Abstract (Introduction): Within the framework of the present capitalist system, human beings have become an important polluting agent. Current production and consumption processes do not consider the existence of finite natural resources and a planet incapable of treating the waste that the prevailing way of life generates. Given these circumstances, the study of non-linear models is of interest, which make a more rational use of the waste that the productive activity generates, favoring recycling mechanisms. The phenomenon of recycling becomes particularly relevant in the case of electrical and electronic devices, whose ability to be degraded and metabolized by planet Earth is extremely difficult. (Objective): Evaluate the feasibility of installing and starting a recycling plant for electrical and electronics items in the town of Bahía Blanca (Argentina), during 2021. (Methodology): The conventional method for evaluating investment projects was used, considering technical, legal and economic aspects. (Results): The project is not acceptable according to the profitability intended by the investor. The possibility of financing was also included, which made the project even less profitable, and the sensitivity of the results was measured, finding that the price should be 1.48 % higher than that used in the analysis. (Conclusions): Other alternatives must be explored to make this proposal profitable from an economic and financial point of view.

Resumen (Introducción): En el marco del sistema capitalista vigente, el ser humano se ha transformado en un agente significativo de contaminación. Las dinámicas productivas y de consumo actuales no contemplan la existencia de recursos naturales finitos y de un planeta incapaz de procesar los desperdicios que el modo de vida habitual genera. Dadas estas circunstancias, cobra interés el estudio de modelos no lineales, que hagan un uso más racional de los residuos derivados de la actividad productiva, los cuales favorezcan mecanismos de reciclaje. El fenómeno del reciclaje se vuelve, en particular, relevante para el caso de los artefactos eléctricos y electrónicos; la capacidad del planeta Tierra para degradarlos y metabolizarlos resulta sumamente difícil. (Objetivo): Evaluar la factibilidad de la instalación y puesta en marcha de una planta recicladora de artículos eléctricos y electrónicos en la localidad de Bahía Blanca (Argentina), durante el 2021. (Metodología): Se utilizó la metodología convencional de evaluación de proyectos de inversión, considerando aspectos técnicos, legales y económicos. (Resultados): El proyecto no es aceptable según la rentabilidad pretendida por el inversor. También se incluyó la posibilidad de un financiamiento, lo que hizo que el plan fuera menos rentable aún, y se midió la sensibilidad de los resultados: se halló que el precio debiera ser 1.48 % superior al utilizado en el análisis. (Conclusiones): Se deben explorar otras alternativas para lograr que el proyecto sea rentable desde el punto de vista económico-financiero.

RESUMO: O uso de métodos não destrutivos e de baixo custo para determinação de área foliar tem ganhado importantes aplicações. Os objetivos da pesquisa foram (i) propor um método não destrutivo para estimar a área foliar da cultura da mamona e (ii) construir equações que estimem com precisão e rapidez a área foliar da espécie. Foram coletadas mil folhas sadias e expandidas de cinco cultivares de mamona (New Zealand Purple, Sipeal, Carmencita, Amarelo de Irecê e IAC-80), sendo coletadas 200 folhas de cada uma. O comprimento máximo, largura máxima e área foliar foram calculados para cada folha. Foi calculado o produto entre comprimento e largura (LW). Foram realizados testes com diferentes modelos de regressão linear e não linear entre área foliar e dimensões lineares das folhas de cada cultivar. Os modelos utilizados foram linear, linear sem intercepto e potência. Os critérios para escolha dos melhores modelos para estimar a área foliar da mamona foram maior coeficiente de determinação, maior coeficiente de correlação linear de Pearson, menor critério de informação de Akaike, maior índice de concordância de Willmott e menor raiz do erro quadrático médio. As equações que apresentaram melhores critérios para estimativa da área foliar das cultivares de mamona foram aquelas que utilizaram o produto entre comprimento e largura, em comparação às equações que utilizaram apenas uma dimensão foliar. O modelo ŷ = 0,439 × LW pode ser utilizado para estimar com precisão e rapidez a área foliar da mamona por meio de medidas lineares das folhas, utilizando o produto entre comprimento e largura (LW), independente da cultivar escolhida. RESUMO aplicações i (i ii (ii espécie New Purple Sipeal Carmencita IAC80, IAC80 IAC 80 , IAC-80) 20 máximo folha LW. . (LW) potência Pearson Akaike médio 0439 0 439 0,43 LW, escolhida IAC8 8 IAC-80 2 (LW 043 43 0,4 IAC-8 04 4 0, IAC-

