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Diseño y ánalisis de experimentos
... La presente investigación tuvo un enfoque cuantitativo, experimental con diseño de superficie de respuesta (MSR) una colección de técnicas matemáticas y estadísticas útiles en la estrategia experimental y de análisis que permiten encontrar las condiciones de operación óptimas de un proceso, [37]. ...
... Hay dos tipos principales de diseños, el diseño central compuesto y el diseño de Box-Behnken. Para la investigación se seleccionó el diseño central compuesto (DCC) por que puede ajustarse a un modelo cuadrático completo, [37]. ...
... La región de operabilidad fue delimitada por las condiciones donde el equipo o proceso puede ser operado, [39]. El nivel de significancia (α) es la distancia de cada punto axial desde el centro de un diseño central compuesto, un valor igual a uno los coloca en las caras del cubo y se utiliza con 3 niveles de cada factor, [37]. Se seleccionó esta metodología porque los puntos axiales fuera del "cubo" no están en la región de operabilidad, por restricciones del producto. ...
... El tipo de diseño experimental seleccionado es el factorial, cuyo objetivo consiste en estudiar el efecto de varios factores sobre una o varias respuestas (Throughput). Es decir, se busca estudiar la relación entre los factores y la respuesta, con la finalidad de comprender mejor cómo es la relación y generar conocimiento que permita tomar acciones y decisiones que mejoren el desempeño del proceso [7]. ...
... Un diseño de experimentos factorial o arreglo factorial es el conjunto de puntos experimentales o tratamientos que pueden formarse y considera todas las posibles combinaciones de los niveles por el número de factores [7]. Los factores son aquellas variables que se investigan en el experimento, con relación a la forma como afectan a la(s) variable(s) de respuesta. ...
... El nombre de análisis de varianza (ANOVA) viene del hecho que se utilizan coeficientes de varianzas para probar la hipótesis de igualdad de medias. La idea general de esta técnica es separar la variación total en las partes con la que contribuye cada fuente de variación en el experimento [7], [9]. El análisis de varianza, permite identificar si las muestras tomadas en diferentes situaciones llamadas "factores" o "tratamientos", influyen significativamente desde un punto de vista estadístico sobre la variable respuesta. ...
El rendimiento es sin duda uno de los aspectos de mayor interés dentro del análisis global en las redes LAN, considerado el efecto que produce sobre el usuario final. El rendimiento puede ser definido según diversos puntos de vista, lo que permite incorporar otras formas de evaluación según el objeto de interés en particular. Básicamente, los parámetros más comunes para evaluar el rendimiento de una red son: Throughput, utilización del canal y diversas medidas de retardo. Throughput, es la capacidad de un enlace de transportar información útil. En otras palabras, representa “la cantidad de información útil que puede transmitirse por unidad de tiempo”. Este puede variar en una misma conexión de red según el protocolo usado para la transmisión (TCP o UDP) y el tipo de datos de tráfico (HTTP, FTPy otros). Un objetivo muy importante al analizar el throughput se encuentra relacionado con la calidad del servicio (QoS / Quality of Service) en la red, la cual juega un papel importante a la hora de evaluar la eficiencia de una red centrada en aplicaciones sensibles al tiempo, tales como: video y audio, entre otras. Desde el punto de vista tecnológico, el hacer uso de la red eléctrica como medio físico de transmisión ha sido considerado como una excelente alternativa en la prestación de servicios de interconexión de última milla. El uso de adaptadores de red basados en PLC facilita el diseño de redes LAN y comunicaciones de banda ancha a través de la red eléctrica, al convirtir cualquier tomacorriente en un punto de conexión para el usuario, sin la necesidad de cableados adicionales a los existentes. Este artículo presenta un análisis experimental sobre el comportamiento del Throughput en redes LAN sobre PLC, bajo el uso de adaptadores de red soportados con el estándar HomePlug 1.0.
... Así entonces, el propósito del diseño experimental es la obtención del máximo de información con el mínimo de costo y el máximo de eficiencia [210]. El diseño y análisis estadístico de los experimentos se realiza en varias etapas, las cuales describió Montgomery [212] en siete fases. ...
... La sexta etapa consiste del análisis de datos el cual se realiza, generalmente, empleando softwares estadísticos. Finalmente, la última etapa tiene que ver con las conclusiones obtenidas a partir del análisis de datos del diseño de experimentos y recomendaciones que surjan para estudios posteriores [212]. ...
... Cuando la mayor parte de la variabilidad observada se debe a factores no estudiados o a un error no aleatorio, no se podrá distinguir cuál es el verdadero efecto que tienen los factores estudiados, con lo que el experimento no alcanzaría su objetivo principal. Esto muestra la importancia de no ignorar factores que puedan influir de manera significativa sobre el comportamiento de la respuesta [211,212]. Un experimento debe ser reproducible, y debe realizarse de forma aleatoria, garantizando que los resultados no estén sesgados al sujeto que realizó el diseño y el muestreo [210,212]. ...
Esta obra muestra el gran potencial que tienen las materias primas colombianas para la síntesis de productos de la química fina tal como el nopol, utilizando catalizadores heterogéneos. El nopol tiene aplicaciones relevantes en la industria de aromas y fragancias, pero también puede ser utilizado como intermediario en la síntesis de productos empleados en la producción de pesticidas y productos del hogar. Por otra parte, se muestra una caracterización detallada del material Sn/MCM-41, a partir de la estructura cristalina, la morfología, las propiedades texturales, la fuerza y tipo de sitios ácidos, y el tipo de especies activas. Este catalizador se sintetiza utilizando silicato de sodio producido en Colombia, como fuente de silicio, lo cual es significativamente más económico que la fuente de silicio tradicional, tetraetil ortosilicato. Finalmente, se realizó un estudio detallado con aceite de trementina como fuente de β-pineno y paraformaldehído comercializado localmente, mediante un Diseño Central Compuesto, determinando condiciones óptimas para la producción de nopol.
... As a consequence, tempering temperatures are recommended. This coefficient is estimated as in Equation (3) and results from Tables 2 and 3, which list the temperature-time and ADI hardness Pearson correlation, that is, the type of relationship between variables and the kind of increase among them, respectively, in agreement with [56,57] ...
... where and are the standard deviations, and the covariance of " " and " ", correspondingly [57]. ...
... As a consequence, tempering temperatures are recommended. This coefficient is estimated as in Equation (3) and results from Tables 2 and 3, which list the temperature-time and ADI hardness Pearson correlation, that is, the type of relationship between variables and the kind of increase among them, respectively, in agreement with [56,57]. ...
This research evaluates the effect of temperature and time austempering on microstructural characteristics and hardness of ductile iron, validating the results by means of a statistical method for hardness prediction. Ductile iron was subjected to austenitization at 950 °C for 120 min and then to austempering heat treatment in a salt bath at temperatures of 290, 320, 350 and 380 °C for 30, 60, 90 and 120 min. By increasing austempering temperature, a higher content of carbon-rich austenite was obtained, and the morphology of the thin acicular ferrite needles produced at 290 °C turned completely feathery at 350 and 380 °C. A thickening of acicular ferrite needles was also observed as austempering time increased. An inversely proportional behavior of hardness values was thus obtained, which was validated through data analysis, statistical tools and a regression model taking temperature and time austempering as input variables and hardness as the output variable, which achieved a correlation among variables of about 97%. The proposal of a mathematical model for the prediction of hardness in austempered ductile iron represents a numerical approximation which validates the experimental results at 95.20%.
... However, to date, we have not found statistics indicating how much the concentration levels of particulate matter PM 2.5 , PM 10 , and the pollutant NOx decrease as a result of a transport electri cation policy. In this work, we indirectly calculate the maximum level of reduction in the concentration levels of pollutants PM 2.5 , PM 10 , and NOX that can be aspired to as a result of an eventual policy of electri cation of public transport, it seeks to reduce the levels of circulation and mobility of gasoline vehicles. ...
... No other initiative has contributed to improving air quality and reducing the concentration levels of pollutants PM 2.5 , PM 10 Although the empirical evidence reported so far indicates large bene ts and improvements in the reduction in the concentration of particulate pollutants, in the USA particulate matter such as PM 2.5 did not report signi cant decreases (Archer et al., 2020). ...
... We contribute to the literature by providing an estimation of the impact in terms of the maximum level of reduction of the concentration level of PM 2.5 , PM 10 , and NOx that can be expected as a result of policies related to mobility restrictions and/or the renewal of the conventional vehicle eet by electric vehicles as a long-term policy. The rest of the document is structured as follows: Section 2 describes the case study, the data, and the methodology used. ...
We use official data from the Chilean Government's National Air Quality Information System (SINCA) for the Metropolitan Region of Santiago and estimate the impact of COVID-19 confinement on the variation in concentration levels of particulate matter PM 2.5 and PM 10 . We also measured the impact on the variation of NOx levels. All three pollutants are related to the transport sector. We found that overall, there is a significant difference between the average concentration levels of particulate matter PM 2.5 and PM 10 reported in 2019 and 2020. As well as the concentration levels of NOx, in the periods, indicated. In particular, we found that, for the months of total confinement, May-July, monthly average levels decreased between 7% and 19% for particulate matter PM 2.5 ; between 18% and 50% for particulate matter PM 10 and between 34% and 48% for NOx gas. These results represent the maximum indirect impact that can be expected in reducing the concentration levels of these pollutants as a result of an eventual transport policy aimed at reducing the concentration levels of PM 2.5 , PM 10 , and NOx in the city of Santiago de Chile.
