33 research outputs found
MCR-ALS on metabolic networks: Obtaining more meaningful pathways
[EN] With the aim of understanding the flux distributions across a metabolic network, i.e. within living cells, Principal Component Analysis (PCA) has been proposed to obtain a set of orthogonal components (pathways) capturing most of the variance in the flux data. The problems with this method are (i) that no additional information can be included in the model, and (ii) that orthogonality imposes a hard constraint, not always reasonably. To overcome these drawbacks, here we propose to use a more flexible approach such as Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) to obtain this set of biological pathways through the network. By using this method, different constraints can be included in the model, and the same source of variability can be present in different pathways, which is reasonable from a biological standpoint. This work follows a methodology developed for Pichia pastoris cultures grown on different carbon sources, lately presented in GonzĂĄlez-MartĂnez et al. (2014). In this paper a different grey modelling approach, which aims to incorporate a priori knowledge through constraints on the modelling algorithms, is applied to the same case of study. The results of both models are compared to show their strengths and weaknesses.Research in this study was partially supported by the Spanish Ministry of Science and Innovation and FEDER funds from the European Union through grants DPI2011-28112-C04-01 and DPI2011-28112-C04-02. The authors are also grateful to Biopolis SL for supporting this research.Folch-Fortuny, A.; Tortajada Serra, M.; Prats-MontalbĂĄn, JM.; Llaneras Estrada, F.; PicĂł Marco, JA.; Ferrer Riquelme, AJ. (2015). MCR-ALS on metabolic networks: Obtaining more meaningful pathways. Chemometrics and Intelligent Laboratory Systems. 142:293-303. https://doi.org/10.1016/j.chemolab.2014.10.004S29330314
Distribuição de potåssio em gotejamento com fertirrigação em diferentes pontos de injeção na linha principal
[EN] The purpose of this research was to evaluate the K2O distribution uniformity by surface drip irrigation at Universitat Politecnica de Valencia, Valencia, Spain (39Âș 29âČ N, 0Âș 23âČ W, 20 m). The irrigation was performed by drip lines with not-compensated emitters, spaced 0.3 m. The fertigation was realized using a fertilizer injector pump of electric action with injection of 0.25 h. The experimental design used completely randomized blocks with five treatments and four replications. The treatments consisted of injection in five distances, located at 10; 20; 30; 40; 50 m of the first drip line. Samples were collected in emitters located at the start, at 1/3, at 2/3 and at the end of the drip lines. The nutrient concentration was determined by flame spectrophotometry. The Christiansen's uniformity coefficients (CUC), of distribution (DUC), of statistical (SUC) and of emission (eUC) were estimated. The K2O concentration and distribution decreased linearly with the increase of the injection distance. In all treatments, the CUC, SUC and DUC were described as 'excellent'. The eUC was described as 'recommended' only at smaller injection distances.[PT] Objetivando fornecer subsĂdios para os produtores aperfeiçoarem o manejo da
fertirrigação em pequenas ĂĄreas, avaliou-se, na Universitat PolitĂšcnica de ValĂšncia, ValĂȘncia,
Espanha (39° 29âČ N, 0° 23âČ W, 20 m), a uniformidade de distribuição do K2O via irrigação por
gotejamento superficial em função da distùncia do ponto de injeção na linha principal. A irrigação
foi efetuada por linhas laterais com emissores não compensantes, espaçados de 0,3 m. Na
fertirrigação, foi utilizada uma bomba injetora de fertilizante de acionamento elétrico, com o tempo
de injeção de 0,25 h. O delineamento experimental foi o de blocos casualizados, com cinco
tratamentos e quatro repetiçÔes. Os tratamentos consistiram em cinco pontos de injeção na linha
principal, situados a: 10; 20; 30; 40 e 50 m da primeira linha lateral. Foram coletadas amostras em
emissores localizados no inĂcio, a 1/3, a 2/3 e no final das linhas laterais. A concentração do
nutriente foi determinada por espectrofotometria de chama. Foram estimados os coeficientes de
uniformidade de Christiansen (CUC), de distribuição (CUD), estatĂstico (CUE) e de emissĂŁo (CUe).