ABSTRACT: Using non-destructive and low-cost methods to determine leaf area has gained important applications. The research objectives were (i) to propose a non-destructive method to estimate the leaf area of castor bean crops and (ii) to build equations that accurately and quickly estimate the leaf area of specie. One thousand healthy and expanded leaves of five castor bean cultivars (New Zealand Purple, Sipeal, Carmencita, Amarelo de Irecê, and IAC-80) were collected, and 200 leaves were collected from each. The maximum length, maximum width, and leaf area were calculated for each leaf. The product between length and width (LW) were calculated. We performed tests with different linear and non-linear regression models between leaf area and linear leaf dimensions of each cultivar. The models used were linear, linear without intercept, and power. The criteria for choosing the best models to estimate the leaf area of castor beans were a higher coefficient of determination, more elevated Pearson’s linear correlation coefficient, lower Akaike information criterion, higher Willmott agreement index, and smallest root mean square error. The equations that presented the best criteria for estimating the leaf area of castor bean cultivars were those that used the product between length and width, compared to equations that used only one leaf dimension. The model ŷ = 0.439 × LW can be used to accurately and quickly estimate the castor bean leaf area through linear measurements of the leaves, using the product between length and width (LW), regardless of the cultivar chosen. ABSTRACT nondestructive non destructive lowcost low cost applications i (i ii (ii specie New Purple Sipeal Carmencita Irecê IAC80 IAC 80 IAC-80 20 (LW nonlinear intercept power determination Pearsons Pearson s criterion index error dimension 0439 0 439 0.43 LW, , chosen IAC8 8 IAC-8 2 043 43 0.4 IAC- 04 4 0.

Abstract Introduction: Anxiety, depression and stress are becoming more and more frequent, especially since the COVID-19 health crisis. The main objective of this study was to analyse the predictive power of age, gender, emotional intelligence, and resilience with respect to anxiety, depression, and stress-related symptoms in a Spanish population sample. Method: A total of 427 Spanish participants, between 18 and 83 years of age, were assessed through self-report instruments (TMMS-24; BRCS; BASS-21). Hierarchical regression models (HRM) and non-linear methodologies (qualitative comparative analysis or QCA models) are used. Results: The HRM showed that emotional attention, clarity, and repair significantly predicted anxiety, depression, and stress. Gender also played a significant role, with women showing higher levels of anxiety and stress. Age and resilience were not significant predictors in the HRM. However, the QCA models revealed more nuanced interactions: high depression was linked to young age, high emotional attention, and low emotional clarity and repair. High anxiety was predicted by being female, young, with low emotional regulation, and high emotional attention. High stress was associated with being female, low resilience, and high emotional attention. Conversely, low levels of depression, anxiety, and stress were consistently associated with high resilience and emotional clarity and regulation. Conclusions: We consider these results to be of great interest for gaining a deeper understanding of the interaction between the variables under study. In this way, it will be possible to design more effective interventions that benefit from the maximum knowledge regarding the role of these variables.

Resumen Introducción: La ansiedad, la depresión y el estrés son cada vez más frecuentes, especialmente desde la crisis sanitaria del COVID-19. El objetivo principal de este artículo es analizar el poder predictivo de la edad, el sexo, la inteligencia emocional y la resiliencia respecto a los síntomas ansiosos, depresivos y el estrés en una muestra de población española. Método: Un total de 427 participantes españoles, con edades entre 18 y 83 años, fueron evaluados mediante instrumentos de autoinforme (TMMS-24; BRCS; BASS-21). Se utilizan modelos de regresión jerárquica (RLJ) y metodologías no lineales (modelos de análisis comparativo cualitativo o QCA). Resultados: Los RLJ mostraron que la atención emocional, la claridad y la reparación predecían significativamente la ansiedad, la depresión y el estrés. El género también desempeñó un papel significativo, ya que las mujeres mostraron mayores niveles de ansiedad y estrés. La edad y la resiliencia no fueron predictores significativos en la HRM. Sin embargo, los modelos QCA revelaron otras interacciones: la depresión estaba relacionada con una menor edad, la atención emocional alta y la claridad y la reparación emocional bajas. La ansiedad elevada se predijo por ser mujer, joven, con baja regulación emocional y alta atención emocional. El estrés elevado se asoció con ser mujer, tener baja resiliencia y una atención emocional elevada. Por el contrario, los niveles bajos de depresión, ansiedad y estrés se asociaron de forma consistente con una alta resiliencia y claridad y regulación emocional. Conclusiones: Consideramos que estos resultados son de gran interés para profundizar en el conocimiento de la interacción entre las variables objeto de estudio. De este modo, será posible diseñar intervenciones más eficaces que se beneficien del máximo conocimiento sobre el papel de estas variables.

