resistance spread, reaching prevalence levels of 100% in swine and poultry environments. A particularly concerning finding is the stability of the mcr-1 gene within plasmids such as IncI2 and IncX4; their low biological cost allows resistance to persist even after colistin use ceases. Furthermore, the data revealed that transmission is not linear but bidirectional, with infected wastewater potentially colonizing remote ecosystems and harming wildlife. Finally, the fight against antimicrobial resistance cannot be limited to simply banning drugs; it must also require biological containment plans and direct involvement in natural reservoirs. This research highlights that integrated epidemiological monitoring under the One H