A concentração e a distribuição de K2O diminuĂram linearmente com o aumento da distĂąncia do
ponto de injeção. Em todos os tratamentos, o CUC, CUE e CUD foram classificados como
âexcelenteâ. O CUe foi classificado como ârecomendadoâ apenas na menor distĂąncia de injeção.To the Coordination of Improvement of Higher Education Personnel (CAPES) for grant the Doctoral Sandwich Abroad scholarship and the Universitat PolitĂšcnica de ValĂšncia (UPV), for providing the experimental area and all equipment and supplies needed for the research.Do Bomfim, GV.; Manzano Juarez, J.; De Azevedo, BM.; Vasconcelos, DV.; Viana, TVDA. (2014). Potassium distribution in drip irrigation with fertigation for different injection distances in the main line. Engenharia AgrĂcola. 34(6):1151-1161. doi:10.1590/S0100-69162014000600011S1151116134
GeometrĂa y pĂ©rdidas de carga en inyectores Venturi mediante la dinĂĄmica de fluidos computacional
[EN] To determine the influence of geometry on the hydrodynamic behavior of Venturi injectors, using computational fluid dynamics techniques, we studied, at the Universitat PolitĂšcnica de ValĂšncia, Valencia, Spain, the geometric parameters that exert the most influence on head losses: the relationship between throat diameter and nozzle (ÎČ), nozzle angle (α1) and diffuser angle (α2). In addition, three throat morphologies (B1: nozzle-throat and throat-diffuser with a sharp edge; B2: nozzle-diffuser with a zero-length, sharp-edge throat; B3: nozzle-throat and throat-diffuser with rounded edge). We analyzed their influence on the velocity distribution and differential pressure between inlet and throat (DP/Îł), throat and outlet (Îhv/Îł), and outlet and throat ((P3-P2)/Îł). The development of the velocity profile from the throat is slower the greater ÎČ is and the lower α2 is. DP/Îł decreases with ÎČ, increases with α1 and varies little with α2. Îhv/Îł decreases with ÎČ and increases with α1 and α2. (P3-P2)/Îł decreases with ÎČ and increases with α1 and α2. Geometry B3 decreases the losses and delays the onset of cavitation. Thus, the lower ÎČ and the higher α2, the greater the losses; however, the influence of α1 is less clear. The rounded edges produce lower head losses.[ES] Estudio de la influencia de la geometrĂa en el comportamiento hidrodinĂĄmico de
inyectores Venturi mediante técnicas de dinåmica de fluidos computacional.
