2024-03-28T16:14:00Z
https://revistas.javeriana.edu.co/index.php/iyu/oai
oai:ojs.revistas-javeriana.repositoriodigital.com:article/10213
2020-08-21T18:53:34Z
iyu:B%26CE
driver
"151207 2015 eng "
2011-2769
0123-2126
dc
Anthocyanin production evaluation using plant cell cultures. growth and viability analysis at different process conditions
García-Velásquez, Carlos Andrés
Universidad Nacional de Colombia
Cardona-Álzate, Carlos Ariel
Universidad Nacional de Colombia
The comparison between the structured and unstructured models was performed in order to determine the mathematical approach that best fit the biological synthesis of anthocyanins from plant cell cultures. A structured model was used for the production of secondary metabolites using cell cultures of strawberry (Fragaria ananassa) taking into account the cell viability of pigmented and non-pigmented cells. Moreover, growth and anthocyanin production of cell suspensions of grape (Vitis vinifera) were evaluated by an unstructured model. Both models adequately described the growth of plant cells and substrate uptake. However, anthocyanin production is intrinsically related to cell growth, especially degradation thereof; therefore the structured model was selected to describe the production of this secondary metabolite.
Pontificia Universidad Javeriana
2015-12-07 00:00:00
application/pdf
application/vnd.openxmlformats-officedocument.wordprocessingml.document
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/10213
Ingenieria y Universidad; Vol. 20 No. 1 (2016): January-June
eng
Copyright (c) 2015
oai:ojs.revistas-javeriana.repositoriodigital.com:article/10884
2020-08-21T17:56:13Z
iyu:B%26CE
driver
"160620 2016 eng "
2011-2769
0123-2126
dc
Process simulation-based improvements to maximize naphtha production in an existing gas processing plan
Mesa-Gómez, Adriana
Universidad de la Sabana
Valero-Valdivieso, Manuel
Universidad de la Sabana
Figueredo-Medina, Manuel
Universidad de la Sabana http://orcid.org/0000-0001-9644-8034
This study estimates the parameters for the proper operation of each one of the process stages (compression, cooling, and separation) in an existing gas processing plant, which processes 1.5 million standard cubic feet per day (MMSCFD). The study also proposes changes in some existing operational equipment to maximize the production of naphtha, which translates into an improved efficiency in each analyzed stage and an improved production rate of fuel gas, liquefied petroleum gas (LPG) and naphtha, which are current products of the plant. First, the gas plant was simulated using the Aspen HYSYS® V7.3 software with the current operational plant conditions and the measured properties of the fluids (gas chromatography for input gas, fuel gas, and LPG). Subsequently, unidimensional searches were performed via sensitivity analyses of the key stages of the process to obtain suitable parameters for improving naphtha production. This resulted in a maximum naphtha recovery rate of 99.13% (which is an improvement over the current recovery rate of 82.79%) and an increase in naphtha quality of 20.85%. The study allowed to have a sensibility analysis for nafta recovery, which provides a tool for decision-making and establishes a basis for analyzing other plants
Pontificia Universidad Javeriana
2016-06-20 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/10884
Ingenieria y Universidad; Vol. 20 No. 2 (2016): July-December
eng
Copyright (c) 2016 Adriana María Mesa Gómez, Manuel Fernando Valero Valdivieso
oai:ojs.revistas-javeriana.repositoriodigital.com:article/11283
2020-08-22T00:34:18Z
iyu:B%26CE
driver
"151207 2015 eng "
2011-2769
0123-2126
dc
Theories of mechanically induced tissue differentiation and adaptation in the musculoskeletal system
Suárez, Daniel Ricardo
Pontificia Universidad Javeriana
It is well known that the mechanical environment affects biological tissues. The importance of theories and models that aim at explaining the role of the mechanical stimuli in process such as differentiation and adaptation of tissues is highlighted because if those theories can explain the tissue’s response to mechanical loading and to its environment, it becomes possible to predict the consequences of mechanical stimuli on growth, adaptation and ageing of tissues. This review aims to present an overview of the various theories and models on tissue differentiation and adaptation of tissues and their mathematical implementation. Although current models are numerically well defined and are able to resemble the tissue differentiation and adaptation processes, they are limited by (1) the fact that some of their input parameters are likely to be site- and species-dependent, and (2) their verification is done by data that may make the model results redundant. However, some theories do have predictive power despite the limitations of generalization. It seems to be a matter of time until new experiments and models appear with predictive power and where rigorous verification can be performed.