... Ejemplo: el peso, la talla, la altura, la presión arterial, entre otros. [1][2][3] [5] c. Variables independientes: son variables utilizadas por el investigador del experimento con el fin de manipular y estudiar la incidencia en las variables dependientes. ...
... Son propiedades o características observadas, medidas que se tratan de cambiar, para determinar el efecto de las variables independientes en el experimento.[1][5] e. Variables extrañas: Son variables independientes no relacionadas con el objetivo del estudio o experimento, pero que puede presentar efectos sobre las variables dependientes.Las escalas de medición determinan los métodos estadísticos que se usan para analizar los datos. ...
El proyecto es multidisciplinario, pues convergen las temáticas de Ingeniería de Sistemas, la Comunicación Social y la Estadística. Y también es interinstitucional, dado que unieron fuerzas el programa de Comunicación Social-Periodismo y el área de Estadística de la Facultad de Ciencias Básicas de la Universidad Autónoma de Occidente, así como los grupos de investigación LIDIS de la Universidad de San Buenaventura-Cali y COMBA I+D de la Universidad Santiago de Cali.
... Las componentes de varianzas son posibles de obtener con estimaciones de máxima verosimilitud (REML) en el contexto de los modelos lineales mixtos. Estos se utilizan para establecer los tamaños muestrales mediante curvas características de operación (Montgomery, 2004), calcular repetibilidad genética (Arief et al., 2015), estimar la eficiencia de los ensayos en cuanto a la cantidad de repeticiones, localidades y años de evaluaciones que deben realizarse (Yan et al., 2015;Baxevanos et al., 2017;Woyann et al., 2020). Las varianzas del error son usadas para determinar el error estándar de la diferencia porcentual entre la media de un cultivar y la media de una cantidad especificada de cultivares controles (Patterson et al., 1977). ...
... El análisis del rendimiento se realizó para cada combinación de sitio, manejo y época de siembra, con el conjunto de cultivares, y particionando los cultivares por grupo de calidad. Las componentes de varianzas estimadas se utilizaron para estimar la mínima cantidad de años de evaluación, para cada ensayo de la RET, por tres métodos complementarios: a) Potencia de prueba (j) a través de curvas características de operación (Montgomery, 2004), mediante las cuales se calculó la cantidad de años de evaluaciones necesaria para alcanzar una j> 90 % al identificar diferencias de rendimiento entre cultivares. Para ello, se calculó el parámetro l para el factor año (aleatorio), mediante la siguiente ecuación: ...
En Argentina, la normativa vigente establece cuatro años de evaluación de rendimiento para cualquier nuevo cultivar comercial de trigo pan. El objetivo de este trabajo fue determinar la cantidad óptima de años de evaluación en ensayos comparativos de rendimiento de cultivares de trigo pan, condicionando dicho óptimo al grupo de calidad, ciclo de crecimiento y manejo fitosanitario. Se estimaron componentes de varianza (REML) con los datos de la Red de evaluación de cultivares de trigo pan de Argentina (RET), correspondientes a diez sitios experimentales. Se consideraron los tres grupos de calidad (GC1, GC2 y GC3), la primera y tercera época de siembra (E1 y E3), y manejo con y sin fungicida (CF y SF). Los resultados muestran que se requieren tres años de ensayos para evaluar el rendimiento de los diferentes grupos de calidad y ciclos de crecimiento manejados CF. Para el SF, se requieren cuatro años, excepto para GC1 en E3 y GC2 en E1, que demandan tres y más de cinco años, respectivamente. Estos resultados indican que la norma actual es apropiada para la mayoría de los casos; incluso, podría reducirse a tres CF, para mejorar la calidad de los ensayos y aumentar el número de repeticiones.
... Los datos se procesaron con el programa estadístico Infostat (Di Rienzo et al. 2017). En el primer ensayo, las medias se compararon mediante contraste ortogonal (M1 vs. M2, M3, M4, M5, M6 y M7) por la prueba de Scheffé (Montgomery 2004). En el segundo, la comparación de medias entre los tratamientos se realizó mediante la prueba de Duncan (1955). ...
... The data was processed with the statistical program Infostat (Di Rienzo et al. 2017). In the first test, means were compared using orthogonal contrast (M1 vs. M2, M3, M4, M5, M6 and M7) by Scheffé's test (Montgomery 2004). In the second, the comparison of means between treatments was performed using Duncan (1955) test. ...
In order to select a non-conventional culture medium for the growth of Pichia guilliermondii LEVICA-27 as an activator additive for ruminal fermentation, two trials were carried out in which YPG medium was used (yeast extract 10 g/L, peptone 10 g/L and glucose 20 g/L) as control medium. In the first, seven culture media were evaluated for yeast growth at 24 hours of fermentation. While in the second, growth kinetics was performed in the selected medium of the first test. In addition, in the latter, the maximum specific growth rate, the biomass doubling time, and the stoichiometric balance of the selected medium were determined. At 24 hours of fermentation, there were not differences between the media studied and the YPG medium (p=0.073). Therefore, the latter can be replaced without affecting the strain growth in 24 h. In the kinetic study, there was a higher microbial concentration at 12 h (P<0.0001) in the medium containing molasses and urea. The maximum specific growth rate was lower (P=0.0260) and the biomass doubling time was higher (P=0.0283) with respect to the control. The selected medium constitutes an adequate option for the production of LEVICA-27, since it allows obtaining good cell concentration, covering the nutritional requirements and includes fewer components in its preparation. This offers economic and operational advantages for obtaining the additive at production scales.
... En ese contexto, con excepción de los reportes de Rivera (2008Rivera ( , 2009) para el sector occidental de la Bahía de Jiquilisco, no se dispone de registros nacionales de la pesca de Ucides occidentalis. No obstante, la producción bibliográfica que incluye información sobre la especie, consiste en estudios monográficos de cangrejos brachiuros y anomuros (Holthuis, 1954;Bott, 1954;Haig, 1960Haig, , 1968Ball, 1972;Ball & Haig, 1974;Efford, 1976;Gore, 1982;Orellana, 1977Orellana, , 1992 y en los estudios poblacionales (Aparicio & Pleitéz, 1993;Pocasangre & Granados, 1995;López, 1997;Carranza, 1998;Carranza & Mejía, 2001, 2002Carranza, 2004;Rivera 2008, 2010a, Rivera & Córdova, 2010. ...
... Los organismos analizados en este estudio fueron recolectados de nueve estaciones de muestreo (cuadro 5, figura 11), localizadas en el ecosistema de manglar de la cuenca baja del El valor del coeficiente de regresión (β) se evaluó con una prueba "t" de Student (Zar 1999), para determinar el tipo de crecimiento que exhibe la especie; si β = 3 el crecimiento es isométrico y si β ≠ 3 el crecimiento es alométrico (Ricker, 1975;Ramos-Cruz, 2008). Para evaluar el efecto del sexo en la longitud de los organismos se realizó un análisis de covarianza (ANCOVA), utilizando al peso como la variable covariante (Montgomery, 2002). ...
A research report on " Sustainable Fisheries Management of Ucides occidentalis ("punche"), hydro-biological resources of Rio Lempa downstream, Jiquilisco Bay, Usulutan" is presented. This study encompasses the following objectives: a) to determine the parameters growth and the relationship between the biometric measurements, b) estimate the probability of capture and mortality rates and recruitment, c) assess the current rate of resource exploitation and, d) design a proposal for Sustainable Fisheries Management to be submitted for consideration by authorities.
The study included analysis of 1,460 individuals, collected in July-August 2007, February�March 2008, February 2009-August 2010 and February-April 2012. 682 organisms were females (47%) and 778 (53%) males. The average width of carapace was 62.15 mm with a weight of 106.88 g. Generally, males were larger and heavier than females in this species. The historical records showed that measures of carapace width and weight gradually increased from 2007 to 2012. Also, the analysis revealed the ecosystem present four sectors two north and two south of Izcanal estuary. It was also observed that organisms are influenced by seasonality, expressed by the rainy, dry and transitional seasons. This species exhibits a negative allometric growth, indicating that grow of this specie, is less in proportion to its size, probably by limitations of food in the ecosystem. The growth rate was estimated at 0.20, is evidence of low growth. The organisms of 77 mm have a 75% chance of capture and this group has received most fishing pressure. The recruitment pattern, in other words, the entry of reproductive specimens occurs from January to November, but mostly occurs between March and June. The exploitation rate calculated in this study is very close to over-exploitation limit, which would affect the viability of the population; this could be corrected to take action to increase the average width of the carapace of specimens caught in artisanal fisheries. A tangible contribution of this research to the sustainability of small-scale fishing of this
species, was made an approach of sustainable fisheries management, based on levels that biological, ecological and socio-economic, sets targets, activities, dates of execution,
responsible and indicators, for the achievement the follow objectives: a) Keep the stock at
sustainable levels, b) develop fishing activities in harmony with the ecosystem, c) Promote economic efficiency of fishing and, d) establish effective mechanisms for user participation. Additionally, a form of local monitoring of the population of Ucides occidentalis was developed and validated, to be implemented by rangers in the area, to record catches and evaluate the effect of real-time fishing and generate information locally to make decisions.
