Química

Permanent URI for this collection

https://usc.scimago.es/handle/20.500.12421/91

Browse

Now showing 1 - 20 of 43

Análisis estructural y supramolecular del compuesto (e)-3',6'-dihidroxi-2-((pyridina-2-yl metileno) amino) spiro[isoidolina-1,9'-xanteno]-3-ona
(Universidad Santiago de Cali, 2019) Cardona Restrepo, Camila; Fernando D¨vries, Richard
The crystalline structure of the compound (E) -3 ',6'-dihydroxy-2-((pyridine-2-and methylene) amino) spiro [iso-idoline-1,9'-xanthene] -3-one was solved and refined, using single crystal X-ray diffraction data. It was found that the compound crystallized in the triclinic P-1 space group. its unit cell present two molecules per asymmetric unit, which correspond to molecular conformers. Moreover, an analysis to determine the intermolecular interactions from the crystalline system was performed. It was observed that the crystal packing is formed mainly by hydrogen interactions type O-H••• N, and C-H•••O. Finally, the supramolecular interactions of the dimer were quantified using fingerprint plots, obtaining values of 41.4%, 12.9%, 11.1% and 10.4% for interactions type H•••H, C•••H, O•••H, H•••C respectively. The aforementioned diagrams were compared with the obtained for structurally similar molecules; their forms confirmed the differences at the supramolecular level of the compounds analyzed. With this project, it was possible to determine the structural and supramolecular characteristics of the compound. In addition, were acquired the basic concepts related to crystallography and supramolecular chemistry, both at a theoretical and experimental level.
Aplicación de la ecuación de Schrödinger en el estudio del movimiento de moléculas diatómicas
(Universidad Santiago de Cali, 2019) Bueno Barbosa, Douglas Andrés; Parada Valencia, Alexander
Understanding the physiochemical phenomenon at the subatomic level is very important in order to know the behaviour of the matter these energy scales. It is necessary to use the Schrödinger equation in the order to describe chemical and physically the molecules. Throughout of the development of this work, we addressed the study of the Schrödinger equation and applications in the movement of diatomic molecules. The interaction potential is described by this equation, as well as the translational, rotational and vibrational energies of each molecule. Likewise, the Hamiltonian is studied in a general way, and particularly for the hydrogen molecule. We learned the main knowledge relating with Quantum Chemical and after that we focus in the study of some diatomic molecules no studied in the literature until now. Then, a phenomenological study was carried out for the BrCl molecule.
Aplicación de la espectroscopia de infrarrojo cercano (NIRS) en productos cárnicos
(Universidad Santiago de Cali, 2024) Rosero Martínez, José Miguel; Castro, Sandra Patricia (Director)
An approximation is made to near infrared spectroscopy (NIRS) as a tool for evaluating the quality and authenticity of meat products. Given the growing demand for organic meat products and the need to guarantee their integrity, NIRS stands out as an effective alternative to traditional methods. The methodology employed included literature review, data analysis and method comparison, highlighting the importance of developing more robust calibration and standardization techniques. Quality parameters that NIRS can assess, such as moisture, fat, protein, color and pH, were identified, demonstrating its ability to provide rapid and non-destructive results. Comparison between NIRS and traditional techniques such as proximate analysis revealed that NIRS offers significant advantages in terms of speed and reduced need for sample preparation. However, limitations have been identified, including the need for specific calibrations for each type of meat and the dependence on the quality of the equipment used. Recommendations include advancing the development of calibration techniques and exploring the integration of NIRS technology in real-time computing environments
Aplicación del diseño de mezclas en la formulación de sidra de manzana
(2020) RAMÍREZ NARANJO; NATHALIA, SINISTERRA AMÚ; DIANA; Ramirez Navas; Juan Sebastian
Cider is a drink with very marked characteristics with respect to other spirits; It has abundant carbon dioxide, but produces less foam than a regular beer, acquires shades of yellow in transparent and bright appearance. (Drilleau, 2005). Cider. 2. The objective of this research was to evaluate the ratio of cider mixtures from three varieties of apple (Malus Domestica): Gala, Golden and Green.