Pontificia Universidad Javeriana
2015-12-07 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/11283
Ingenieria y Universidad; Vol. 20 No. 1 (2016): January-June
eng
Copyright (c) 2015
oai:ojs.revistas-javeriana.repositoriodigital.com:article/15673
2020-09-16T20:08:54Z
iyu:B%26CE
driver
"170612 2017 eng "
2011-2769
0123-2126
dc
Production and characterization of the mechanical and thermal properties of expanded polystyrene with recycled material
Barrera-Castro, Gina Paola
Universidad Nacional de Colombia
Ocampo-Carmona, Luz Marina
Universidad Nacional de Colombia
Olaya-Florez, John Jairo
Universidad Nacional
Introduction: Three materials were made with mixtures of virgin expanded polystyrene (EPS) grade S3 and recycled material from multipurpose EPS packaging. Thee latter was subjected to washing and grinding in a blade mill, with percentages by weight of recycled material 10, 15, and 20%. Methodology: The mechanical properties of these materials were evaluated by testing compressive strength and flexural, impact, and thermal properties using the techniques of differential scanning calorimetry and thermogravimetry. Hot plate and steady state temperatura profiles in a non-steady state were simulated with Octave 3.6.4. Results: Thee results obtained for the three mixtures showed little variation in the properties of compression, impact, glass transition, and termal diffusivity with respect to the reference material. The regularity of the decline in mass loss as a function of temperature evidences homogeneity in the samples. e flexural strength decreased the maximum failure load compared to the virgin material, and the thermal conductivity exceeded 0.06W/mK, reducing their insulating capacity. Conclusion: Theese materials can be industrially manufactured in order to produce packaging, caissons, and spheres, among other things.
Pontificia Universidad Javeriana
2017-06-12 00:00:00
application/pdf
application/vnd.openxmlformats-officedocument.wordprocessingml.document
https://revistas.javeriana.edu.co/index.php/iyu/article/view/177
Ingenieria y Universidad; Vol. 21 No. 2 (2017): July-December
eng
Copyright (c) 2017 Gina Paola Barrera Castro, John Jairo Olaya Florez, Luz Marina Ocampo Carmona
oai:ojs.revistas-javeriana.repositoriodigital.com:article/16865
2020-08-14T03:44:33Z
iyu:B%26CE
driver
"161214 2016 eng "
2011-2769
0123-2126
dc
Thermal and Permeability Properties of Metal Aluminum Foams for Functional Applications
Fernández-Morales, Patricia
Universidad Pontificia Bolivariana http://orcid.org/0000-0003-2344-1418
Cano-Montoya, Carlos Alberto
Endicontrol
Pérez-Mesa, Jesús Alberto
Universidad EAFIT
Navacerrada, María Ángeles
Universidad Politécnica de Madrid
Objetivo: se hicieron pruebas de transferencia térmica y de caída de presión para determinar los coeficientes de permeabilidad y de conductividad térmica de espumas metálicas de aluminio fabricadas mediante el proceso IPS (Infiltración de Preformas Solubles). Método: para ambas pruebas, se utilizaron muestras de espumas metálicas con 50mm de diámetro y 20mm de espesor, con tamaños de poro de 0.5, 1.0 y 2.0mm y una densidad relativa de 0.34. Para la realización de las pruebas de caída de presión, se realizó una adaptación de un sistema de flujo de fluidos y, los valores de permeabilidad se calcularon utilizando la ley de Darcy. Por otra parte, para obtener los coeficientes de conductividad se utilizó el ensayo de la caja térmica y la ley de Fourier. Resultados: se encontró que hay una influencia importante del tamaño de los poros en los valores de permeabilidad y de conductividad térmica obtenidos. Por último, los resultados se compararon con los obtenidos por otros investigadores, determinando que estos son muy consistentes con los encontrados en el presente trabajo. Conclusiones: nuestro interés es mejorar el conocimiento sobre las espumas metálicas y en este sentido, proponer la posibilidad de su uso en aplicaciones que involucran flujo de fluidos y transferencia de calor.