... The design of experiments refers to the process of designing and conducting experiments in such a way that adequate data are collected that can be analysed with statistical methods to obtain valid and objective conclusions. (Montgomery, D.) [1] A natural starting point for the design of experiments in agriculture is the excellent review by Verdooren (Verdooren, LR) [2] who tracks development from ancient times through to the advent of Sir RA Fisher in 1926, which represents the start of modern statistical design. The design of experiments can be used as a statistical simulation tool, in which the parameters can be changed, and different results observed; in agriculture it allows us to approach the ideal parameters without having to wait for the sowing -harvest cycle to end to analyse the results, this allows us to dramatically reduce research and development time (Almaguer, C. et al) [3]. Figure 1 shows the precision agriculture timeline. ...
... The nature of the data in CAETEC does not allow the use of regression analysis and hence Design of experiments was proposed. According to Montgomery [1] the guidelines for Designing and Experiment is given by: 1. Recognition of and statement of the problem Pre-experimental 2. Selection of the response variable 3. Choice of factors, levels, and ranges 4. Choice of experimental design 5. Performing the experiment 6. Statistical analysis of the data 7. Conclusions and recommendations The purpose of this article is to design jointly with CAETEC and the School of Engineering and Sciences of the Tecnologico de Monterrey until step 4, that is, until the selection of the experimental design. ...
... In order to find a combination of factors that maximize the response variables, the results were analyzed according to the multiple response optimization methodology, finding a set of operating conditions that optimize all responses, according to the use of the desirability functions. These functions are a method that assigns a score always between 0 and 1 to a set of responses variables and chooses factors that maximize that score (1 represents a completely desirable value) (Felix et al., 2018;Montgomery, 2003;Candioti et al., 2014). Finally, an experimental validation was carried out with the optimal conditions for each factor. ...
... The mathematical model of the response surface for the TPC (Equation 4) had a coefficient of determination (R 2 ) close to 1, a high F-value, and a p-value < 0.05 (Table 2), which shows that this model is adequate to describe the values obtained for the extraction of total polyphenols from feijoa epicarp. The p-value for lack of fit was not significant indicating that the response surface mathematical model can be used for optimization (Khajeh, 2011;Montgomery, 2003). ...
Feijoa residues has a high content of bioactive compounds with effective antioxidant activity compared with the content of other
fruits. However, these wastes are disposed of without generating added value. Therefore, in order to determine the maximum time
to extract the polyphenols (TPC) and flavonoids (TFC) present in the residue, solid-liquid extraction kinetics was performed.
Next, in order to find the best conditions for maximizing the simultaneous extraction of TPC and TFC, a central composite
design and response surface analysis were proposed. Three independent factors, temperature (ranging from 13.18 to 46.82 °C),
solid:liquid ratio (ranging from 1:10 to 1:74 g:mL) and ethanol-water mixture (ranging from 16,36 to 83,64%v/v) were evaluated.
The kinetics indicated a maximum extraction time of 90 minutes for TPC with 3,990.02 ± 22.403 mgGAE/100 g FW, and
45 minutes for TFC with 1,219.38 ± 19.24 mgCE/100 g FW. These values are within the range reported by other studies using
advanced technology. The optimized extraction conditions were a temperature of 34.5 °C, 1:45 solid-liquid ratio and 39.43%
for the solvent. Finally, extract from feijoa residues presented an effective antioxidant activity greater than 50%. Therefore, this
residue can be used as a promising source of bioactive compounds with various agro-industrial applications.
... Analytical measurements of fruit weight were randomly repeated for each variety of S. caripense (1000 fruits). The data were disposed under CRD in a factorial experiment 3 x 2 with three genotypes (Var.) and two altitudes (m.a.s.l.) for analysis with the mean values into a linear additive statistic model 47,48 . Thus, there are three effects of interest without considering decomposition and three null hypotheses raised with their corresponding alternative hypothesis. ...
The current project addresses the great potential of S. caripense Dunal (Tzimbalo) for intraspecific breeding and interspecific gene flow towards the related commercial crop S. muricatum Aiton (Pepino) to develop fruits with improved antioxidants, flavor, and fruit weight. This study aims to determine the interaction between genotype x altitude and identify significant differences between treatments according to fruit weight. Tzimbalo varieties GenPurpura, Gennbiotz, and GenDulce, were used. Fruit weight was analyzed using a factorial experiment under a completely randomized design (CRD). The interaction Var. x m.a.s.l. was significant (mean ± SE), Gennbiotz:a1 (4.88 g ± 0.44; C) and GenDulce:a2 (4.38 g ± 0.25; BC), followed by GenPurpura:a1 (3.33 g ± 0.36; AB); also the principal effect Var. was significant, Gennbiotz (3.93 g ± 0.23; B) and GenDulce (3.64 g ± 0.25; B), followed by GenPurpura (2.90 g ± 0.19; A). These results demonstrate distinctness, uniformity, and stability (DUS) of at least one tzimbalo variety. Fruit weight and other characteristics are relevant to improve quality and commercial potential. They are used to develop biofortified beer, jam, ice cream, and plant tissue culture media with sucrose and vitamins to strengthen biotechnological production in Cotopaxi-Ecuador. Keywords: factorial experiment; tzimbalo varieties; fruit quality; genotype; agri-biotechnology.
... The data obtained were statistically analyzed by one-way analysis of variance (ANOVA). Differences between means were identified by applying Duncan's multiple range method using the Statgraphics Plus 5.1 software package [27]. ...
In this work, the interactions and functional properties of the mixed hydrocolloid system (MHS) formed by the limited protein hydrolysate of hard-to-cook Phaseolus vulgaris (LHv) and carboxymethylated galactomannan from flamboyant seed (CGF) were studied at pH values of 3, 3.5 and 4. An LHv with a degree of hydrolysis of 8.3% and a CGF with a degree of substitution of 0.91 was obtained. By fluorometry, the highest interaction between LHv and CGF was observed at pH 3 and decreased with increasing pH; furthermore, the soluble nitrogen of MHS was higher than that of LHv and increased with pH. The MHS had a higher foaming capacity and stability than the LHv dispersion; it was also observed that the stability increased with increasing pH of the system, reaching a foaming capacity of up to 267% and a stability time of 35 min with the MHS at pH 4. On the other hand, the emulsifying activity index (EAI) of MHS and LHv increased with increasing pH, with MHS reaching 219% EAI; whereas, the emulsifying stability index (ESI) of MHS increased slightly with pH value. Based on the results obtained, the use of MHS in food industry products where foam control or emulsion generation and stabilization are required, could be considered. Abbreviations MHS: Mixed hydrocolloid system; LHv: Limited protein hydrolysate of hard-to-cook Phaseolus vulgaris; CGF: Carboxymethylated galactomannan from flamboyant seed; EAI: Emulsifying activity index; ESI: emulsifying stability index; PCv: protein concentrates of hard-to-cook P. vulgaris; Trp: Tryptophan; DH: degree of hydrolysis; MFG: Modified flamboyant gum
... The assumption of homogeneity of variance was verified with the Bartlett test. In cases in which the data did not meet this assumption, they were subjected to the Kruskall Wallis test (p < 0.05) with the Infostat program at a confidence level of 95% (Montgomery 1991;InfoStat Statistical Software 2002). Only the modulus of elasticity comparison between the non-inoculated treatments for both irrigation conditions was analyzed by means of a one-way ANOVA, to evaluate the effect of water stress on this variable in the onion crop due to the trend observed in its twoway ANOVA (Blanco et al. 2021a). ...
Synergistic studies of microorganisms in the last decade have been mostly directed towards their biofertilizing effects on
growth and crop yield. Our research examines the role of a microbial consortium (MC) on physiological responses of Allium
cepa hybrid F1 2000 under water and nutritional deficit in a semi-arid environment. An onion crop was established with
normal irrigation (NIr) (100% ETc) and water deficit (WD) (67% ETc) and different fertilization treatments (MC with 0%,
50% and 100% NPK). Gas exchange (Stomatal conductance (Gs), transpiration (E) and CO 2 assimilation rates (A)) and leaf
water status were evaluated throughout its growth cycle. The MC + 50% NPK treatment with NIr maintained similar A rates
to the production control. A. cepa decreased Gs by approximately 50% in the WD treatment. The highest water use efficiency
(WUE) and an increase in the modulus of elasticity in response to water stress were obtained for the 100% NPK treatment
under non-inoculated WD. The onion hybrid F1 2000 was tolerant to water stress and under non-limiting nutrient conditions, irrigation may be reduced. The MC facilitated the availability of nutrients under NIr allowing a 50% reduction in the
application of high doses of fertilization without affecting yield, resulting in a suitable agroecological strategy for this crop.
Keywords CO2 assimilation · Leaf conductance · Onion · Nutrient stress · PGPR · Water stress
... Therefore, the experimental data obtained from the design (Table. 1) were fitted to a polynomial of the form found in equation 4 [26]. ...
The response surface methodology (RSM) was applied to optimize the effects of immersion time (01, 02 and 03 hr), temperature (40, 50 and 60 ⁰C) and concentration of sucrose solution (40, 50 and 60⁰Brix) in osmotic dehydration of mango fruit slices (3mm thickness). Box-Behnken Design was used with water loss (WL, %), solid gain (SG, %), and weight reduction (WR, %) as responses. The models obtained for all the responses were significant (P≤0.05) without a significant lack of fit. The optimum conditions were temperature (50°C), immersion time (2hr), concentration of sucrose solution (56.756⁰Brix) in order to obtain WR of( 32.75 g/100g initial sample), SG of (18.799g/100g initial sample) and WL of (51.551g/100g initial sample), respectively.