ABSTRACT The drying process is paramount for maintaining seed quality, where the temperature during this process directly influences germination and vigor, especially for vegetable species harvested with high moisture content. This research aimed to determine and model the drying curves of S. aethiopicum (cultivar Tinguá-verde-claro) seeds at temperatures of 35, 38, 41, and 44 ºC, as well as to evaluate the physiological quality of the seeds after drying. A completely randomized design was used, with four drying temperatures (35, 38, 41, and 44 ºC) and four replicates. Nine mathematical models were fitted using the non-linear regression analysis by the Gauss-Newton method, and the goodness of fit was assessed based on the magnitude of the coefficient of determination (R2), chi-square test (χ2), relative mean error (P), and estimated mean error (SE). Seed quality was evaluated by germination test (G), electrical conductivity (EC), and accelerated aging (AA). The Modified Midilli model best represents the drying curves of S. aethiopicum seeds at the studied temperatures. Seeds with higher germination and vigor, meaning lower electrical conductivity values and higher germination rates after accelerated aging, are achieved through drying at 35 and 38 ºC. vigor content S cultivar Tinguáverdeclaro Tinguá verde claro Tinguá-verde-claro 41 4 ºC used (35 replicates nonlinear non linear GaussNewton Gauss Newton method R2, R2 R , (R2) chisquare chi square χ2, χ2 χ (χ2) P, P (P) SE. SE . (SE) G, G (G) EC, EC (EC) AA. AA (AA) 3 (3 (R2 (χ2 (P (SE (G (EC (AA ( (R (χ

RESUMO O processo de secagem é de suma importância para a manutenção da qualidade das sementes, onde a temperatura de condução deste processo exerce influência direta sobre a germinação e vigor, sobretudo para as espécies olerícolas que são colhidas com alto teor de água. O objetivo desta pesquisa foi determinar e modelar as curvas de secagem de sementes de jiló (cultivar Tinguá-verde-claro) nas temperaturas de 35, 38, 41 e 44 ºC, bem como avaliar a qualidade fisiológica das sementes após a secagem. Foi utilizado o delineamento inteiramente casualizado, sendo quatro temperaturas de secagem (35, 38, 41 e 44 ºC) com quatro repetições. Nove modelos matemáticos foram ajustados por meio de análise de regressão não linear pelo método de Gauss-Newton, e o grau de ajuste foi avaliado com base na magnitude do coeficiente de determinação (R2), teste qui-quadrado (χ2), erro médio relativo (P) e erro médio estimado (SE). A qualidade das sementes foi avaliada pelo teste de germinação (G), condutividade elétrica (CE) e envelhecimento acelerado (EA). O modelo ‘Midilli Modificado’ é o que melhor representa as curvas de secagem das sementes de jiló nas temperaturas estudadas. Sementes com maior germinação e vigor, ou seja, com menores valores de CE e maiores taxas de germinação após EA, são alcançadas através da secagem a 35 e 38 ºC. vigor água cultivar Tinguáverdeclaro Tinguá verde claro Tinguá-verde-claro 4 ºC casualizado (35 repetições GaussNewton, GaussNewton Gauss Newton, Newton Gauss-Newton R2, R2 R , (R2) quiquadrado qui quadrado χ2, χ2 χ (χ2) P (P SE. SE . (SE) G, G (G) (CE EA. EA (EA) Midilli Modificado estudadas seja 3 (3 (R2 (χ2 (SE (G (EA ( (R (χ