Pontificia Universidad Javeriana
2016-12-14 00:00:00
application/pdf
application/vnd.openxmlformats-officedocument.wordprocessingml.document
https://revistas.javeriana.edu.co/index.php/iyu/article/view/16865
Ingenieria y Universidad; Vol. 21 No. 1 (2017): January-June
eng
Copyright (c) 2016 Patricia Fernández Morales, Carlos Alberto Cano-Montoya, Jesús Alberto Pérez-Mesa, María Ángeles Navacerrada
oai:ojs.revistas-javeriana.repositoriodigital.com:article/17575
2020-08-15T17:10:12Z
iyu:B%26CE
driver
"171214 2017 eng "
2011-2769
0123-2126
dc
Optimizing the incorporation of aloe vera in yacon (smallanthus sonchifolius poepp. & endl.) Through vacuum impregnation using response surface
Oblitas-Cruz, Jimy
Universidad Privada del Norte http://www.upn.edu.pe/ http://orcid.org/0000-0001-7652-6672
Rojas-Gutierrez, Erika
Centro de Investigaciones e Innovaciones de la Agroindustria Peruana
Objectives: The aim of this research was to optimize the parameters for the vacuum impregnation of aloe vera into dried yacon (Smallanthus sonchifolius Poepp. & Endl.) flakes. Methodology: A surface response methodology was use to evaluate the product optimization. Matrix engineering, using a vacuum impregnation technique, was employed to incorporate components with physiological activity into the pores present in the yacon flakes. An orange pulp yacon was used as the starting material and Aloe Gold Seal-Natural 200X (AGS) was used for the impregnate solution. A solution of 15 g/100 ml Natural aloe 200X Gold Seal-yacon was used to impregnate yacon samples measuring 40 mm in diameter and 5 mm thick. The results show an average impregnation of 0.0721 m3 of solution/ m3 fresh fruit and an effective porosity of 18.97%; the amount of aloe vera incorporated in the food matrix was between 22.5 and 54.6 mg/100g sample. Optimized parameters were identified as 451.777 mbar and 22.0711 minutes. Results: From the results, it is concluded that yacon is an excellent raw material for vacuum impregnation of aloe vera.
Pontificia Universidad Javeriana
2017-12-14 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/17575
Ingenieria y Universidad; Vol. 22 No. 1 (2018): January-June
eng
Copyright (c) 2017 Jimy Frank Oblitas Cruz, Erika Liliana Rojas Gutierrez
oai:ojs.revistas-javeriana.repositoriodigital.com:article/18515
2020-09-16T20:09:37Z
iyu:B%26CE
driver
"180809 2018 eng "
2011-2769
0123-2126
dc
Technical evaluation for the proposal of a different cricondentherm limit for the Caribbean coast within Colombian gas quality regulations
Navarro-Ochoa, Ingrid
Universidad de La Sabana
Figueredo-Medina, Manuel
Universidad de La Sabana http://orcid.org/0000-0001-9644-8034
Introduction: The cricondentherm is the highest temperature above which a liquid cannot be formed, regardless of the pressure. According to the Colombian natural gas transmission regulations, this temperature should not exceed 7.2°C. Although this restriction is currently applied over the whole country, it is possible to propose a different limit on the cricondentherm for the Colombian Caribbean coast. Methods: In this document, the current hydrocarbon dew point (HCDP) limits for gas transport pipelines in several countries worldwide are analyzed, the weather conditions on the Colombian Caribbean coast are reviewed, and a thermodynamic and hydraulic study is developed, taking into account the composition of the gas (before any treatment) from three fields on the Caribbean coast, the elevation profile of one of the gas pipelines on the Caribbean coast, and the influence of the weather conditions on the behavior of gas in the pipeline. Results: Some countries define their HCDP values depending on the region through which the gas is transported. Simulations of the chosen gas pipeline with lean gases without any treatment at the worst ambient conditions of the Colombian Caribbean coast show that there is a slight liquid condensation at 21°C, indicating a gap with the current regulations (7.2°C) in which an additional maximum cricondentherm can be proposed for the Colombian Caribbean coast. Conclusions: From this work, it is concluded that a new cricondentherm for warm climates in Colombia, within the transmission regulations, should be between 10 and 12.6°C. This proposal is based on the results obtained in simulations and the acknowledgment that some of the Colombian gas pipelines operate only in warm regions of the country.