... Por medio de un diseño de experimentos factorial utilizando la herramienta Minitab® se determinan los factores y las interacciones entre los mismos que establecen cada parámetro de respuesta, para de esta forma obtener las ecuaciones de regresión correspondientes. Finalmente, se optimizan las respuestas para cumplir con los criterios de funcionamiento del impulsor axial sin eje central y analizar su factibilidad de uso en un dispositivo de asistencia ventricular [12,13]. ...
Este artículo abarca la obtención de los modelos matemáticos para las respuestas de deformación volumétrica, diferencia de presión y caudal de un impulsor axial diseñado para un dispositivo de asistencia ventricular. Dicho impulsor posee una geometría novedosa que requiere la validación de su comportamiento a nivel estructural y de dinámica de fluidos. Basándose en las especificaciones requeridas para la aplicación se obtiene el punto de operación óptimo del impulsor en cuanto a su velocidad de rotación, material y velocidad de salida del flujo sanguíneo. Asimismo, se obtiene el rango de valores de los factores que cumplen con las especificaciones. Dentro de los materiales incluidos se tiene el Platino y el polímero biocompatible Peek. El análisis se realiza por medio de un diseño de experimentos factorial completo, con resultados obtenidos previamente utilizando herramientas de simulación. La obtención de los modelos matemáticos se realiza por medio de la depuración de los factores de entrada y sus interacciones.
... Para estudiar el efecto de las variables de proceso en la simulación del proceso de secado del gas natural, se estableció un diseño de experimento fraccionado Tabla 2 (Montgomery, 2014). Se establecieron como variables de estudio: presión de operación de la columna, flujo de DEG y número de platos. ...
Simulación del proceso de deshidratación de gas natural complejo Maloop El gas natural que se produce en el complejo Maloop contiene humedad por arriba de 1% molar, para cumplir con las normas de control de calidad y evitar la formación de hidratos a través de las redes marinas de distribución, es importante que el proceso de deshidratación sea eficiente. Palabras clave: Aspen Hysys, Energía, Columna de absorción, Di-etilenglicol, Optimización proceso The natural gas produced in the Maloop complex contains humidity above 1% molar, to comply with quality control standards and avoid the formation of hydrates through marine distribution networks, it is important that the Dehydration process be efficient.
... To evaluate the effect of the concentrations of Yungay potato starch, aloe vera gel, and graphene on the mechanical properties, and biodegradability of the films, an experimental design was proposed through a factorial design 2 ˄ 3 with three factors: the starch concentration (%w/w), the aloe concentration (%w/w) and the graphene concentration (%w/w), of two levels for each factor: high level (+) and low level (-) as shown in Table 1. A 2 ˄ 3 design was chosen since it allows estimating the effects of the independent variables and the combination of them, on the response variables with fewer experiments, it is cheaper and with the same precision than studying them separately [26] . The range of graphene concentration was considered from 0.005 to 0.045%w/w since at graphene concentrations above 0.045%w/w formed brittle films and were not homogeneous. ...
Abstract Currently there is a great trend towards cleaner, more sustainable and green production, based on a circular economy. Therefore, in the present work the study of the effect of the concentration of potato starch, aloe vera and graphene on the mechanical properties, water vapor permeability, biodegradability and structural properties of bioplastics is reported. These bioplastics could replace conventional synthetic plastics that currently produce high environmental pollution. According to the statistical analysis of a 2˄3 factorial design, a biodegradable bioplastic with improved mechanical properties was obtained, with a high maximum stress of 2.49 ± 0.28 MPa at high concentration levels of starch, aloe vera and graphene (10% w/w starch, 24% w/w of aloe and 0.045% w/w of graphene). A minimum value of permeance and permeability to water vapor of 5.35 kg/h.kPa.m2 and 0.001839 kg/h.kPa.m, respectively, was found at a graphene concentration of 0.005%; aloe concentration, 24%; and starch concentration, 10%.
... To determine if the anthocyanin extraction levels were within the region of maximum yield, the fit was made to a second-order polynomial model [19] (Table 3). ...
In the present work, the anthocyanin extraction process was characterized during the elaboration of a purple corn drink, using the response surface analysis method with temperature intervals between 47.57 and 132.43°C, and times from 11, 36 at 138.64 minutes. In addition, with the stationary point technique, the maximum retention of anthocyanin (33.99 mg/g) was determined at a temperature of 98.39°C at a time of 105.89 minutes of extraction. Since this time is too long and to reduce production costs, without resorting to considerable losses of anthocyanins, canonical analysis was used, redefining the optimal extraction parameters at a temperature of 100°C for 60 minutes with a reduction of the anthocyanin content of 2.49% (33.14 mg/g) concerning the maximum, a value that is within the optimum area of performance of the process. With the extract obtained under optimal conditions, a drink was prepared and, using the differential pH method and Student’s t-test (p = 0.05), its anthocyanin content was quantified and compared with that of a commercial drink with typical characteristics. Similar, observing that the elaborated drink presents higher contents, whose difference varies within the range of 2.79 and 4.72 mg/mL. Finally, using a satisfaction test with a nine-point hedonic scale, it was determined that the beverage was “very well liked” by a semi-trained sensory panel.
... En esta investigación se modeló el comportamiento de las variables consideradas dependientes versus las variables consideradas independientes a través de un modelo de regresión lineal múltiple. Para determinar el modelo matemático más adecuado existen varias técnicas, una de ellas es el procedimiento de selección hacia atrás, según Montgomery (2004). Con la ayuda del programa Statgraphics Centurion XVI (2016), mediante el empleo del análisis de regresión no lineal y la función logarítmica en función de las variables independientes, se obtuvieron las potencias del mejor ajuste para las variables dependientes. ...
Este artículo presenta la modelación matemática de un sistema de enfriamiento con rueda desecante como alternativa para la climatización de edificaciones en climas cálidos y húmedos. El sistema modelado está conformado por los siguientes elementos fundamentales: una rueda desecante, una rueda entálpica, y una unidad de enfriamiento convencional. El coeficiente de desempeño de este sistema COP tiene un rango de 2.84 a 3.51, valores que se corresponden con los reportados en la bibliografía para sistemas similares. Se obtuvieron 2 modelos que permiten predecir el comportamiento del aire en el sistema de enfriamiento y obtener los valores de temperatura y humedad en el local objeto de estudio, todos con errores máximos menores del 5%.
... Considerando los cinco parámetros descritos, se llevó a cabo un estudio de experimentos factorial fraccionado 2 k-1 . Los ensayos realizados valoran las distintas combinaciones de cada uno de los niveles de los factores, algo que permite evaluar la respuesta del algoritmo cuando varía el nivel del factor (Montgomery, 2002). Los niveles asignados a cada uno de los parámetros de la metaheurística híbrida pueden consultarse en la tabla 5. La tabla 6, muestra el diseño de experimentos, junto con el valor medio del coste y el coste computacional asociado a la obtención de cada uno de los diseños óptimos. ...
Los marcos articulados prefabricados de hormigón armado son una estructura de uso común en las redes de carreteras. Los avances en las técnicas de optimización permiten mejorar el proceso de diseño tradicional, consiguiendo minimizar factores como el coste final de la estructura. El estudio llevó a cabo la optimización económica de un marco articulado prefabricado de hormigón armado mediante la técnica metaheurística híbrida de recocido simulado con operador de mutación. Los parámetros del algoritmo fueron calibrados mediante un diseño de experimentos factorial, consiguiendo que el algoritmo tuviera un muy buen rendimiento. Tras su calibración, la metaheurística híbrida fue aplicada, consiguiendo diseños con costes finales reducidos. Finalmente, se mencionan una serie de características principales de los marcos óptimos, pudiendo destacar diseños esbeltos con densidades de armado elevadas. Los resultados sitúan la tipología estructural considerada como una alternativa especialmente interesante frente a las estructuras ejecutadas in situ.
... Data normality tests were performed. In the cases in which this condition was not fulfilled, we continued with the ANOVA because this analysis was robust to the violation of this assumption, that is, it did not alter the Type I Error (Montgomery, 1991;García-Berthou et al., 2009). Homoscedasticity was also assessed using the Levene test; if this condition was met, the post hoc analysis was completed with the least significant difference (LSD) test; otherwise, a transformation of the data was made and, if the lack of homoscedasticity persisted, the interpretation was made using the Games-Howell test (SPSS, 2006). ...
Aim of study: To compare the diversity and biomass of logged forests, with different ages after harvesting and the risk of their degradation to liana forests.
Area of study: We studied 18 plots at the central zone of the Imataca Forest Reserve (Guayana shield), Venezuela.
Material and methods: We used 1-ha plots, to measure individuals with dbh > 10 cm in control plots (0 years) and in logged plots with 3, 9, 12, 15 and 18 years after logging. The main variables evaluated were enlarge importance index (EII), richness (R), Shannon-Weaner index (H´), Alpha Fischer (α), basal area for commercial species (BA_comm), above-ground carbon (C) and lianas abundance at the understory (Lianas_%Au).
Main results: Diversity variables (R: 62-77 spp ha-1, p: 0.117-0.838; H´: 2.8-3.4, p: 0.181-0.677; α: 18.6-25.4, p: 0.293-0.922) and biomass (89.6-180.2 MgC ha-1, p: 0.171-0.895) did not have significant differences between control and most of the logged plots. Only the 18 years-old forests had statistically higher values of diversity (R: 81-94 spp ha-1, p: 0.000; H´: 3.8-3.9, p: 0.000; α: 26.8-31.7, p: 0.000), perhaps due to a high impact skidding operation. Commercial species were not recovering after logging.