Para determinar la influencia de la geometrĂa en el comportamiento hidrodinĂĄmico de inyectores Venturi, mediante tĂ©cnicas de dinĂĄmica de fluidos computacional, se estudiĂł, en la Universitat PolitĂšcnica de ValĂšncia, Valencia, España, los parĂĄmetros geomĂ©tricos que mĂĄs influencian las pĂ©rdidas de carga: relaciĂłn entre diĂĄmetro de la garganta y tobera (ÎČ), ĂĄngulo de la tobera (α1) y ĂĄngulo del difusor (α2). AdemĂĄs, tres morfologĂas de la garganta (B1: tobera-garganta y garganta-difusor en arista viva; B2: tobera-difusor con garganta de longitud nula y en arista viva; B3: tobera-garganta y garganta-difusor en arista redondeadas). Se ha analizado su influencia en la distribuciĂłn de velocidad y en la presiĂłn diferencial entre entrada y garganta (DP/Îł), garganta y salida (âhv/Îł), y salida y garganta ((P3-P2)/Îł). El desarrollo del perfil de velocidades a partir de la garganta es mĂĄs lento cuanto mayor es ÎČ y menor es α2. DP/Îł disminuye con ÎČ, aumenta con α1 y es poco variable con α2. âhv/Îł disminuye con ÎČ y aumenta con α1 y α2. (P3-P2)/Îł disminuye con ÎČ y α1, yaumenta con y α2. La geometrĂa B3 disminuye las pĂ©rdidas y retarda la apariciĂłn de la cavitaciĂłn. AsĂ, cuanto menor es ÎČ y cuanto mayor es α2, mayores son las pĂ©rdidas de carga, sin embargo, la influencia de α1 no es tan clara. Las aristas redondeadas producen menores perdidas de cargaThe authors would like to thank the âConselleria d'Empresa, Universitat i CiĂšnciaâ of Generalitat Valenciana â Spain.Manzano Juarez, J.; Palau, CV.; De Azevedo, BM.; Do Bomfim, GV.; Vasconcelos, DV. (2016). Geometry and head loss in Venturi injectors through Computational Fluid Dynamics. Engenharia AgrĂcola. 36(3):482-491. doi:10.1590/1809-4430-Eng.Agric.v36n3p482-491/2016S482491363Baylar, A., Aydin, M., Unsal, M., & Ozkan, F. (2009). Numerical Modeling of Venturi Flows for Determining Air Injection Rates Using Fluent V6.2. Mathematical and Computational Applications, 14(2), 97-108. doi:10.3390/mca14020097Chan, L., Chin, C., Soria, J., & Ooi, A. (2014). Large eddy simulation and Reynolds-averaged Navier-Stokes calculations of supersonic impinging jets at varying nozzle-to-wall distances and impinging angles. International Journal of Heat and Fluid Flow, 47, 31-41. doi:10.1016/j.ijheatfluidflow.2014.02.005Dantas Neto, J., Maciel, J. L., Alves, A. de S., Azevedo, C. A. V. de, Fernandes, P. D., & Lima, V. L. A. de. (2013). Teores de macronutrientes em folhas de goiabeira fertirrigada com nitrogĂȘnio. Revista Brasileira de Engenharia AgrĂcola e Ambiental, 17(9), 962-968. doi:10.1590/s1415-43662013000900008Rezende, R., Helbel JĂșnior, C., Souza, R. S. de, Antunes, F. M., & Frizzone, J. A. (2010). Crescimento inicial de duas cultivares de cafeeiro em diferentes regimes hĂdricos e dosagens de fertirrigação. Engenharia AgrĂcola, 30(3), 447-458. doi:10.1590/s0100-69162010000300009Sanderse, B., Pijl, S. P., & Koren, B. (2011). Review of computational fluid dynamics for wind turbine wake aerodynamics. Wind Energy, 14(7), 799-819. doi:10.1002/we.458Santos, L. D. C., Zocoler, J. L., Justi, A. L., Silva, A. O., & Correia, J. D. S. (2012). ESTUDO COMPARATIVO DA TAXA DE INJEĂĂO EM INJETOR DO TIPO VENTURI COM E SEM VĂLVULA DE RETENĂĂO. IRRIGA, 1(01), 145. doi:10.15809/irriga.2012v1n01p145Sun, Y., & Niu, W. (2012). Simulating the Effects of Structural Parameters on the Hydraulic Performances of Venturi Tube. Modelling and Simulation in Engineering, 2012, 1-7. doi:10.1155/2012/458368Uribe, R. A. M., Gava, G. J. de C., Saad, J. C. C., & Kölln, O. T. (2013). Ratoon sugarcane yield integrated drip-irrigation and nitrogen fertilization. Engenharia AgrĂcola, 33(6), 1124-1133. doi:10.1590/s0100-69162013000600005Vasata, D., Galante, G., Rizzi, R. L., & Zara, R. A. (2011). Solução computacional do problema da cavidade cĂșbica atravĂ©s das equaçÔes de Navier-Stokes tridimensionais. Revista Brasileira de Ensino de FĂsica, 33(2), 1-10. doi:10.1590/s1806-11172011000200013Yeoh, G. H., Liu, C., Tu, J., & Timchenko, V. (2012). Computational Fluid Dynamics and Its Applications 2012. Modelling and Simulation in Engineering, 2012, 1-2. doi:10.1155/2012/61061