“Aplicación del diseño de mezclas en la formulación de sidra de manzana (malus domestica)”
(Universidad Santiago de Cali, 2020) Ramírez Naranjo, Nathalia; Sinisterra Amú, Diana; Ramírez Navas, Juan Sebastián
Cider is a drink with very marked characteristics with respect to other spirits; It has abundant carbon dioxide, but produces less foam than a regular beer, acquires shades of yellow in transparent and bright appearance. (Drilleau, 2005). Cider. 2. The objective of this research was to evaluate the ratio of cider mixtures from three varieties of apple (Malus Domestica): Gala, Golden and Green. This mixing design consisted of applying a planning and analysis methodology which could ensure that we obtain the knowledge and solutions. The adoption of this methodology aims to assess the influence of each component of the formulation on the selected response varieties. For this purpose, different physicochemical tests were performed on each mixture obtained: (pH, Density, Volatile Acidity, alcoholic Strength and Sugar Percentage) and from which the expected results were obtained with an average of pH between 3.6 - 3.8; Density between 0.99-1.02 g/mL; Volatile Acidity between 0.04 -0.09 g/L; Alcohol content between 0.73 - 2.4 %V; Microbiological: (Count of aerobic bacteria and mesophylls, mold count, yeast count and total coliforms) whose result of each test was <10 UCF/mL and Sensory Analysis in which preference was found for the sample called B, corresponding to the mixture 0,1/2,1/2 being this the mixture between green apple and gallium apple. The results obtained in each test were expected indicating that the drink does meet the requirements established by the Colombian technical standard NTC 222 and NTC 708, concerning alcoholic beverages and their general definitions, alcoholic beverages (Fruit wines) respectively
Calificación de un dispositivo de inmersión para así realizar recubrimientos de TiO2/Hidroxiapatita sobre superficies metálicas
(Universidad Santiago de Cali, 2019) Martínez Bellaiza, Daniela; Morales Morales, Jimmy Alexander; Castillo Ayala, Jorge Enrique
El método de inmersión o “Dip-Coating” es utilizado para la obtención de películas delgadas sobre diferentes superficies y con un amplio rango de aplicación; este consiste en la inmersión y posterior extracción de un sustrato dentro de una solución precursora para la formación de la película. En este trabajo se realizó la calificación de un dispositivo de inmersión de bajo costo elaborado en la Universidad Santiago de Cali y se ejecutaron recubrimientos sobre sustratos de acero inoxidable con TiO2/Hidroxiapatita por la técnica de química húmeda. Para la calificación se evaluaron parámetros de velocidad y tiempo de inmersión, abordando la calificación de instalación, desempeño y diseño (IQ, PQ y QD respectivamente); la síntesis de Hidroxiapatita se realizó por precipitación controlada y se analizaron las muestras secas por IR/ATR y TGA-DSC obteniendo unos picos característicos del compuesto y un buen comportamiento térmico, además se analizaron los revestimientos realizados utilizando técnicas espectroscópicas obteniendo los depósitos esperados en los sustratos y obteniendo una relación de Ca/P de 1,57.
Caracterización fisicoquímica de tres aceites de cocina usados para freír diferentes alimentos y los respectivos biodiesel obtenidos por transesterificación en la ciudad santiago de cali, colombia.
(Universidad Santiago de Cali, 2024) Guerra Cuaran, Lina Alexandra; Bonilla Ramírez, Luis Fernando; Tusso, Ricardo Andrés; Zambrano Salgado, Yesid Fabián (Directores)
The increase in global energy demand and the environmental concerns related to the use of fossil fuels, creates the need to find more sustainable alternatives, highlighting the relevance of biofuels to reduce dependence on oil. This study focuses on obtaining three types of biodiesel from Used Cooking Oils (UCO), from the frying of empanadas, fritters, breaded chicken and a new palm oil biodiesel used as a reference. Physicochemical tests were carried out to characterize the oils and biodiesel obtained to evaluate their potential as biofuel. Their yield was determined and 93.1% fritters, 87.5% empanadas and 90.6% breaded chicken were obtained. Based on the results of the characterization and their yield, it was determined that the biodiesel from the breaded chicken ACU has the greatest potential as biofuel and the biodiesel from the breaded chicken ACU proved to be the least suitable for such use.