Abstract Objective: review some theoretical fundamentals and at the same time carry out empirical tests that support Thirlwall's (1974) approach in which he considered the existence of an optimal inflation rate that can accelerate the process of economic growth. Method: Time series models of nonlinear estimation of heteroscedasticity and consistent autocorrelation of autoregressive error correction are used. Results: the countries in the sample have an optimal inflation threshold higher than their current inflation target. The main limitation is the lack of statistical data for a larger set of countries, especially developing ones, as well as the lack of statistical significance with the use of certain econometric modeling structures. The main contribution and originality of the work lies in the use of econometric models that simulate the equalization between the guaranteed growth rate with respect to the natural one, allowing us to identify that it is sensible to consider that the inflation of various economies cannot be found exclusively in reduced ranges.

Resumen La presente investigación tiene por objetivo revisar algunos fundamentales teóricos y realizar pruebas empíricas que respalden el enfoque de Thirlwall (1974) en el que consideró la existencia de una tasa de inflación óptima que puede acelerar el proceso de crecimiento económico versus los argumentos del modelo de metas de inflación. Nuestra metodología utiliza series de tiempo de estimación no lineal de heteroscedasticidad y autocorrelación consistente de corrección de error autorregresivo. De manera general, los países de la muestra presentan un umbral de inflación óptima superior a su inflación objetivo. Se encontraron algunas limitaciones debido a la falta de datos estadísticos para un conjunto más extenso de países, sobre todo en vías de desarrollo, así como la falta de significancia estadística con el uso de determinadas estructuras de modelado econométrico. La aportación principal y originalidad del trabajo reside en el uso de modelos econométricos que simulan la igualación entre la tasa de crecimiento garantizada con respecto a la natural, permitiendo identificar que es sensato considerar que la inflación de diversas economías no se puede encontrar exclusivamente en rangos reducidos.

Abstract A comparison is established between the traditional design of the linear economy and that of a circular economy through the proposal of heuristic dynamic models based on non-linear systems of ordinary differential equations. It was found that, for critical values of the control parameter, natural resources, through an Andronov-Hopf bifurcation, the circular economy model self-organizes out of thermodynamic equilibrium, and exhibits high complexity, robustness, resilience and adaptability, which was verified by evaluating the Shannon entropy of their trajectories. Finally, it was shown, through an ansatz, that the circular economy model shows greater efficiency compared to the traditional linear model.

Resumen Se establece una comparación entre el diseño tradicional de la economía lineal y el de una economía circular a través de la propuesta de modelos dinámicos heurísticos basados en sistemas no lineales de ecuaciones diferenciales ordinarias. Se encontró que, para valores críticos del parámetro de control, los recursos naturales, a través de una bifurcación de Andronov-Hopf, el modelo de economía circular se autorganiza fuera del equilibrio termodinámico, y exhibe una alta complejidad, robustez, resiliencia y adaptabilidad, lo cual se verificó a través de evaluar la entropía de Shannon de sus trayectorias. Finalmente, se mostró por medio de un ansatz, que el modelo de economía circular muestra una mayor eficiencia en comparación con el modelo tradicional lineal.

Resumen: El método de análisis estático no lineal ha facilitado modelos más cercanos a la respuesta estructural para fuertes movimientos sísmicos. Por lo tanto, se desarrolló una evaluación del desempeño sísmico de un edificio de sala multiusos ubicado en una universidad nacional pública de Chiclayo-Perú, aplicando el análisis estático no lineal, la cual contiene dos módulos semejantes de 3 niveles c/u con plantas irregulares. El sistema estructural de la edificación es de muros portantes. Fue construida en el año 2010 y fue diseñada de acuerdo a la E.030 (Norma sismo resistente peruana) y con la microzonificación sísmica de Perú. Para efectos prácticos, tomando en consideración la simetría de la estructura global, se evaluó uno de los módulos utilizando métodos no lineales que puedan simular el efecto de sismos. Este desarrollo incluía la aplicación de un análisis lineal para establecer los espectros de respuesta y a partir de ello ejecutar el análisis no lineal Pushover. En base a los resultados, se determinó el desempeño en las dos direcciones, tomando en cuenta los niveles de desempeño de la HAZUS y VISION 2000. Los resultados muestran que la edificación tiene un desempeño de "Seguridad de vida " y "Cerca al colapso " en la dirección X y Y respectivamente; además de ello, las derivas muestran una estrecha relación con los datos de desempeño, pues HAZUS demuestra que las derivas en Y no son favorables; por lo tanto, se determinó que es necesario que se ejecute un reforzamiento estructural de la edificación para mejorar el comportamiento desfavorable.