Design and prediction performance of Venturi injectors in drip irrigation
[EN] The design and prediction performance of four Venturi injector prototypes have been studied using Computational Fluid Dynamics (CFD) techniques. Results were compared with experimental tests carried out in the laboratory of the Universitat Politecnica de Valencia, Valencia, Spain. The analysed and selected geometries for each prototype were used to simulate the operation without nutrient injection (G1) and with nutrient injection (G2). In first case (G1), the results were presented in the form of pressure profile at the injector axe under different velocities and the pressure distribution in the whole geometry. Additionally, this paper analysed the evolution of pressures and head loss versus main water flow in the different prototypes. The relative error was estimated to compare CFD and experimental results. The second case (G2), the graphical representation for the relations between the nutrient aspiration flow and water main flow were obtained for numerical and experiment approaches. In conclusion, CFD techniques appear as a suitable tool for the analysis of the Venturi injector operation, but its validation with experimental data is recommended.[ES] En la Universitat PolitÚcnica de ValÚncia, Valencia, España, se ha estudiado el diseño y funcionamiento de cuatro
prototipos del inyector Venturi con técnicas de Dinåmica de Fluidos Computacional (CFD), comparåndo las
con ensayos en laboratorio. Para cada prototipo, las geometrĂas definidas y analizadas han permitido simular el
funcionamiento sin (G1) y con inyecciĂłn (G2) para quimigaciĂłn. En el caso G1, se presentan los grĂĄficos del perfil
de presiones en el eje del inyector para diversas velocidades, asĂ como la distribuciĂłn del campo de presiones
y de la evolución de las diferencias de presión y pérdidas de carga frente al caudal principal. Para comparar los
resultados obtenidos con CFD frente al resultado experimental, se calculĂł el error relativo. En el caso G2, se
obtuvo la representación gråfica del el caudal de inyección frente al caudal principal. Las técnicas CFD exigen un
buen ajuste del modelo para dar un resultado aceptable. Son interesantes para comparar geometrĂas, analizar sus
variantes, realizar prediseños y aproximar ordenes de magnitud, pero es recomendable su ensayo en laboratorio
para validar los resultados.Manzano Juarez, J.; De Azevedo, BM.; Do Bomfim, GV.; Royuela, A.; Palau Estevan, CV.; Viana, TVDA. (2014). Diseño y predicciĂłn del funcionamiento de inyectores Venturi en riego localizado. Revista Brasileira de Engenharia AgrĂcola e Ambiental - Agriambi. 