Caracterización fisicoquímica funcional del Almidón extraído de la papa china (Colocasia Esculenta) cultivada en el pacífico colombiano
(Universidad Santiago de Cali, 2019) Hurtado Herrera, Janer Guillermo; Castillo Ayala, Jorge Enrique
The evaluation of the physicochemical and functional properties of the starch extracted from the Chinese potato tubers (Colocasia esculenta) from the municipality of Timbiquí and López de micay – Cauca was carried out. The granules had particle size around (3.5-7.8 µm in diameter for sample 1 and 3.5-7.0 µm in diameter for sample 2); a high content of % amylose (67.6 and 70.7 respectively for M1 and M2) was found compared to other botanical sources, through the colorimetric method recommended by ISO 6647. The gelatinization temperatures were (78, 6 and 81.9 ° C, respectively) by heating a solution of the starch until a stable paste formed for a few seconds. The samples showed low water solubility (0.13 M1 and 0.23 M2 g / 100 mL) and a high water retention capacity (280.3 and 391.7% at 60 ° C) compared to 226% of the cassava and 162.8% for sago: which makes it a good quality starch. The gel pastes when subjected to a % processing of light at 650 nm in a Thermo Evo 201 UV spectrophotometer was (3.4 and 4.1%) respectively. Comparing these characteristics found in this tuber with other sources of starch commonly used in the industry, it is concluded that it can be used as a promising alternative in the food industry; In addition to having a high amylose content, it is a resistant starch, providing physiological health benefits.
Caracterización fisicoquímica y funcional del almidón extraído de la papa china (Colocasia esculenta) cultivada en el pacífico colombiano
(Universidad Santiago de Cali, 2020) Hurtado Herrera, Janer Guillermo; Castillo Ayala, Jorge Enrique
The evaluation of the physicochemical and functional properties of the starch extracted from the Chinese potato tubers (Colocasia esculenta) from the municipality of Timbiquí and López de micay – Cauca was carried out. The granules had particle size around (3.5-7.8 μm in diameter for sample 1 and 3.5-7.0 μm in diameter for sample 2); a high content of % amylose (67.6 and 70.7 respectively for M1 and M2) was found compared to other botanical sources, through the colorimetric method recommended by ISO 6647. The gelatinization temperatures were (78, 6 and 81.9 ° C, respectively) by heating a solution of the starch until a stable paste formed for a few seconds. The samples showed low water solubility (0.13 M1 and 0.23 M2 g / 100 mL) and a high water retention capacity (280.3 and 391.7% at 60 ° C) compared to 226% of the cassava and 162.8% for sago: which makes it a good quality starch. The gel pastes when subjected to a % processing of light at 650 nm in a Thermo Evo 201 UV spectrophotometer was (3.4 and 4.1%) respectively. Comparing these characteristics found in this tuber with other sources of starch commonly used in the industry, it is concluded that it can be used as a promising alternative in the food industry; In addition to having a high amylose content, it is a resistant starch, providing physiological health benefits
Caracterización térmica y espectroscópica de sulfato de calcio dihidratado y sulfato de calcio hemihidratado
(Universidad Santiago de Cali, 2024) Correa Castaño, Leonel; Gutiérrez Moreno, Nini Johanna; Castillo Gómez, Duván Fernando (Directores)
The main objective of the present work was the thermal and spectroscopic characterization of calcium sulfate dihydrate and hemihydrate. Differential scanning calorimetry (DSC) and thermogravimetry (TGA) thermal analysis techniques were applied, finding characteristic peaks at 102 °C for the hemihydrate, 52.5 and 126.7 °C for the dihydrate. TGA showed a weight loss of 1.5% at 38.27 °C, 3% at 73.14 °C and 8.5% at 110 °C for the hemihydrate, the dihydrate showed weight losses of 17% at 56 °C, 31.6% at 110 ° C and 41.4% at 130 °C. Analysis by FT-IR revealed absorption bands between 3700 and 3500 cm-1 typical of the water molecules present and bands between 1200 and 900 cm-1 characteristic of the S=O double bond. The 20.72°, 23.38° and 29.14° for the dihydrate form. The determination of heavy metals by atomic absorption showed concentrations below 60 ppm in Na, Fe, Pb, As and Cd. The micrographs taken by SEM revealed the morphology of the crystals for the study compounds, exposing a varied number of sizes. It was found that the product has high purity, without the presence of anhydrites and low concentrations of metals such as Na, Fe, Pb, As and Cd.