Pontificia Universidad Javeriana
2018-08-09 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/18515
Ingenieria y Universidad; Vol. 22 No. 2 (2018): July - December
eng
Copyright (c) 2018 Manuel Alfredo Figueredo Medina, Ingrid Navarro Ochoa
oai:ojs.revistas-javeriana.repositoriodigital.com:article/19042
2020-09-16T20:09:37Z
iyu:B%26CE
driver
"180809 2018 eng "
2011-2769
0123-2126
dc
Niobium carbide coatings produced on tool steels via thermo-reactive diffusion
Orjuela-Guerrero, Fredy Alejandro
Universidad Nacional de Colombia
Olaya-Florez, John Jairo
Universidad Nacional de Colombia
Alfonso-Orjuela, José Edgar
Universidad Nacional de Colombia
Objective: In this work, niobium carbide (NbC) coatings were deposited on substrates of the tool steels AISI H13 and AISI D2 using thermo-reactive deposition/diffusion (TRD) in order to analyze their behavior against corrosion in a saline environment. Materials and methods: The niobium carbides were obtained using salt baths composed of borax pentahydrate, aluminum and ferroniobium. This mixture was heated at 1050 °C for 4 hours. The chemical composition was determined by X-ray fluorescence (XRF). The coatings were morphologically characterized using scanning electron microscopy (SEM), the crystal structure was analyzed using X-ray diffraction (XRD), and the electrochemical behavior was studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Results and discussion: The XRF analysis indicated that the coatings contained 87.476 wt% Nb and 51.943 wt% Nb for the D2-substrate and the H13-substrate, respectively. The SEM images revealed that the morphology of the surface of the coatings was homogeneous. The XRD analysis established that the coatings were polycrystalline, and the electrochemical tests established that the corrosion resistance increased slightly in the covered substrates with respect to the uncoated steels, with the best results being obtained in the layers of niobium carbide deposited on AISI D2 steel. Conclusions: The analysis of corrosion resistance revealed that the coatings prepared on D2 steel have a higher corrosion resistance because they have fewer surface imperfections, which causes the coating to exhibit a dielectric behavior.
Pontificia Universidad Javeriana
2018-08-09 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/19042
Ingenieria y Universidad; Vol. 22 No. 2 (2018): July - December
eng
Copyright (c) 2018 Alejandro Orjuela Guerrero, Jairo Olaya Florez, Edgar Alfonso Orjuela
oai:ojs.revistas-javeriana.repositoriodigital.com:article/20574
2020-09-16T20:09:37Z
iyu:B%26CE
driver
"180809 2018 eng "
2011-2769
0123-2126
dc
Surface treatments of ti-alloy based bone implant manufactured by electrical discharge machining
Qosim, Nanang
Universitas Indonesia http://orcid.org/0000-0002-1910-9423
Supriadi, Sugeng
Universitas Indonesia
Shamsuddin-Saragih, Agung
Universitas Indonesia
Whulanza, Yudan
Universitas Indonesia
Objective: This research aims to observe the extent to which several surface treatment techniques increase the surface roughness of titanium alloy implants which was manufactured via electrical discharge machining (EDM). The effects of these techniques were also observed to decrease the Cu content on the implant surface. Materials and Methods: In this research, ultrasonic cleaning, rotary tumbler polishing, and brushing were employed as techniques to increase the roughness of a titanium implant which was manufactured via EDM, to the moderately rough category, and to reduce the contaminant element deposited on its surface. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay test was also used to observe the effect of these engineered specimens with respect to mesenchymal stem cells’ proliferation. Results and Discussion: The results show that ultrasonic cleaning and rotary tumbler polishing created a significant increase (90% and 67%, respectively) in the surface roughness. On the other hand, brushing was shown to be the best benchmark for reducing the contamination of Copper (Cu). Furthermore, rotary tumbler polishing and brushing can increase the percentage of living cells compared to the original surface EDM specimens. Conclusion: All micro-finishing methods that were employed are able to increase the surface roughness of Ti alloy based-implant to moderately rough category.
Pontificia Universidad Javeriana
2018-08-09 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/20574
Ingenieria y Universidad; Vol. 22 No. 2 (2018): July - December
eng
Copyright (c) 2018 Nanang Qosim
oai:ojs.revistas-javeriana.repositoriodigital.com:article/23665
2020-08-06T22:32:47Z
iyu:B%26CE
driver
"191206 2019 eng "
2011-2769
0123-2126
dc
Impact of substrates on the electrical properties of thin chromium films
Udachan, Shiva L.