Abstract: The nonlinear static analysis method has facilitated models that are closer to the structural response for strong seismic movements. Therefore, a seismic performance evaluation of a multi-purpose hall building located in a national public university in Chiclayo, Peru, was developed, applying the nonlinear static analysis. This building comprises two similar modules, each with 3 levels and irregular plans. The building's structural system consists of load-bearing walls. It was constructed in 2010 and designed according to E.030 (the Peruvian seismic-resistant standard) and Peru's seismic microzonation. For practical purposes, considering the symmetry of the overall structure, one of the modules was evaluated using nonlinear methods capable of simulating the effect of earthquakes. This development included applying a linear analysis to establish the response spectra and, based on that, performing the nonlinear Pushover analysis. Based on the results, the performance in both directions was determined, considering the performance levels of HAZUS and VISION 2000. The results show that the building has a performance of "Life Safety" and "Near Collapse" in the X and Y directions, respectively. Additionally, the drifts show a close relationship with the performance data, as HAZUS demonstrates that the drifts in the Y direction are not favorable. Therefore, it was determined that structural reinforcement of the building is necessary to improve its unfavorable behavior.

Abstract: The objective of this research study is to develop a simple application on Microsoft Excel for univariate statistical analysis of experiments. Classic ANOVA procedures are included for models with or without factorial structure (double or triple, including additional treatments), split-plot, split-block, simple nested, and repeated ANOVA measures of balanced or unbalanced data. The tool can run average tests and perform regression analysis for linear and non-linear models. The application automatically performs tests for normality, homoscedasticity, and additivity requirements. In case of violation, the program also automatically scans for outliers or a suitable data transformation. The application also allows the performance of ANCOVA and provides the Papadakis method for correction of spatial autocorrelation and other analyses. The application (available for free at speedstatsoftware.wordpress.com in English, Portuguese, and Spanish) has been tested with the resolution of hundreds of examples and is also adapted for use in LibreOffice.

Resumen: El objetivo de esta investigación es desarrollar una aplicación sencilla en Excel para el análisis estadístico univariado de experimentos. Se incluyen procedimientos de ANOVA clásicos con o sin estructura factorial (doble o triple, incluyendo tratamientos adicionales), de parcela dividida, de split-blocks, nested y ANOVA de medidas repetidas para datos balanceados o desbalanceados. La herramienta puede ejecutar pruebas de promedios y análisis de regresión para modelos lineales y no lineales. La aplicación realiza automáticamente pruebas para verificar los requisitos de normalidad, homocedasticidad y aditividad. En caso de infracción, el programa también busca automáticamente valores atípicos o recomienda una transformación de datos adecuada. El software también permite la realización de ANCOVA y proporciona el método Papadakis para la corrección de autocorrelación espacial, entre otros análisis. La aplicación (disponible de forma gratuita en speedstatsoftware.wordpress.com, con versiones en inglés, portugués y español) ha sido probada con éxito en la resolución de cientos de ejemplos y también ha sido adaptada para su uso en LibreOffice.

Abstract: This research proposes two models for the problem of short-term economic dispatch of electrical power systems through nonlinear programming (NLP). The problems raised will be resolved through the cost function of the classic economic dispatch where thermal and hydraulic generation plants will be considered to obtain the electrical power generated in each of the nodes. The proposed methodology will be used for a short-term period of 24 hours with different hourly demand, as it is a short-term dispatch, it focuses on the delivery of power that covers the designated demand in each schedule, so it will not consider a deficit cost or uncertainty in the variables in any of the cases. In the first instance, the model will be developed for a single node with cascade reservoirs, while the second case will be developed in the IEEE 14-bus system. The non-linear programming shows satisfactory results, complying with the operational restrictions implemented in the mathematical model, in addition, the participation of thermal generation is considerably reduced, which represents a lower cost. The first model of a node is validated through bibliography, obtaining an operating cost of $904,990. In the same way, complying with all the designated parameters, the second model obtains a total cost of $129,800, satisfying the total demand in both cases, subject to each of its restrictions.