“Caracterización y determinación de polifenoles, flavonoides y actividad antioxidante por diferentes tipos de extracción en catharanthus roseus l. g don”.
(Universidad Santiago de Cali, 2020) Sánchez Marín, Mónica María; López Parra, Lizbeth Lorena
Correlación instrumental y sensorial de la calidad de una muestra de yogurt de la empresa fructilacteos
(Universidad Santiago de Cali, 2019) Giraldo, María, Camila Erazo; Ramírez Navas, Juan Sebastián
Greek yogurt samples from the company fructilácteos of campo were sensorially characterized by a semi-trained panel. Likewise, a study of the physical-chemical parameters of the same was carried out. The objective was to correlate the sensory parameters with the instrumental ones (viscosity, syneresis, pH, acidity, soluble and total solids) to identify the instrumental parameters that approximate the sensations experienced when consuming fructilácteos Greek yogurt (YGF). On the sensory side of the panelists, there was a preference for YGF for its attribute of creaminess and acidity, while on the part of the consumer a preference of 58% was observed by the YGC, mostly male consumers, however in the instrumental parameters it is revealed that most of them enter the established limit, minus the parameter of viscosity, which was 1.02.
Cuantificación por HPLC de Trans-resveratrol en la uva Isabella (vitis labrusca) cultivadas en la Unión-Valle del Cauca
(Universidad Santiago de Cali, 2019) Ospina Ramírez, Stephanie; Castillo Ayala, Jorge Enrique
The Isabella grape (Vitis labrusca) is a variety that has been optimally adapted to the climatic conditions of La Unión-Valle del Cauca, and has had good acceptance in local markets. Currently the grape is consumed fresh and its phenolic content is unknown. According to epidemiological studies, the presence of bioactive compounds with antioxidant capacity such as trans-resveratrol, can exert a protective effect against some diseases such as cancer and cardiovascular disorders. For this reason, with this work the quantification of the trans-resveratrol present in the epicarp of the Isabella grape (Vitis labrusca) grown in La Unión-Valle del Cauca is performed, using high efficiency liquid chromatography (HPLC) with ultraviolet detector. It will ensure that the method to follow complies with the evaluation parameters (linearity, precision and accuracy). It is also intended to contribute to a methodological proposal for the extraction (liquid-liquid with acidified methanol) and purification of trans-resveratrol.
Degradación de Ampicilina, Catecol y el colorante naranja II, a partir de residuos de CdS obtenidos de prácticas convencionales de química inorgánica
(Universidad Santiago de Cali, 2019) Vidal Ruíz, Victor Alfonso; Avila Torres, Yenny
The elimination of orange dye, catechol and ampicillin (products present in waste from practical work of organic chemistry and biochemistry), was carried out with cadmium sulfide (CdS). This inorganic material was obtained from of residues of acid- base Pearson's practices in the laboratories of inorganic and analytical chemistry. Cadmium sulfide is a semiconductor with a GAP 2.4-2.6 ; which allows its use as a photocatalyst in the visible region and enhances its application in the degradation of organic matter. An important source of this type of materials are the conventional practices at the laboratory level, where it is possible to obtain residues such as PbS and CdS; which are generally underutilized. In this article, the impure CdS residue was purified and characterized as was reported, previously. Subsequently, organic labs and has obtained the best parameters at pH neutral for the elimination of orange II. This behavior was compared with the transformation of catechol and ampicillin as neutral and zwitterion molecules. H2O2, KI and acetonitrile as solvent, were added in to order to evaluate synergistic effects and establish the role of the semiconductor, (huecos) h+ and OH-. This work is a contribution to the reuse of waste in teaching laboratories, which promote the recirculation water contaminated with this type of organic compounds and allows for the student to design experimental protocols that allow him to use two types of organic and inorganic waste.