18(12):1209-1217. doi:10.1590/1807-1929/agriambi.v18n12p1209-1217S120912171812Baylar, A., Aydin, M., Unsal, M., & Ozkan, F. (2009). Numerical Modeling of Venturi Flows for Determining Air Injection Rates Using Fluent V6.2. Mathematical and Computational Applications, 14(2), 97-108. doi:10.3390/mca14020097CIPOLLA, E., Silva, F., FILHO, G., & BARROS, R. (2011). Avaliação da Distribuição de Velocidades em Uma Bomba CentrĂfuga Radial Utilizando TĂ©cnicas de CFD. Revista Brasileira de Recursos HĂdricos, 16(3), 71-79. doi:10.21168/rbrh.v16n3.p71-79Davis, J. A., & Stewart, M. (2002). Predicting Globe Control Valve PerformanceâPart I: CFD Modeling. Journal of Fluids Engineering, 124(3), 772-777. doi:10.1115/1.1490108Coutier-Delgosha, O., Fortes-Patella, R., & Reboud, J. L. (2003). Evaluation of the Turbulence Model Influence on the Numerical Simulations of Unsteady Cavitation. Journal of Fluids Engineering, 125(1), 38-45. doi:10.1115/1.1524584Franklin, R. E., & Wallace, J. M. (1970). Absolute measurements of static-hole error using flush transducers. Journal of Fluid Mechanics, 42(1), 33-48. doi:10.1017/s0022112070001052Guo, B., Langrish, T. A. ., & Fletcher, D. F. (2002). CFD simulation of precession in sudden pipe expansion flows with low inlet swirl. Applied Mathematical Modelling, 26(1), 1-15. doi:10.1016/s0307-904x(01)00041-5Hatano, S., Kang, D., Kagawa, S., Nohmi, M., & Yokota, K. (2014). Study of Cavitation Instabilities in Double-Suction Centrifugal Pump. International Journal of Fluid Machinery and Systems, 7(3), 94-100. doi:10.5293/ijfms.2014.7.3.094Lindau, J. W., Kunz, R. F., Boger, D. A., Stinebring, D. R., & Gibeling, H. J. (2002). High Reynolds Number, Unsteady, Multiphase CFD Modeling of Cavitating Flows. Journal of Fluids Engineering, 124(3), 607-616. doi:10.1115/1.1487360Norton, T., Sun, D.-W., Grant, J., Fallon, R., & Dodd, V. (2007). Applications of computational fluid dynamics (CFD) in the modelling and design of ventilation systems in the agricultural industry: A review. Bioresource Technology, 98(12), 2386-2414. doi:10.1016/j.biortech.2006.11.025Palau-Salvador, G., Gonzalez Altozano, P., & Arviza-Valverde, J. (2007). Numerical modeling of cavitating flows for simple geometries using FLUENT V6.1. Spanish Journal of Agricultural Research, 5(4), 460. doi:10.5424/sjar/2007054-269Palau-Salvador, G., GonzĂĄlez-Altozano, P., & Arviza-Valverde, J. (2007). Three-Dimensional Modeling and Geometrical Influence on the Hydraulic Performance of a Control Valve. Journal of Fluids Engineering, 130(1). doi:10.1115/1.2813131Reader-Harris, M. ., Brunton, W. ., Gibson, J. ., Hodges, D., & Nicholson, I. . (2001). Discharge coefficients of Venturi tubes with standard and non-standard convergent angles. Flow Measurement and Instrumentation, 12(2), 135-145. doi:10.1016/s0955-5986(01)00007-3Singhal, A. K., Athavale, M. M., Li, H., & Jiang, Y. (2002). Mathematical Basis and Validation of the Full Cavitation Model. Journal of Fluids Engineering, 124(3), 617-624. doi:10.1115/1.1486223Sun, Y., & Niu, W. (2012). Simulating the Effects of Structural Parameters on the Hydraulic Performances of Venturi Tube. Modelling and Simulation in Engineering, 2012, 1-7. doi:10.1155/2012/458368Teruel, B. J. (2010). Controle automatizado de casas de vegetação: variĂĄveis climĂĄticas e fertigação. Revista Brasileira de Engenharia AgrĂcola e Ambiental, 14(3), 237-245. doi:10.1590/s1415-43662010000300001Vortmann, C., Schnerr, G. H., & Seelecke, S. (2003). Thermodynamic modeling and simulation of cavitating nozzle flow. International Journal of Heat and Fluid Flow, 24(5), 774-783. doi:10.1016/s0142-727x(03)00003-1Wei, Q., Shi, Y., Dong, W., Lu, G., & Huang, S. (2006). Study on hydraulic performance of drip emitters by computational fluid dynamics. Agricultural Water Management, 84(1-2), 130-136. doi:10.1016/j.agwat.2006.01.016Xing, T., & Frankel, S. H. (2002). Effect of Cavitation on Vortex Dynamics in a Submerged Laminar Jet. AIAA Journal, 40(11), 2266-2276. doi:10.2514/2.1563Yeoh, G. H., Liu, C., Tu, J., & Timchenko, V. (2012). Computational Fluid Dynamics and Its Applications 2012. Modelling and Simulation in Engineering, 2012, 1-2. doi:10.1155/2012/61061