Research highlights: Forest management can be viable in this area, but it requires reduced impact logging techniques and better silvicultural systems to guarantee future harvest of high value commercial timber.
... Analysis of variance was used to measure the magnitude of the effects of the factors on the response variables. The adjusted determination coefficient (R 2 Adj ) was used to measure the proportion of the total observed variability described by the model [33]. The factorial model was used to build the response variable surfaces and find the maximal value of responses by using Design-Expert software (version 11.1.2, ...
Herein, a methodology for 3D printing of activated carbon powders in monolithic form using direct ink writing and carboxymethylcellulose as binder is reported, along with the effect on their physicochemical and mechanical properties. Monoliths with different wall diameters (0.42, 0.62, and 0.82 mm) and infill percentages (30, 50, and 70%) were designed and manufactured. The monoliths were heat-treated under a nitrogen atmosphere at 400 °C and 600 °C to remove the volatile material from the binder used. The monoliths showed a decrease in dimension of less than 8% from their designed values, attributed to the volatilization of water present in the binder solution in the drying and heat-treatment process. The printed monoliths presented pore distributions similar to those of their powdered counterparts. The isoelectric point of the monoliths increased relative to that of the powdered material and became more basic as the heat treatment temperature increased. The monoliths presented compressive strengths from 0.58 to 3.53 MPa. The analysis of variance of the compressive strength showed that the wall diameter and temperature are the most influential treatment parameters. The printed monoliths exhibited similar CO2 adsorption capacity (0.37 mol Kg⁻¹ at 10 kPa and 25°C) compared to the powder precursor. Fixed bed tests demonstrated that the 3D printed monoliths enhanced the mass transfer compared to conventionally extruded pelletswith same wall diameter.
... The experimental sets (Table 2) were simulated with the neural network considering environmental conditions of the days of maximum (C1) and minimum solar radiation (C2) assessed during the development of the experiments. The principal effects of the factors (Montgomery, 2004): plate depth, plate material, the thickness of the absorber plates, and inlet airspeed were estimated. The average efficiencies were obtained from the simulations of the experimental environmental data with the parameter input in the developed neural network. ...
... The effects of site (2), season (4) and species as well as their double (site × season, site × species and season × species) and triple (site × season × species) interactions on chemical analyses, in vitro gas production parameters and digestibility data were determined via analysis of variance using a completely randomized design with a factorial arrangement (Montgomery 2004 While there was marked variation between species at all sites in most seasons, overall C. pallida showed consistently lowest OM concentration, followed by G. angustifolium, with the remaining species higher. On the other hand, C. pallida showed the highest CP concentration of all species in summer and autumn. ...
This study aimed to determine seasonal chemical composition, metabolizable energy (ME) concentration, in vitro gas production patterns, in vitro organic matter digestibility (IVOMD) and in vitro true organic matter digestibility (IVTOMD) of foliage from 5 native shrub species (Celtis pallida, Croton suaveolens, Forestiera angustifolia, Guaiacum angustifolium and Parkinsonia aculeata) growing in semi-arid areas of northeastern Mexico between July 2018 and June 2019 at 2 research sites. Crude protein (CP) concentrations (>13.2% DM) found in leaf material should meet or exceed the requirements for maintenance of small ruminants; C. pallida provided the highest CP% (20.8‒29.3%). While CP% varied with season and site, species had a greater effect than either of those factors overall. ME concentrations ranged between 1.2 and 2.0 Mcal/kg DM. Neutral detergent fiber and acid detergent fiber concentrations ranged from 29.8 to 51.7% DM and 9.8 to 33.0% DM, respectively. Data obtained for IVOMD (34.5‒58.8%) and IVTOMD (64.1‒88.7%) demonstrate the high nutritive potential of leaf of browse species under study, especially C. pallida, as useful feed supplements for small ruminants in the semi-arid region of northeastern Mexico. Further studies could examine DM yields of browse from the various species, acceptance by small ruminants and their sustainability under regular defoliation under grazing.
... Se utilizó el diseño central compuesto rotacional (DCCR) (Montgomery, 2004). El Bebida instantánea a partir de granos tostados DCCR fue de 2 2 puntos del diseño factorial, con 4 puntos axiales y 3 puntos centrales, sumando un total de 11 tratamientos para cada grano tostado (Cuadro 2). ...
Los granos en zonas altoandinas poseen diversos compuestos nutricionales; no obstante, debido a sus cualidades sensoriales, sólo son consumidos en fresco o deshidratados. Una alternativa de procesamiento es el tostado de los granos para la obtención de bebidas. El objetivo del estudio fue evaluar el tiempo y temperatura de tostado sobre la solubilidad y el diferencial de color (ΔE) de los granos de arveja, cebada y haba, a fin de determinar los parámetros óptimos de tostado, así como, diseñar una mezcla óptima de granos para la obtención de una bebida instantánea. En una primera etapa se utilizó un diseño central compuesto rotacional para la optimización del proceso de tostado a partir de la solubilidad y el ΔE. En una segunda etapa, se aplicó un diseño simplex-centroide para determinar la mezcla óptima de harina tostada para la bebida instantánea. Los granos de cebada tostada presentaron la mayor solubilidad, mientras que el ΔE más alto se obtuvo de los granos de arveja tostada. La temperatura de tostado presentó un efecto significativo (P≤0,05) sobre la solubilidad de la cebada y arveja, mientras que el tiempo y la temperatura exhibieron un efecto significativo sobre el ΔE de los tres tipos de grano. Los parámetros óptimos de tostado fueron distintos para cada grano. Las bebidas con altos porcentajes de harina de haba y cebada, y bajos porcentajes de harina de arveja tuvieron la mayor aceptabilidad. Se concluye que a partir de granos cultivados en zonas andinas se pueden obtener bebidas instantáneas con alta aceptabilidad.
... We used end-to-end testing, featuring a VLC video server (source node) and VLC client (destination node [34]) and a scenario made up using drone swarms. It includes elements related to the swarm characteristics, control unit devices and managing the information and data obtained on each of the missions (See Figure 1). ...
In this work, a group of mechanisms are exposed to provide quality of experience in flying ad hoc networks using a swarm of drones in a natural disaster service. End-to-end video traffic was analyzed. The metrics used to experimentally measure QoE/QoS are: delay, jitter and packet loss. The experience quality was evaluated before the disaster (C00), at the moment (B00) and after the disaster (I00). The methodology used to perform the design was experimental, and the NS simulator was used to evaluate the behavior of the swarm of drones connected through a flying ad hoc network. To perform data analysis, treatment and repetitions related to video traffic, the response surface methodology (MSR) was used, which is a set of mathematical techniques in order to optimize the obtained responses. The composite core design (DCC) was also used as it was the best fit to our experiment due to its flexibility. Since the quality of the experience was evaluated at three moments, the quality of services was also analyzed with three metrics. The main contributions of the research are a mathematical model of the quality of the experience based on the quality of the service; an experiment design using the end-to-end NS simulator; a methodology for the mathematical and statistical analysis of the data obtained; an algorithm that allows, from service quality metrics, to obtain the quality of the experience for end-to-end video traffic; and a proposal for future work for data analysis in a physical environment and applied to the environmental sector.
... La presente investigación empleó un diseño experimental (Douglas, 1992;Gutiérrez, 2004) ...
El presente trabajo tuvo por objetivo optimizar la recuperación de un pre-concentrado de oro a partir de los minerales sulfurados en el proceso de flotación determinando los parámetros de porcentaje de sólidos, dosificación de reactivos y tiempo de flotación, se ha procedido a realizar un bloque de pruebas de acuerdo con un diseño experimental estadístico el diseño factorial 23 para 3 factores o variables a dos niveles, con 11 corridas, incluido 3 puntos centrales, para la realización de cada uno de los experimentos. Durante el procedimiento se ha trabajado con un mineral sulfurado que contiene pirita (FeS2) calcopirita (FeCuS2), blenda o esfalerita (ZnS), galena (PbS). Con una ley promedio de cabeza (oro) de 10g/TM. Para la etapa de molienda el mineral se ha molido a una granulometría de 65% -200 mallas. Por lo que también se determinó que el tiempo óptimo de molienda para 65% -200 mallas es de 21,65 minutos. Se concluye que es posible optimizar el proceso de flotación con una recuperación de 76,96% a comparación con lo que se trabaja en planta con una recuperación de 70,08%, la prueba que ha dado los mejores resultados es la prueba Nº6 que logró obtener una ley de 58,45 g/TM de oro en el concentrado y 2,59 g/TM de oro en el relave; y una recuperación de 76,96% de oro, a su vez para obtener esta recuperación el % solidos es de 35%, colector A-238 de 50g/TM, tiempo de flotación 10 minutos. Se ha determinado que las variables más importantes que inciden en el proceso son: % de sólidos y dosificación Del colector Aerofloat-238.
... The Kruskal-Wallis non-parametric test [37] was used to analyze differences in the means of variables with non-normal distributions. Complementarily, the Bonferroni and Games-Howell tests were applied to determine, more concretely, the differences between the four groups [38]. ...