Desarrollo de dos antiespumantes en Disproquin S.A.S con aplicación en el proceso de producción de papel
(Universidad Santiago de Cali, 2019) Rojas Daza, Andrés Felipe; Floréz López, Edwin
In the paper industry the generation of foam is an important factor because it causes the paper to get porous structures affecting its quality. On the other hand, antifoam products are very effective in suppressing the foam generated in different processes. For this reason, two hydrocarbon and silicone-based antifoams were developed. For their characterization, physicochemical parameters such as pH, percentage of total solids, viscosity, particle size and density were determined. Fourier Transform Infrared Spectroscopy (FTIR), one of the components of the hydrocarbon-based antifoam, was also used. An experimental design was used to compare the efficiency of the hydrocarbon-based antifoam with a commercial antifoam followed by an efficiency study of the silicone-based antifoam. Finally, it was demonstrated that the hydrocarbon-based antifoam is more efficient as an antifoam and defoamer than the commercial product. Consequently, the silicone-based antifoam compound showed high efficiency at a temperature between 70 and 90 °C and a pH between 8 and 11. All these results show that these products could be used in different types of industries
Desarrollo de una técnica miniaturizada para la determinación de nitrosaminas en productos cárnicos mediante hs-spme-gc/ms
(Universidad Santiago de Cali, 2024) Gamboa Castillo, Miller Arbey; Ríos Acebedo, Jhon Jairo
Several studies have shown that the consumption of processed meat products is strongly linked to cancer associated with nitrosamines formed by the addition of nitrate or nitrite salts and certain amines. In this work, a method was developed for the determination of volatilenitrosamines in commercial sausages using headspace sampling by solid-phase microextraction and gas chromatography coupled to a mass spectrometer (HS-SPME-GC-MS). Two fused silica fibers were evaluated, one coated with polydimethylsiloxane (PDMS) and the other with carboxen/polydimethylsiloxane (CAR/PDMS). A fractional factorial design was employed to evaluate the influence of equilibrium time, ionic strength, extraction time, extraction temperature, and the addition of methanol on the extraction of Nnitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-butylamine (NDBA), and N-nitrosopiperidine (NPIP) in sausages. The method was validated and applied for the determination of nitrosamines in sausages, with linear ranges between 0-50 µg/L. The coefficients of determination for the calibration curves ranged from 0.9906 to 0.9976; the limits of quantification were between 0.254 and 0.389 µg/L. The precision and accuracy of the method were within the ranges of 2.7-7.3% and 70.286.4%, respectively. The implemented method proved to be simple, rapid, and exhibited adequate accuracy, sensitivity, and precision.
Determinación de la Biodisponibilidad in vitro de hierro en diferentes matrices alimentarias elaboradas a partir de harinas fortificadas comerciales
(Universidad Santiago de Cali, 2019) Guzmán Aristizabal, Luisa María; Usuriaga Moreno, María Camila; Ramírez Navas, Juan Sebastian
Iron (Fe) deficiency has been recognized with the World Health Organization as a public health problem, in countries such as Colombia. It affects a large part of the inhabitants, especially children and women in gestation. In order to counteract the consequences generated by this population, the lack of this mineral establishes the need to use Iron Fortification. The aim of this work was to evaluate the effect of temperature on the iron diazability of three homemade preparations, in which commercial flours fortified with iron were used. The percentage dialysotity of Iron (Fe) was taken as an indicator of the bioavailability of said ore. The determination was made using the in vitro method, which includes an enzymatic digestion that simulates the physiological process under controlled pH conditions and subsequent quantification by atomic absorption spectroscopy. For each of the samples an estimated percentage between 4 and 5% was obtained which are according to the literature in that they do not exceed 10% absorption of non-hemine iron from food.