Resumen: La presente investigación propone dos modelos al problema de despacho económico a corto plazo de los sistemas eléctricos de potencia por medio de la programación no lineal (PNL). Los problemas planteados serán resueltos mediante la función de costo del despacho económico clásico en donde se considerarán centrales de generación térmica e hidráulicas para obtención de la potencia eléctrica generada en cada uno de los nodos, la metodología propuesta será utilizada para un periodo a corto plazo de 24 horas con diferente demanda horaria, al ser un despacho a corto plazo este se enfoca en la entrega de potencia que cubra la demanda designada en cada horario, por lo que no considerará para ninguno de los casos un costo de déficit o incertidumbre en las variables. En primera instancia se desarrollará el modelo para un solo nodo con embalses en cascada, mientras que el segundo caso será desarrollado en el sistema de 14 buses de la IEEE. La programación no lineal muestra resultados satisfactorios cumpliendo con las restricciones operativas implementadas en el modelo matemático, además se reduce considerablemente la participación de generación térmica lo que representa menor costo, el primer modelo de un nodo es validado mediante bibliografía obteniendo un costo de operación de $904.990. De la misma forma, cumpliendo con todos los parámetros designados, el segundo modelo llega a obtener un costo total de $129.802,16 satisfaciendo el total de la demanda en ambos casos, sujeto a cada una de sus restricciones.

Abstract: Recent applications demonstrated how fiber-reinforced polymer (FRP) composites can improve the structural capabilities of glulam beams, particularly regarding their flexural and shear strength. With the development of precise numerical models, such systems can be optimized. There is currently a dearth of information in the literature on numerical models that can accurately anticipate the nonlinear behavior of low-grade glued laminated timber beams reinforced with FRP. In this study, larch beams were reinforced with carbon fiber reinforced polymer fabric 1, 2 and 3 layers. The effect of the number of floors on the flexural properties of the beams in reinforcement was investigated experimentally and numerically. As a result of the study, the best flexural properties were achieved with 3-layer reinforcement. It was observed that 1- and 2-layer reinforcement compared to the reference beam were also significantly effective. Numerical analyzes gave close values with experimental test results. As a result of comparing the results obtained from the numerical model with the experimental findings, it was concluded that the FRP fabric managed to significantly increase the performance of larch timber. The model is a useful tool for examining the effect of reinforcement coefficient and will be used for optimization of the larch beam

Abstract: Steel fiber reinforced concrete, compared to the conventional concrete; is a composite building material that performs much better in terms of parameters such as ductility, energy absorption capacity, fracture toughness, fatigue resistance, and the use of steel fiber reinforced concrete (SFRC) in structures has become widespread. In this study, a nonlinear finite element model (FEM) has been developed that can represent the behavior of beams produced by using steel fiber concrete subjected to impact load. For this purpose, a finite element model of beam series produced with fiber-reinforced concrete obtained from the literature was created. The ABAQUS package program was used to create models simulating the behavior. Numerical results showed that the model could successfully capture the experimental results of beams selected from the literature. In addition to simulation, a parametric study was also performed to investigate the effect of stirrups, reinforcement ratio, and drop height on the behavior of SFRC beams under impact loads. The results of the parametric study showed that increasing the fiber ratio and reinforcement ratio positively affected the behavior of SFRC beams in terms of displacement recovery