Rani Channamma University https://orcid.org/0000-0002-0810-8353
Ayachit, Narasimha H.
Rani Channamma University https://orcid.org/0000-0002-5463-2586
Udachan, Lingappa A.
Rani Channamma University https://orcid.org/0000-0001-9028-9837
Objective: We studied the impact of substrates on the electrical properties of thin chromium films. Substrates may serve many purposes, such as to define orientation, to conduct electrical current in vertical devices, as a gate in transistors, etc. The thickness range of the chromium films grown on both substrates was (3.5-70) nm. Methods and materials: We used Fuchs-Sondheimer(FS) and Mayadas-Shatzkes(MS) theories to analyze electrical resistivity data for chromium(Cr) films grown on both substrates simultaneously by thermal evaporation in vacuum, under identical deposition conditions. Results and discussion: The infinitely thick film resistivity (ρ0), conduction electron mean free path(l), specularity parameter(p), scattering power of the grain boundary(α') and grain boundary reflection coefficient(R') were found to depend upon the nature of the substrate and the binding force between them and evaporated chromium atoms. The growth and microstructure of the chromium films were examined using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Conclusions: Our experimental data exactly fits with the MS theory in the entire thickness range grown for the chromium films deposited on both the substrates. Examination of film structure by SEM indicated that the films consist of grains of relatively pure chromium of different sizes, and depends upon deposition conditions and parameters, which are important factors that dictate the structural properties of the films.
Pontificia Universidad Javeriana
2019-07-02 00:00:00
application/pdf
application/xml
https://revistas.javeriana.edu.co/index.php/iyu/article/view/23665
Ingenieria y Universidad; Vol. 23 No. 2 (2019): July-December
eng
Copyright (c) 2019 Shiva L. Udachan, N. H. Ayachit, L. A. Udachan
oai:ojs.revistas-javeriana.repositoriodigital.com:article/25566
2021-10-22T01:51:14Z
iyu:B%26CE
driver
"200224 2020 eng "
2011-2769
0123-2126
dc
Development of a Chemical Equilibrium Model of the Downdraft Fixed Bed Gasification Process with known Product Temperature, Using air as an Oxidizing Agent
Quintero-Coronel, Daniel Andres
Universidad Francisco de Paula Santander Ocaña https://orcid.org/0000-0003-2822-5984
Espinel-Blanco, Edwin Edgardo
Universidad Francisco de Paula Santander Ocaña https://orcid.org/0000-0003-4479-2874
Flórez-Solano, Eder Norberto
Universidad Francisco de Paula Santander Ocaña https://orcid.org/0000-0003-2527-0413
A chemical equilibrium model for known outlet temperature of the products was carried out on a downdraft fixed bed gasifier. Biomass from oil palm kernel is used with proximate and ultimate analysis; the general gasification reaction takes into account the biomass moisture, the reaction products are formed by CH4, H2O, N2, CO, CO2 and H2. The model is described in detail and the equations are solved using the EES software. The model shows the results obtained for temperature ranges from 500 K to 1500 K and 1.0 atm. The model is validated by direct comparison of the gas composition with the results reported in the literature for similar conditions, obtaining favorable results.