Diseño de un sistema de gestión ambiental para la empresa Análisis Ambiental S.A.S., basado en la norma NTC 14001: 2015
(Universidad Santiago de Cali, 2019) Mosquera Mosquera, Gloria Stephanía; Angulo Piñeros, Nathalia; Garzón García, Guillermo; Robles Pardo, Edilberto
La empresa ANALISIS AMBIENTAL S.A.S. presta servicios de Ingeniería Ambiental y Sanitaria que incluyen asesorías en plantas de tratamiento de aguas, monitoreos en agua, aire y suelos; como también servicios de análisis de Laboratorio fisicoquímicos y microbiológicos. Estos servicios generan impactos sobre el medio ambiente, y siendo conscientes de ello, se ha diseñado un Sistema de Gestión Ambiental basado en la Norma NTC - ISO 14001 de 2015 para conocer su naturaleza, y de esa forma mitigar y/o controlarlos de manera efectiva.
Diseño e implementación de un sistema de gestión de calidad en el laboratorio cosmético khemeia green s.a.s basado en la norma NTC ISO 9001:2015
(Universidad Santiago de Cali, 2020) Chaves Hernández, Angie Liliana; Garzón García, Guillermo
The purpose of this degree work was to implement a Quality Management system in a cosmetics laboratory, in order to increase the quality of its services and the level of competitiveness in the market, with the main objective being the high recognition and preference of its services by consumers, therefore this work aims to develop an implementation plan for the Quality Management System supported by ISO / NTC 9001; 2015, which allows the Khemeia Green S.A.S laboratory to integrate its activities with a risk-based approach and continuous improvement of each of its tests, generating greater customer satisfaction. It began by making a diagnosis of the state in which the quality management system was, defining the processes that were documented and which were not, in order to structure a work plan for the development and implementation of each of the numerals present in the standard, continuously finding the improvement in the process; Once the diagnosis was completed, the requirements of ISO / NTC 9001 were condensed; 2015, and the results obtained were the sensitization of the personnel, the development of different documentary procedures, organizational structuring (organizational chart), construction of the laboratory quality policy and other documentation required with the accompaniment of senior management; The relationship that this has with the quality of the service and the product, and in an increase in productivity, was announced. In addition, the improvement of each of the laboratory areas, equipment, products, as well as the recognition and reduction of customer complaints was achieved.
Diseño, implementación y certificación del sistema de gestión de la calidad bajo los requisitos de la norma ntc-iso 9001:2015 para el laboratorio de ciencias básicas de la universidad Santiago de Cali
(Universidad Santiago de Cali, 2020) Pineda Quintero, Cindy Alejandra
The Laboratory of Basic Sciences, as part of its strategic development, decides to initiate the implementation and documentation of a Quality Management System under the requirements of the International Standard ISO 9001: 2015, with the objective of guaranteeing the continuous improvement of its processes, Increase customer satisfaction and be competitively located in the local and regional market by offering a timely service and ensuring the validity and traceability of the reported data. To establish a work route aimed at achieving certification, a work plan was defined that began with the diagnosis of the Laboratory in terms of compliance with standard requirements, for this, the entire existing document base was compiled. With the information obtained, the methodology based on the PHVA cycle was designed, which resulted in the study of the context of the Laboratory, the identification of the needs and expectations of the interested parties, the definition of the process quality objectives, the scope , the identification, evaluation, analysis and map of risks associated with the process, all this to finally structure the quality manual and facilitate the revision of the Quality Management System implemented, first by an internal quality audit that delivered a favorable concept for the presentation to external quality audit, which certified compliance with the requirements of the audited standard, ISO 9001: 2015, and granted the extension of the scope for the Subsystem to which the Basic Sciences Laboratory belongs.

Browse

Browsing Química by Title

Results Per Page

Sort Options