Abstract The aim of this study was to examine the impact of both organic and inorganic nitrogen fertilizers on the intensity and epidemiological components of Cercospora leaf spot across three different canopies of cotton plants, specifically the variety DP ACALA 90, under field conditions. Fertilizers used in the study included bovine manure, Jatropha curcas seedcake, poultry manure, and urea (the latter serving as a control). These were applied at 20 days after plant emergence and then during the flowering stage until the total nitrogen (N) dose reached 50, 100, 150, or 200 kg N per hectare. The incidence and severity of the disease were assessed starting at the reproductive stage B1 (the first visible flower bud) across the lower, middle, and upper canopies of four cotton plants, with six evaluations conducted over time. To calculate the initial inoculum (Y 0 ) and the disease progress rate (r), the Exponential, Gompertz, and Logistic models were employed based on temporal data. The study was designed as a randomized complete block with a 4x4 factorial arrangement (fertilizer type x dose), and mean comparisons were made using Tukey's test (p ≤ 0.05). It was found that disease intensity within each canopy level varied in response to the type of nitrogen source and the applied dose, with the severity of the disease (including the area under the disease progress curve) being particularly influenced. A significant interaction between the type of fertilizer and the dose regarding the intensity of Cercospora leaf spot was observed. The Exponential model most accurately depicted the disease's temporal progression. Notably, poultry manure and urea were the fertilizers that most adversely influenced the intensity and initial inoculum (Y 0 ) of Cercospora leaf spot across the various canopies of the cotton plants. The findings suggest that the use of organic fertilizers in cotton cultivation could represent a viable sustainable management strategy.

Resumen: En el presente estudio, se analiza el desempeño sísmico de un sistema dual de hormigón armado (pórticos y muros especiales) con diferentes niveles de irregularidad torsional. Se plantean tres arquetipos, cada uno con un nivel de irregularidad torsional distinto (IT 1.0, IT 1.2 e IT 1.4) con la finalidad de evaluar el efecto de la irregularidad torsional en el desempeño sísmico. Los elementos estructurales de los arquetipos cumplen con el diseño sismorresistente. Además, se tomó en cuenta los factores de sobre-resistencia y amplificación dinámica para determinar el corte de diseño en los muros estructurales. Se realizaron análisis estático y dinámicos no lineales para cuantificar las respuestas globales y locales de cada uno de los modelos. Los modelos analíticos de muros estructurales son calibrados en función de los datos obtenidos en ensayos experimentales existentes, de esta manera se valida los elementos tipo fibra (infrmFB) usados y los parámetros de los modelos constitutivos de los materiales. Se realizan análisis dinámicos incrementales (IDA) para cada uno de los arquetipos con los once registros sísmicos seleccionados de la base del PEER. Las curvas IDA son desarrolladas con dos parámetros de demanda ingenieril: derivas de piso y deformaciones unitarias. Finalmente, se elaboran las curvas de fragilidad para los niveles de desempeño de ocupación inmediata, seguridad de vida y prevención de colapso, y se determinan los coeficientes de margen con la finalidad de cuantificar las probabilidades de alcanzar los niveles de desempeño mencionados.

Abstract: This research evaluates the seismic performance of a dual reinforced concrete system with different levels of torsional irregularity. Three archetypes are proposed, each of them with a different level of torsional irregularity (IT 1.0, IT 1.2 and IT 1.4) in order to evaluate the effect of torsional irregularity on seismic performance. The structural elements of the archetypes comply with the seismic design. In addition, the factors of overstrength and dynamic amplification were considered to determine the design shear force in the structural walls. Linear static and nonlinear dynamic analysis were performed to quantify the global and local responses of each of the models. The analytical models of structural walls are calibrated based on the data of existing experimental tests, thus validating the fiber-type elements (infrmFB) used and the parameters of the constitutive models of the materials. Incremental dynamic analysis (IDA) is performed for each of the archetypes with the eleven seismic records selected from the PEER database. IDA curves are developed with two engineering demand parameters: story drifts and strains. Finally, the fragility curves are elaborated for the immediate occupancy, life safety, and collapse prevention performance levels, and the margin ratio are determined to quantify the probabilities of reaching a certain level of performance.