A country’s global competitiveness is a fundamental element that facilitates the understanding of why some countries generate more wealth than others, as well as better sources of income in a sustainable manner. With globalization and market integration, governments are reviewing the current values of economic, business, social, and environmental variables that define multidimensional competitiveness indices. Central American countries face difficult economic situations with challenging political and social ramifications. This study presents a comparative analysis of the competitiveness of Central American countries in a globalized environment before the COVID-19 pandemic. For this purpose, multivariate statistical analysis and Cluster analysis have been applied to data from the World Economic Forum (WEF) Global Competitiveness Index 2018, contrasting it with the publication of the same index for 2019. This methodology allows to rank countries with similar levels of competitiveness and shows the relative position of each country about countries belonging to the same group and countries belonging to other groups with different levels of competitiveness. The results show differences in competitiveness at the country level in 12 variables or composite indicators of the Global Competitiveness Index, the most important being Macroeconomic Stability, IT Adoption, and Infrastructure, with the most significant differences between countries. This result contributes to the current policy discussion on measures to achieve sustainable competitiveness of Central American economies.
... The Gage R & R method tells us that there is a respectability of 92.31% between operators, consistency and it maintains its criteria the same among the tests that the same operator does. Procedure recommended by Montgomery (1991). Using the Minitab as a statistical tool, the corresponding run was made with the variables described above with a run of 24 combinations and 1 replicate. ...
... Con los datos recabados se inició con un análisis estadístico descriptivo y, posteriormente, se realizó un análisis de varianza (Anova) para un modelo de bloques aleatorizados para determinar la existencia de diferencias (p < 0.05) en las medias de las dimensiones de la variable economía circular, así como entre las dimensiones de la variable ventaja competitiva. Como complemento, se aplicó la prueba de Tukey para realizar comparaciones múltiples entre las medias con un nivel de significancia del 95% (Montgomery, 2014). Los resultados fueron analizados empleando los programas estadísticos Minitab 17 ® e IBM SPSS Statistics 21®. ...
Ante la crisis ambiental, las empresas requieren modelos de producción que mitiguen el cambio climático y representen una ventaja competitiva, siendo la economía circular una alternativa. El objetivo de este estudio fue determinar si los principios de economía circular: preservar y mejorar el capital natural, optimizar el rendimiento de los recursos y promover la efectividad del sistema representan una ventaja competitiva, tomando como objeto de estudio las pequeñas y medianas empresas (Pyme) del sector textil de Tlaxcala, México. La metodología consistió en realizar un diagnóstico sobre la percepción de las variables. Posteriormente, se realizó un análisis descriptivo y de varianza (Anova), una prueba Tukey, un análisis de correlación y un análisis de regresión para determinar su significancia y relación. Los resultados revelaron que los principios de economía circular permitirán a la Pyme un desempeño superior con respecto a la competencia, haciéndola diferente y bajando sus costos. Se concluye que la economía circular sí puede impactar en el cuidado ambiental y en la competitividad.
... To improve the performance of pectin in the acid hydrolysis stage, a Box-Behnken design (Montgomery, 2013) with three factors was used; the first factor was temperature, with levels of 70, 80 and 90 °C. The second factor was pH, with levels of 1.5, 2 and 3. ...
Coconut cake is a by-product that results from extractions of coconut milk and oil, which has been reported to have around 20% protein. The state of Guerrero is positioned as the leading coconut producer in Mexico; however, there is a lack of diversification of coconut-based products. Therefore, the present work focused on the isolation and characterization of the storage proteins of the coconut cake. The methodology used was the following: The endosperm of C. nucifera L. was cut into cubes, ground, and strained to later dehydrated (65±3 °C) and finally defatted. Proteins were fractionated, and soluble protein was quantified by the Bradford method. SDS-PAGE monitored the protein profile.
The protein fractions were analyzed for techno-functional characteristics as surface hydrophobicity, emulsifying activity index, and emulsifying stability index. The results exhibited that glutelins were the predominant proteins (68.65%), followed by globulins (28.42%). In the protein profile, cocosin was identified, which is the major protein of the coconut endosperm. The highest and lowest solubility of coconut protein was found at pH 8 to 12 and pH 4 to 6, respectively. Globulins showed greater surface hydrophobicity (304,574 ± 33,778). For the emulsion stability, no statistical differences were
observed. Albumin and glutelins showed the highest emulsifying activity (11.52 ± 0.42 and 13.33 ± 1.57 m2/g, respectively). In conclusion, the reserve proteins presented techno-functional properties.
... The optimization process was designed through the construction of a second-order model with central composite designs (CCD) [47,48]. The full 2 k factorial design type model for lipopeptide optimization was designed based on the agitation and aeration factors, where k is the number of factors. ...
Halophilic microorganisms are potentially capable as platforms to produce low-cost biosurfactants. However, the robustness of bioprocesses is still a challenge and, therefore, it is essential to understand the effects of microbiological culture conditions through bioreactor engineering. Based on a design of experiments (DOE) and a response surface methodology (RSM) tailored and taken from the literature, the present work focuses on the evaluation of a composite central design (CCD) under batch cultures in stirred-tank bioreactors with the halophilic bacteria Salibacterium sp. 4CTb in order to determine the operative conditions that favor mass transfer and optimize the production of a lipopeptide. The results obtained showed profiles highlighting the most favorable culture conditions, which lead to an emulsification index (E24%) higher than 70%. Moreover, through the behavior of dissolved oxygen (DO), it was possible to experimentally evaluate the higher volumetric coefficient of mass transfer in the presence of lipopeptide (kLa = 31 1/h) as a key criterion for the synthesis of the biosurfactant on further cell expansion.
... The minimum and maximum values of temperature were fixed at 126 • C and 180 • C, respectively; whereas the minimum and maximum values of time were established at 7 and 18 h, respectively, according to the values reported in the literature [18,21]. The number of experimental runs (N) was obtained using the CCD model, as follows: where K stands for the number of natural variables, 2 K represents the factorial points (maximum and minimum of each variable), 2K is the axial or star points (new maximum and minimum extremes of each factor), and n c represents the number of central points [42]. According to this DoE, eleven experimental runs were determined and organized in random order, as shown in Table 1. ...
Recently, bismuth oxyiodide (BiOI) is an attractive semiconductor to use in heterogeneous photocatalysis processes. Unfortunately, BiOI individually shows limited photocatalytic efficiency, instability, and a quick recombination of electron/holes. Considering the practical application of this semiconductor, some studies show that synthetic zeolites provide good support for this photocatalyst. This support material permits a better photocatalytic efficiency because it prevents the quick recombination of photogenerated pairs. However, the optimal conditions (time and temperature) to obtain composites (BiOI/ synthetic zeolite) with high photocatalytic efficiency using a coprecipitation-solvothermal growth method have not yet been reported. In this study, a response surface methodology (RSM) based on a central composite design (CCD) was applied to optimize the synthesis conditions of BiOI/mordenite composites. For this purpose, eleven BiOI/mordenite composites were synthesized using a combined coprecipitation-solvothermal method under different time and temperature conditions. The photocatalytic activities of the synthesized composites were evaluated after 20 min of photocatalytic oxidation of caffeic acid, a typical organic pollutant found in agro-industrial wastewater. Moreover, BiOI/mordenite composites with the highest and lowest photocatalytic activity were physically and chemically characterized using nitrogen adsorption isotherms, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and diffuse reflectance spectroscopy (DRS). The optimal synthesis conditions prove to be 187 °C and 9 h. In addition, the changes applied to the experimental conditions led to surface property modifications that influenced the photocatalytic degradation efficiency of the BiOI/mordenite composite toward caffeic acid photodegradation.
Teacher job satisfaction is an important aspect of academic performance, student retention, and teacher retention. We propose to determine the predictive model of job satisfaction of basic education teachers using machine learning techniques. The original data set consisted of 15,087 instances and 942 attributes from the national survey of teachers from public and private educational institutions of regular basic education (ENDO-2018) carried out by the Ministry of Education of Peru. We used the ANOVA F-test filter and the Chi-Square filter as feature selection techniques. In the modeling phase, the logistic regression algorithms, Gradient Boosting, Random Forest, XGBoost and Decision Trees-CART were used. Among the algorithms evaluated, XGBoost and Random Forest stand out, obtaining similar results in 4 of the 8 metrics evaluated, these are: balanced accuracy of 74%, sensitivity of 74%, F1-Score of 0.48 and negative predictive value of 0.94. However, in terms of the area under the ROC curve, XGBoost scores 0.83, while Random Forest scores 0.82. These algorithms also obtain the highest true-positive values (479 instances) and lowest false-negative values (168 instances) in the confusion matrix. Economic income, satisfaction with life, self-esteem, teaching activity, relationship with the director, perception of living conditions, family relationships; health problems related to depression and satisfaction with the relationship with colleagues turned out to be the most important predictors of job satisfaction in basic education teachers.
Este artículo científico presenta las unidades de análisis resultantes que permitió la Construcción del Perfil Productivo del Municipio de Convención. Dejando estructurado estrategias que impliquen oportunidades en el mercado laboral y cimiente rutas de inclusión a población víctima, desplazamiento y extrema pobreza al desarrollo económico y actividad laboral. La investigación logró revelar la producción e panela como una actividad que si se direcciona de la forma correcta logrará un desararrollo socioeconómico del municipio. Esto debido a las características históricas del cultivo, el cual ha hecho presencia desde principios del siglo XX, además, el momento de apertura económica ha permitido que se abran nuevos mercados que deben ser aprovechados por os productores de panela. Sin embargo, en la actualidad la certificación que emite el INVIMA (Resolución 779 del 2006), solo es cumplida por menos del 5,0% de los trapiches en el municipio lo cual no permite aprovechar la coyuntura económica, dado que el mercado extranjero es exigente en materia de calidad y procesos productivos de los artículos comprados. Asi mismo, la investigación está ajustada en el marco del proceso de posconflicto que está viviendo Colombia, dado que el desarrollo productivo en el marco de la legalidad, permitirá que los habitantes abandonen los cultivos ilícitos, el cual es utilizado como alternativa de generación de ingresos.