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
Gas exchange and leaf contents in bell pepper under energized water and biofertilizer doses
ABSTRACT The objective of this study was to evaluate the effect of energized water and bovine biofertilizer doses on the gas exchange and NPK contents in leaves of yellow bell pepper plants. The experiment was conducted at the experimental area of the Federal University of CearĂĄ, in Fortaleza-CE, Brazil, from June to November 2011. The experiment was set in a randomized block design, in a split-plot scheme; the plots were composed of treatments with energized and non-energized water and the subplots of five doses of liquid biofertilizer (0, 250, 500, 750 and 1000 mL plant-1 week-1). The following variables were analyzed: transpiration, stomatal conductance, photosynthesis and leaf contents of nitrogen (N), phosphorus (P) and potassium (K). Water energization did not allow significant increases in the analyzed variables. The use of biofertilizer as the only source of fertilization was sufficient to provide the nutrients N, P and K at appropriate levels for the bell pepper crop
Adubação potåssica aplicada por fertirrigação e pelo método convencional na cultura do amendoim
Com este trabalho objetivou-se avaliar doses de potĂĄssio aplicadas via fertirrigação por gotejamento e de forma convencional sobre a produtividade do amendoim. O experimento foi conduzido em campo, em Argissolo Vermelho Amarelo, em Fortaleza, CearĂĄ. O delineamento experimental utilizado foi o de blocos ao acaso em esquema fatorial com tratamento adicional [(3 x 2) + 1] e quatro repetiçÔes, sendo estudados os fatores doses de K (D1 - 25, D2 - 50 e D3 - 100 kg ha-1) e duas formas de aplicação (F1 - Fertirrigada e F2 - Convencional) e um tratamento adicional (controle). Aos 90 dias apĂłs a semeadura foi realizada a colheita retirando-se, ao acaso, 5 plantas Ășteis da linha central de cada tratamento, em cada bloco. As plantas foram separadas por tratamento e acondicionadas em estufa telada por cinco dias para a secagem das vagens. As variĂĄveis avaliadas foram: nĂșmero de frutos por planta, massa de vagem, produtividade, massa de 100 sementes e tamanho de vargem. A dose de potĂĄssio aplicada de forma fertirrigada, que maximizou a produtividade (1.530,68 kg ha-1) da cultura do amendoim foi estimada em 69,39 kg ha-1 de K2O e, se aplicada pelo mĂ©todo convencional, em 65,80 kg de K2O, proporcionaria uma produtividade mĂĄxima estimada em 1.092,22 kg ha-1
Production and yield response factor of sunflower under different irrigation depths
ABSTRACT Local information about irrigation depths for sunflower can be used in the design of projects and irrigation management to increase crop yield and to reduce costs. This study aimed to evaluate the effects of irrigation depths on sunflower and calculate its yield response factor. The experiment was conducted in Fortaleza-CE, Brazil, in a randomized block design, with six treatments, four replicates and ten evaluated plants per plot. The treatments were applied in the phenological stages II, III and IV with irrigation depths equivalent to 25, 50, 75, 100, 125 and 150% of crop evapotranspiration. The yield response factor was calculated according to FAO Bulletin nÂș 33. The water supply, equivalent to 79.7 and 91.1% of crop evapotranspiration, increased capitulum mass (43.8 g) and commercial yield of seeds (3,360.2 kg ha-1). Additionally, the yield response factor indicated that sunflower is tolerant to daily irrigation under controlled water deficit