Resumen En América Latina se ha popularizado el uso de muros de concreto reforzado como sistema estructural para la construcción de edificaciones; sin embargo, este sistema se caracteriza por ser de baja ductilidad por lo cual su desempeño se ha visto comprometido durante diferentes sismos ocurridos en los últi-mos años. Esta investigación toma tres edificios reales con estructuras de muros en concreto reforzado, localizados en zonas de sismicidad alta y en un suelo tipo D, los cuales se diseñan según la normativa colombiana. Adicionalmente, se crean modelos numéricos no lineales para evaluar el comportamiento sísmico de los edificios ante sismos reales. Este mismo procedimiento es repetido para los tres edificios dotándolos con aisladores sísmicos y comparando su desempeño sísmico con el obtenido de los aná-lisis de los edificios de base fija. Los resultados muestran que se mejora el desempeño de la estructura aislada ante la ocurrencia de los sismos pasando de un nivel de desempeño de protección de la vida a uno de ocupación inmediata, mientras se obtiene una reducción de hasta un 50% del acero de refuerzo y de hasta un 100% del uso de elementos de borde comparado con los edificios diseñados con base fija, conservando las ventajas constructivas y arquitectónicas del sistema de muros.1 Universidad Nacional de Colombia, Manizales, Colombia2University School for Advanced Studies IUSS Pavia, Italia.

Abstract The use of reinforced concrete walls has become popular in Latin America as a structural system for the construction of residential buildings. However, this system is characterized by a low ductility capacity, compromising its seismic performance during the last strong earthquakes. To improve the seismic performance of reinforced concrete walls, building codes have increased the design requirements such as augmenting the use of boundary elements, larger cross sections and safety factors. These new requirements lead to higher building costs without assuring obtaining higher levels of seismic performance, becoming necessary the implementation of novel technologies that allow the improvement of the seismic performance of this structural system. Seismic isolation allows for reducing the seismic demand on the structure and increasing the seismic performance without incurring larger design values. This study uses three real buildings composed of reinforced concrete walls located in a high seismic region and soil type D, designed based on the Colombian building code. Nonlinear models of these three buildings were generated to evaluate the seismic response under actual ground motions. The three buildings were then redesigned using seismic isolation and the same analysis procedure was carried out to obtain the seismic response of the isolated buildings, comparing the results with those of the fixed base. The results show that the seismically isolated buildings exhibited a higher seismic performance, moving from a life safety performance level of the fixed-base buildings to an immediate occupancy performance level. In addition, the isolated buildings required up to 50% less reinforced steel and up to 100% fewer boundary elements compared to the fixed-base buildings, while keeping the architectural and building advantages of the wall structural system.

Resumen Este artículo presenta un modelamiento para la caracterización de dos bombas peristálticas utilizando regresión no lineal. Se realizaron pruebas de precisión variando el nivel de altura de la bomba respecto al recipiente y se concluye que esto no influye en la rapidez del flujo. Se tomaron datos de llenado para 300ml teniendo en cuenta el voltaje aplicado a las bombas y el tiempo de llenado. Con los datos registrados se realizó ajuste de curvas por mínimos cuadrados determinando el modelo exponencial como el más acertado para las dos bombas y aplicando regla de tres simple se halló la ecuación para cualquier volumen solicitado. Finalmente se realizaron pruebas de llenado para comparar los datos del modelo con datos reales. El coeficiente de determinación del modelo de la primera bomba fue de 0,9875 y para la segunda fue de 0,9956 concluyendo que los modelos son acertados, lo cual se reitera en las pruebas de llenado comparativas donde se evidencia un asertividad superior a 99% en todas las pruebas realizadas. Se sugiere ampliar las investigaciones en el uso de este método matemático como alternativa en el control no invasivo de fluidos cuyos instrumentos requieran un tratamiento estéril.

Abstract This paper presents a modeling approach to characterize two peristaltic pumps using nonlinear regression. Accuracy tests were performed by varying the height level of the pump with respect to the vessel, and it was found to have no effect on the flow rate. Filling data was recorded for 300 ml considering the voltage applied to the pumps and the filling time. A least squares curve fitting was performed with the recorded data. The exponential model was determined to be the most accurate for the two pumps, and using a simple rule of three, the equation for each desired volume was found. Finally, filling tests were performed to compare the model data with the real data. The coefficient of determination of the model for the first pump was 0.9875 and for the second pump was 0.9956. It can be concluded that the models are accurate, which is also confirmed in the comparative filling tests, where an assertiveness of more than 99% was demonstrated in all the tests performed. It is proposed to extend the studies on the use of this mathematical method as an alternative in the non-invasive control of fluids whose instruments must be handled in a sterile manner.