Se evaluaron los efectos de la temperatura de extracción (40-70 °C), el tiempo de extracción (60-400 min) y la concentración de ácido cítrico (0.1-0.9%) sobre las respuestas de fuerza de gel (g) y rendimiento de proteína (%). Las condiciones óptimas de extracción fueron 56.8 °C, 331 min y 0.26% de ácido cítrico. Los valores experimentales de las respuestas fueron 387 ± 4.5 g de fuerza de gel y 20.4 ± 0.08% de rendimiento de proteína. La gelatina obtenida fue caracterizada y los resultados mostraron un alto contenido de proteína (88.3%) y bajo contenido de cenizas (1.0%). El principal aminoácido fue la glicina (20.9%) y el contenido de iminoácidos (prolina e hidroxiprolina) fue de 18.7%, mientras que el contenido de aminoácidos esenciales fue de 22.35 g/100 g de proteína. Los valores de los puntos de gelificación y fusión fueron 17.6 y 25.6 °C, respectivamente. La viscosidad a 60 °C fue de 11.0 cP y el valor de pH fue de 4.9. La gelatina de piel de mahi-mahi cumple con los requisitos fisicoquímicos exigidos para una gelatina comestible.
The effect of the variables temperature, time and amount of enzyme on the degree of hydrolysis and the level of bitterness of the hydrolysates obtained from anchovy (Engraulis ringens) was examined. Anchovy without head, skin, tail, and viscera, is treated in a two-stage enzymatic hydrolysis process by using the response surface method. In the first stage, the Corolase 8000 enzyme is assessed by optimizing the process (60.1°C, 93.4 minutes, and 1.68% enzyme), maximizing the degree of hydrolysis up to a value of 12.8%. In the second stage, the enzyme Corolase 7089 is applied, maximizing the degree of hydrolysis (14.8%) while minimizing bitterness (3.8) by conducting the process at 49.1°C, for 54.3 min, with 0.472% Corolase 7089 enzyme. Mathematical models obtained can be applied in the standardization of a process if the degree of hydrolysis and the level of bitterness that best suits a specific purpose are established.
El proyecto es multidisciplinario, pues convergen las temáticas de Ingeniería de Sistemas, la Comunicación Social y la Estadística. Y también es interinstitucional, dado que unieron fuerzas el programa de Comunicación Social-Periodismo y el área de Estadística de la Facultad de Ciencias Básicas de la Universidad Autónoma de Occidente, así como los grupos de investigación LIDIS de la Universidad de San Buenaventura-Cali y COMBA I+D de la Universidad Santiago de Cali.
El uso de fibras de origen natural como refuerzo en Materiales Compuestos (MC), ha venido tomando fuerza en los últimos años. En este caso se tiene un MC con matriz de polipropileno (PP) reciclado, proveniente de tapas de diferentes envases de productos de consumo diario. Para el refuerzo se eligió usar fibra natural de Guadua angustifolia y polvo de cerámica tenaz. La fibra de Guadua se obtuvo en condiciones de secado e inmunizado con el fin de reducir su humedad y evitar la aparición de hongos y líquenes. El polvo de cerámica tenaz también es un material reciclado, obtenido de pisos de cerámica que se trituraron y pulverizaron previo a la inserción al MC. Las proporciones usadas para fabricar las probetas del MC fueron: una con 100% de PP y otras con diferente composición del MC, donde la matriz de PP se mantuvo con el 60%, y se combinaron los materiales de refuerzo, para obtener los siguientes grupos de especímenes, uno con 30% fibra y 10% cerámica, otro con 33% fibra y 7% cerámica y un último con 35% fibra y 5% cerámica. Una vez obtenidas las probetas del MC, se realizaron los ensayos mecánicos, de tensión según la norma ASTM 638D para polímeros, y de flexión con la norma ASTM 970D para plásticos reforzados. Se analizaron los resultados obtenidos, mediante análisis de varianza (ANOVA), usando un nivel de significancia de α = 0.05 y un enfoque de valor P para la verificación de la hipótesis nula. El análisis estadístico se realizó mediante el software Minitab 18, encontrando como resultado más importante, que el módulo de elasticidad a tensión del PP aumentó en un 53,49%, al adicionarle Guadua en un 35% y cerámica en un 5%.
One of the main problems in using the flux-cored arc welding (FCAW) process in underwater conditions is the adequate control of the welding parameters that determine the stability of the arc and quality of the joints obtained. Thereby, the objective of this research work is to evaluate the superficial porosity variation in welding bead made on ASTM A36 steel plates using the underwater wet welding FCAW-S process. Commercial wire (AWS E71T-GS) was used to perform wet welds in simulated conditions of laboratory in a container with 30 cm of fresh water column. The configuration of the experimental tests was carried out using a central composite design and response surface methodology (RSM) analysis, obtaining an experimental matrix of 17 underwater wet welding tests. The input parameters and variation levels included wire feed speed (250–450 ipm), arc voltage (22–26 V) and welding speed (3–10 mm/s), whilst the superficial porosity was selected as the output variable of the RSM. All the samples presenting superficial porosity derived the difficulty in controlling the stability of the arc in a wet environment. From the results obtained it was possible to establish an empirical mathematical model for superficial porosity as a function of welding parameters in underwater wet welding performed with FCAW-S process. In general, it was observed that the highest porosity occurs for high values of voltage and welding speeds. The lowest levels to superficial porosity were obtained with the following parameters setting: welding speed at 3.0 to 4.4 mm/s, arc voltage at 23 to 25 V and wire feed speed between 350 and 400 ipm.Graphical abstract
Different initiatives have been implemented to improve air quality in large cities, such as encouraging travel by sustainable modes of transport, promoting electro-mobility, or the car-free day. However, to date, we have not found statistics that indicate to what extent the concentration levels of particulate matter PM2.5, PM10 and nitrogen oxides (NOx) pollutants decrease as a result of public policy. We used official data from the Chilean Government’s national air quality information system (SINCA) for the Santiago metropolitan region and estimated the impact of the confinement by COVID-19 on the ambient concentration average values of NOx gases and particulate matter PM2.5 and PM10, which are the main air pollutants produced by the transport sector after CO2. We found that in general there are significant differences between the average levels of gas emissions for 2020 compared to 2019. In particular, we found that, for the months of total confinement May-July, the monthly average levels decreased between 7% and 19% for particulate matter PM2.5, between 18% and 50% for PM10 and between 34% and 48% for NOx. With the return to the new normality, these improvements in ambient concentration levels may be affected by the increase in private transport trips, due to the reluctance of citizens to return to mass public transport. Our results, therefore, represent the maximum impact that can be expected in reducing ambient concentration levels in the city of Santiago of Chile when a mobility reduction of gasoline vehicles is implemented. The reduction of PM2.5, PM10 and NOx was no more than 7%, 18% and 34%, respectively. The average concentration of PM2.5 decreased by 7–19% compared to previous years. The average concentration of PM10 decreased by 18% and 50% compared to previous years. Concentrating commuting on public transport would help reduce levels of PM10 and PM2.5.
El gladiolo como flor de corte ocupa el tercer lugar dentro de los ornamentales florícolas en cinco estados productivos de México. Siendo una flor muy aceptada por sus colores llamativos, presenta una vida en florero muy corta debido a la producción endógena de etileno, hormona que induce la senescencia y que se sintetiza en los órganos florares en su proceso de maduración. Actualmente se pretende usar sustancias que prolonguen la vida de las flores y que sean inocuos al usuario y al ambiente. De esta manera el uso de extractos vegetales puede ser una alternativa viable. La utilización del extracto de hoja de vid silvestre, del que se ha demostrado la presencia de algunos compuestos fenólicos, entre otros el resveratrol, podría aumentar la vida postcosecha. El objetivo de esta investigación fue utilizar diferentes dosis de hoja de vid silvestre (0, 0.5, 1.0 y 5.0 g l-1), con un tiempo pulso de 12 h, en una solución hidratante, siendo 0.5 g l-1 la dosis que mayor absorción de agua presentó al segundo día después de corte (P<0.05). Esta misma dosis fue estadísticamente significativa (P<0.05) para la variable cinética de peso, alcanzando el mayor porcentaje, del día dos al cuatro después de cosecha. De igual manera, 0.5 g l-1 mostró diferencia estadística (P<0.05) en el día diez después de corte, para el color a* y cromaticidad. Sin embargo la dosis de 5.0 g l-1 fue la que proporcionó mayor valor L* (P<0.05), evitando el obscurecimiento de la flor.