Pontificia Universidad Javeriana
2020-12-22 00:00:00
application/pdf
application/xml
https://revistas.javeriana.edu.co/index.php/iyu/article/view/25566
Ingenieria y Universidad; Vol. 24 (2020): Continuous Publication
eng
Copyright (c) 2020 Daniel Andres Quintero-Coronel, Edwin Edgardo Espinel-Blanco, Eder Norberto Fl´órez-Solano
oai:ojs.revistas-javeriana.repositoriodigital.com:article/25964
2022-08-09T04:00:01Z
iyu:B%26CE
driver
"210617 2021 eng "
2011-2769
0123-2126
dc
Impact of Thickness on the Optical Properties of Selenium Thin Films
Udachan, Shiva
Rani Channamma University https://orcid.org/0000-0002-0810-8353
Ayachit, Narasimha
Rani Channamma University https://orcid.org/0000-0002-5463-2586
Udachan, Lingappa
Channabasaveshwar Arts, Science and Commerce College https://orcid.org/0000-0001-9028-9837
Halembre, Raghunanda
Government First Grade College https://orcid.org/0000-0003-1661-6566
Objectives: The primary objective of this investigation is to make a systematic study on the impact of thickness on optical properties, such as energy gap, absorption coefficient, optical density etc., for selenium thin films. Understanding of the band gap energy and its influence on film thickness is of utmost importance in acquiring the intended electrical characterization of semiconducting films. Materials and methods: Ultra-purity selenium (99.99 %) was deposited on glass substrates. During deposition, the glass substrate with its holder were rotated with constant speed to have a smooth coating. Results and discussions: The XRD findings indicate that selenium is amorphous in nature. The optical band gap energy is found to be decreasing form (2.3 to 2eV) with the rise of film thickness in interval (200 to 1000 nm). The band gap energy obeys inverse square law with respect to thickness. Conclusion: We have properly grown thin films of Se below the De Broglie wavelength limit by thermal evaporation in vacuum. The optical density varies directly with film thickness. The absorption coefficients were in the interval (0.5 to 4) × 107m-1. The AFM results confirmed that the Se nano-size increases with the increase in thickness. Both the grain boundaries and sub-grain regions are clearly visible in the SEM micrographs
Pontificia Universidad Javeriana
2021-10-12 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/25964
Ingenieria y Universidad; Vol. 25 (2021): Continuous Publication
eng
Copyright (c) 2021 Shiva Udachan, PhD, Narasimha Ayachit, PhD, Lingappa Udachan, PhD, Raghunanda Halembre, MSc
oai:ojs.revistas-javeriana.repositoriodigital.com:article/28069
2022-09-07T19:19:34Z
iyu:B%26CE
driver
"220712 2022 eng "
2011-2769
0123-2126
dc
Bio-Electrocatalytic Reduction of Hydrogen Peroxide by Peroxidase from Guinea Grass (Panicum Maximum) Immobilized on Graphene and Graphene Oxide Screen-Printed Electrodes
Castillo, John
Universidad Industrial de Santander https://orcid.org/0000-0002-6751-2305
Guarin-Guio, Paula Andrea
Universidad Industrial de Santander https://orcid.org/0000-0003-0845-2856
Ortiz, Ludy
Universidad Industrial de Santander https://orcid.org/0000-0001-8874-9427
Objective: In this article a comparison was made between graphene (SPGE) and graphene oxide screen-printed electrodes (SPGOE) to study the bio-electrocatalytic reduction of hydrogen peroxide (H2O2) by guinea grass peroxidase (GGP). Methods and materials: GGP was immobilized onto SPGE and SPGOE by a drop-casting procedure. Electrochemical techniques were carried out to monitor the electrochemical behavior of GGP and the efficiency of electrocatalytic reduction of H2O2. Results and discussion: GGP adsorbed on both electrodes exhibited a couple of well-defined redox peaks at 120 mV/10.5 mV and 184 mV/59 mV for anodic and cathodic peaks, respectively. Linearity between scan rates root and oxidation and reduction peak currents for both electrodes suggest a surface-controlled process. The GGP-modified electrodes exhibited a good electrocatalytic activity to H2O2 reduction at a redox potential of -0.6 V and -0.5 V for SPEG and SPEGO, respectively. Conclusions: SPGE and SPGOE electrodes modified with GGP showed excellent analytical performance towards different concentrations of hydrogen peroxide. This is a preliminary step to developing a bio-analytical portable system based on GGP for the detection of H2O2 in real environmental samples.