This article shows the results obtained by analyzing an emerging technology to produce bioethanol from coffee mucilage under sustainable development constraints. The investigation showed that the addition of an antibiotic is important to avoid contamination of the mucilage related to the presence of bacteria since these microorganisms can eat the sugars present in the biomass for their metabolism. On the other hand, for the conversion of cellulose and hemicellulose into simple reducing sugars present in coffee mucilage, the addition of the enzyme pectinase was necessary. The ANOVA analysis showed that the cellulase dose is the most significant factor in the hydrolysis process. The adequate doses of enzymes for the enzymatic hydrolysis process of coffee mucilage were obtained by the response surface method, finding an optimal value of 0,352 mL and 0,134 mL of cellulase and hemicellulase, respectively, per 100 mL of mucilage. From the logistics approach, the supply of coffee mucilage to a second-generation ethanol pilot plant with an installed capacity of 15.000 liters of mucilage per week was considered. Ideally, the pulping process must be carried out mechanically without water, ensuring a mucilage Brix content between 16 and 21, which would favor an ethanol yield close to 8% (v/v) in the must. A potential production of 4,137 liters of ethanol could be achieved with a total logistics cost of USD 305 if the available mucilage is collected. A potential reduction of 7,650 kg of carbon dioxide is possible if the ethanol produced is used to replace the same amount of gasoline in the transportation industry.
This research aimed to elaborate a panettone with wheat flour and quinoa flour. By using the Response Surface Methodology (RSM), the effect of quinoa flour (10% and 30%), powder gluten (2% and 4.8%), lecithin (0.2% y 0.5%), and water (35% and 50%) was studied through the application of a factorial design 24 that allowed to identify that lecithin was a non‐significant factor (p>0.05).A Central Composite Rotational Design (CCRD) was used to get polynomial models of second order, for the variable responses: specific volume, toughness, cohesiveness, and gumminess, which were simultaneously optimized, based on the maximization of desirability functions (0.94). The optimal formulation contained 26.23% quinoa flour, 4.8% gluten, 50% water and stood out for its low‐fat content: 7.6%. With the optimized formulation, it is possible to produce panettones with a significant percentage of quinoa flour. Thus, this formulation becomes an alternative for the elaboration of low‐fat and nutritious products.
El clima es el factor principal que domina el entorno de producción en el sector agrícola. El cambio climático se ha manifestado a través de un aumento en las temperaturas superficiales promedio globales de aproximadamente 0.7 °C en el siglo XX. Las modificaciones en la composición de la atmósfera producen cambios en la reflexión y absorción de la energía solar y como resultado se obtiene un clima diferente.
En el centro geográfico de la provincia de Buenos Aires desde la década de 1960 se ha intensificado la ocurrencia de eventos extremos de los fenómenos meteorológicos, como consecuencia del cambio climático.
Las heladas son una de las adversidades climáticas que más afectan la producción, tanto en explotaciones intensivas como extensivas. Por esto resulta de fundamental importancia el conocimiento de la frecuencia, estacionalidad e intensidad de las heladas de una zona, en el clima actual y en el del futuro.
Se utilizó la base de datos agrometeorológicos diarios del período 1989-2018 de la estación principal del Centro Regional de Agrometeorología de la Facultad de Agronomía-UNCPBA, Azul provincia de Buenos Aires, los que se disturbaron utilizando
el programa DSSAT- Perturb. Se seleccionaron tres posibles escenarios o trayectorias de concentración de gases de efecto invernadero donde cada uno corresponde al forzamiento radiativo proyectado para final del siglo XXI: 2.6, 6 y 8.5 W/m2. El escenario de 2.6 W/m2 es en el que menos aumenta la temperatura, el de 8.5 W/m2 el que más. Los datos climáticos futuros se derivaron del conjunto de cuarenta modelos climáticos globales para analizar el clima futuro (2050 y 2100).
La caracterización de heladas se realizó mediante el cómputo de las variables siguientes: fecha media de primera y última helada, período medio con y sin heladas, intensidad y frecuencia de heladas meteorológicas (temperaturas iguales o menores a 0 ºC en casilla meteorológica a 1,5 m de altura sobre el suelo).
Plastic pollution is one of the most serious environmental problems of this century because most plastics are single-use, and once their useful life is over, they become pollutants, since their decomposition takes approximately 100–400 years. The objective of this research is to evaluate the efficacy of low-density polyethylene (LDPE) biodegradation by G. mellonella in the district of Pangoa, Junín, Peru. For the development of the study, the G. mellonella was conditioned in three groups of beekeeping residues (beeswax, balanced diet, and wheat bran); after the conditioning stage, the biodegradation treatment was developed, which consisted of placing the G. mellonella in terrariums with the LDPE, the treatments were carried out at three different times (24, 36, and 48 h). To evaluate the efficacy of biodegradation, two analyses were taken into account: the Raman analysis of the low-density polyethylene samples and the weight reduction of the treated LDPE. The results of the Raman analysis indicated that the best treatment was the one applied with G. mellonella conditioned with beeswax, obtaining a wavelength intensity of 0.45 μ.a., while the weight reduction of the LDPE indicated that the best results were given at 36 h and conditioned with beeswax with a reduction of 236.3 mg. In conclusion, the use of G. mellonella for the biodegradation of low-density polyethylene is effective when it is conditioned with beeswax and the treatment is carried out at 36 h.
La lúcuma (Pouteria lucuma) fue procesada a escala de laboratorio para la obtención de snacks por secado convectivo, alcanzando un rendimiento promedio de 71.12%; la pulpa de lúcuma fue amasada adicionando las mezclas de aditivos conformados por maltodextrina, ácido ascórbico y dióxido de silicio. Dichas muestras fueron deshidratadas para obtener la textura de un snack, utilizando secado convectivo a dos niveles de una variable del proceso 50° C y 70° C para determinar la(s) muestra(s) donde se obtuvo la mejor mezcla con mayor cantidad de carotenoides. Estas muestras fueron comparadas con la muestra sin aditivos y con la liofilizada. De un total de 20 mezclas de aditivos a dos niveles de temperatura, se cuantificaron los carotenoides de las muestras con mezcla de aditivos y la liofilizada, mediante el método espectrofotométrico se obtuvo que la mejor mezcla fue la conformada por 0% Maltodextrina, 100% Ácido ascórbico y 0% de dióxido de silicio con la temperatura de 50°C con una cantidad de carotenoides totales de 0.2753 ± 0.031 mg β- caroteno/g BS.
p>La función del Sistema Masticatorio se encuentra relacionada entre otros aspectos con las características de la configuración oclusal. Se han descrito a través de los años diferentes concepciones de la oclusión, hasta llegar a los conceptos de Oclusión Funcional actualmente utilizados. Se han establecido características comunes de oclusiones consideradas ideales o normales, sin embargo en la actualidad diversos autores concluyen que las características oclusales son específicas de cada individuo. El objetivo de este estudio fue determinar el relieve coronal vestibular de ambas arcadas a través de la medición de la rotación de las coronas dentales presentes en una población mexicana sin tratamiento de ortodoncia con una oclusión considerada normal. En 110 modelos de estudio se midieron las rotaciones de las coronas dentales. Se utilizó un aparato y un aditamento que permiten la medición de superficies dentales empleando un rayo láser. Los resultados muestran un patrón similar en las rotaciones entre el lado derecho e izquierdo de una misma región (mandibular y maxilar). Todas las rotaciones promedio de los dientes de la mandíbula midieron entre -1° y 1°. En cambio, la rotación promedio de los dientes maxilares fluctuó entre -2° y 8.5°. En ambas regiones, el central, el lateral y el canino tuvieron una rotación promedio negativa a diferencia de los premolares y molares que presentaron una rotación promedio positiva. Los molares superiores e inferiores presentaron mayor desviación estándar. Se concluye que debido a la variación observada en la rotación coronal no es adecuado estandarizar sus valores para realizar los tratamientos de ortodoncia, por lo que la utilización de aparatología con prescripción individualizada es más conveniente.</p
Resumen La agricultura urbana promueve el cultivo de hortalizas en la ciudad; sin embargo, se requiere germinar semillas para obtener plántulas que permitan iniciar con esta práctica una forma sostenible, sustentable y práctica. Objetivo. Evaluar el porcentaje de germinación de dos variedades de lechuga (Lactuca sativa), más específicamente del tipo milanesa y conconina, para determinar si existe diferencia significativa en su germinación para la obtención de plántulas. Materiales y métodos. Se realizó un diseño factorial 2 2 , teniendo en cuenta las combinaciones de variedad y luminosidad; se planteó un modelo estadístico, para describir su comportamiento. Resultados. El factor de mayor influencia en el porcentaje de germinación es la variedad; los mejores resultados se encontraron la variedad milanesa bajo condiciones de luz. Conclusiones. La variedad milanesa es una buena opción para generar plántulas y, bajo condiciones de luz, se puede obtener un porcentaje de germinación del 92.5 %, valor superior al reportado por el productor. Palabras clave: germinación, lechuga, diseño factorial, sustentabilidad, huertos urbanos. Abstract Introduction: Urban agriculture promotes the cultivation of vegetables in the city, however seeds are required to germinate and obtain seedlings that allow to start this practice. Objective. The present research evaluates the percentage of germination of two varieties of lettuce (Lactuca sativa), Milanesa and Conconina, to determine if there is a significant difference in their germination to obtain seedlings. Materials and methods. A factorial design 2 2 was developed, taking into consideration the combinations of variety and luminosity; a statistical model was proposed to describe its behavior. Results. The most influential factor in the percentage of germination is the variety, the best results were found Milanesa variety under natural Light conditions. Conclusions. The Milanesa variety is a good option to generate seedlings and, under natural Light conditions, a germination percentage of 92.5% can be obtained, a value higher than that reported by the producer.
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