Pontificia Universidad Javeriana
2021-11-02 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/28069
Ingenieria y Universidad; Vol. 26 (2022): Continuous Publication
eng
Copyright (c) 2022 John Castillo, Paula Andrea Guarin-Guio, Ludy Ortiz
oai:ojs.revistas-javeriana.repositoriodigital.com:article/31433
2023-02-08T13:37:56Z
iyu:B%26CE
driver
"221216 2022 eng "
2011-2769
0123-2126
dc
Green Synthesis of Silver-Doped Titanium Dioxide Nanostructures for Acetaminophen Degradation Under Solar Radiation
Coronell , María
Universidad de Cartagena https://orcid.org/0000-0003-2760-5088
Toscano-Lucas, Gina
Universidad de Cartagena https://orcid.org/0000-0001-9332-6824
Solano, Ricardo
Universidad de Cartagena https://orcid.org/0000-0002-4528-2983
Herrera, Adriana
Universidad de Cartagena https://orcid.org/0000-0002-4355-3401
Objective: In this paper, the photocatalytic degradation of acetaminophen was evaluated using silver-doped titanium dioxide nanoparticles in a cylindrical-parabolic composed photoreactor. Materials and methods: Titanium dioxide was synthesized via green synthesis using Cymbopogon citratus leaf extract and doped by silver photodeposition. Results and discussion: Morphological information shows that large agglomerates of approximately 49 nm can be attributed to the strong interaction between nanoparticles and their polycrystalline nature. The photodeposition of metallic silver reduces the surface effects, allowing a decrease in the electrostatic interaction and diameter size of the titanium dioxide, as well as the optical properties due to surface poising during the reduction of silver ions to metallic silver. The photocatalytic activity was performed to degrade acetaminophen as the drug model under visible-light radiation. The results are promising, with superior photodegradation of acetaminophen of approximately 37% and 11% for unmodified titanium dioxide and silver-doped titanium dioxide (0.75 at%) nanostructures compared to the commercial photocatalyst, respectively. Conclusions: Accordingly, the potential photocatalytic application of silver-doped titanium dioxide nanostructures is highlighted and represents a promising alternative for the photodegradation of organic compounds from wastewater eluents.
Pontificia Universidad Javeriana
2021-11-02 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/31433
Ingenieria y Universidad; Vol. 26 (2022): Continuous Publication
eng
Copyright (c) 2023 María Coronell, BSc, Gina Toscano-Lucas, BSc, Ricardo Solano, MSc, Adriana Herrera, PhD
oai:ojs.revistas-javeriana.repositoriodigital.com:article/33790
2023-10-26T02:52:09Z
iyu:B%26CE
driver
"230901 2023 eng "
2011-2769
0123-2126
dc
Control charts to establish and monitor proficiency in the detection of pulmonary B-lines with Point of Care Ultrasound
Usaquén-Perilla, Sandra Patricia
Universidad del Valle; Universidad Militar Nueva Granada https://orcid.org/0000-0003-1614-1898
Ropero-Rojas, Deliana
Universidad del Valle https://orcid.org/0000-0003-1879-4083
Mosquera-Restrepo, Jaime
Universidad del Valle https://orcid.org/0000-0002-8404-2472
Kirsch, Jonathan D.
University of Minnesota https://orcid.org/0000-0003-0185-8001
Kaltenborn, Zachary P.
University of Minnesota https://orcid.org/0000-0002-2250-6788
García-Melo, José Isidro
Universidad del Valle https://orcid.org/0000-0003-1672-7768
Osorio-Amaya, Lyda Elena
Universidad del Valle https://orcid.org/0000-0002-5121-4741
Objective: Point of care ultrasound (POCUS) is a widely used clinical tool. This operator-dependent technique requires methods to establish individual benchmarks and to monitor the learning process. We present the use of the learning curve standard cumulative summation (LC-CUSUM) and CUSUM control charts to establish and monitor, respectively, the proficiency of a physician to detect pulmonary B-lines with POCUS. Materials and Methods: A training course for general practitioners was conducted to detect plasma leakage using POCUS. The trainees and an expert radiologist identified the number of pulmonary B-lines in the POCUS images of 53 hospitalized patients. The interpretation of one trainee was compared to that of the expert radiologist using LC-CUSUM and CUSUM considering image quality and anatomical site. Results and Discussion: We found that image quality was better in the apices than the bases of the lungs. The trainee learning curve differed by anatomical site and the results of LC-CUSUM and CUSUM differed when only high-quality (first scenario) or all images (second scenario) were included in the analysis. Conclusion: The LC-CUSUM and CUSUM control charts were useful to evaluate the learning curve in this case and to identify image quality as an important factor in the evaluation process. They warrant further study as graphical tools for real-time monitoring of POCUS training.
Pontificia Universidad Javeriana
2023-09-01 00:00:00
application/pdf
https://revistas.javeriana.edu.co/index.php/iyu/article/view/33790
Ingenieria y Universidad; Vol. 27 (2023): Continuous Publication
eng
Copyright (c) 2023 Sandra Patricia Usaquén-Perilla, MSc, Deliana Ropero-Rojas, PhD, Jaime Mosquera-Restrepo, PhD, Jonathan D. Kirsch, MD, Zachary P. Kaltenborn, MD; José Isidro García-Melo, PhD; Lyda Elena Osorio-Amaya, PhD