Experimental study of the effect of nozzle geometry on the performance of direct-injection diesel sprays for three different fuels

This thesis studies the influence of internal nozzle flow characteristics over a large spectrum of experimental conditions and diagnostics. Experiments were carried out for two nozzle geometries---cylindrical and conical single hole nozzles---and three different fuels. Two of the fuels are pure components---n-heptane and n-dodecane---while the third fuel consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. Measurements include a complete hydraulic characterization consisting of instantaneous injection rate and spray momentum flux measurements; a high-speed visualization of isothermal liquid spray; a high-speed visualization of the evaporative inert spray, imaging liquid and vapor phases simultaneously and finally, a high-speed visualization of the high temperature reactive spray, imaging vapor phase and OH* chemiluminescence for each injection event. All high-temperature diagnostics were performed in a continuous flow test chamber that allows an accurate control on a wide range of thermodynamic conditions (up to 1000 K and 15 MPa). The experimental findings from this work, and the large database obtained (available for download at: http://www.cmt.upv.es/DD01.aspx), could be used to validate CFD models that could help the community understand the fundamental driving mechanisms behind these observations.En esta tesis se estudia la influencia del flujo interno sobre un amplio espectro de condiciones y diagnósticos experimentales. Se realizaron experimentos para dos geometrías de tobera---toberas cilíndrica y cónica de un único orificio---y tres combustibles. Dos de los combustibles son puros---n-heptano y n-dodecano--- mientras el tercero es un combustible sustituto que consiste en una mezcla de tres componentes que busca representar mejor las propiedades físicas y químicas del diesel. Las medidas incluyen una caracterización hidráulica completa, compuesta por tasa de inyección y cantidad de movimiento instantáneas; una visualización de alta velocidad del chorro líquido isotermo; una visualización de alta velocidad del chorro inerte evaporativo, con captura simultánea de las fases líquida y vapor y, finalmente, una visualización del chorro reactivo a alta temperatura, con captura de la fase vapor y la quimioluminiscencia del radical OH* para cada evento de inyección. Todos los diagnósticos en condiciones de alta temperatura fueron realizados en una maqueta de alta presión y temperatura de flujo constante que permite controlar con precisión un rango amplio de condiciones termodinámicas (hasta 1000 K y 15 MPa). Los resultados experimentales y la gran base de datos obtenida en este trabajo (disponible en: http://www.cmt.upv.es/DD01.aspx), podrían ser utilizados para validar modelos CFD detallados que podrían ayudar a la comunidad científica a entender mejor los mecanismos fundamentales que producen los resultados observados.Aquesta tesi estudia la influència del flux intern sobre un gran espectre de condicions i diagnòstics experimentals. Es van realitzar experiments per a dos geometries de tovera---toveres ci¿líndrica i cónica amb un únic orifici---i tres combustibles. Dos dels combustibles són purs---n-heptà i n-dodecà--- mentre el tercer combustible consisteix en una mescla de tres components que formen un combustible substitut que busca representar millor les propietats físiques i químiques del dièsel. Les mesures inclouen una caracterització hidràulica completa, composta per taxa d'injecció i quantitat de moviment instantanis; visualització d'alta velocitat del doll líquid isoterme; visualització d'alta velocitat del doll inert evaporatiu, capturant simultàniament les fases líquid i vapor i, finalment, una visualització del doll reactiu a alta temperatura, capturant la fase vapor i la quimioluminiscència del radical OH per a cada esdeveniment d'injecció. Tots els diagnòstics en condicions d'alta temperatura van ser realitzats en una insta¿lació d'alta pressió i temperatura amb flux constant que permet controlar amb precisió un ampli rang de condicions termodinàmiques (fins a 1000 K i 15 MPa). Els resultats experimentals i la gran base de dades obtinguda en aquest treball (disponible a la web en: http://www.cmt.upv.es/dd01.aspx), podrien ser utilitzats per tal de validar models CFD detallats que podrien ajudar a la comunitat científica a entendre millor els mecanismes fonamentals que produeixen aquestes observacions.Viera Sotillo, JP. (2017). Experimental study of the effect of nozzle geometry on the performance of direct-injection diesel sprays for three different fuels [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/81857TESI

Topological Properties and Dynamic Programming Approach for Designing the Access Network

A wide area network (WAN) can be considered as a set of sites and a set of communication lines that interconnect the sites. Topologically a WAN is organized in two levels: the backbone network and the access network composed of a certain number of local access networks. Each local access network usually has a treelike structure, rooted at a single site of the backbone and connected users (terminal sites) either directly to this backbone site or to a hierarchy of intermediate concentrator sites which are connected to the backbone site. The backbone network has usually a meshed topology, and this purpose is to allow efficient and reliable communication between the switch sites that act as connection points for the local access networks. This work tackled the problem of designing the Access Network Design Problem (ANDP). Only the construction costs, e.g., the costs of digging trenches and placing a fiber cable into service, are considered here. Different results related to the topological structure of the ANDP solutions are studied. Given the complexity of the ANDP (the problem belongs to the NP-hard class), recurrences to solve it are proposed which are based on Dynamic Programming and Dynamic Programming with State-Space Relaxation methodology

A Survivable and Reliable Network Topological Design Model

This work is focused on the resolution of a mixed model for the design of large-sized networks. An algorithm is introduced, whose initial outcomes are promising in terms of topological robustness regarding connectivity and reliability. The algorithm combines the network survivability and the network reliability approaches. The problem of the topological design has been modeled based on the generalized Steiner problem with node-connectivity constraints (GSPNC), which is NP-hard. The aim of this study is to heuristically solve the GSP-NC model by designing low-cost highly connected topologies and to measure the reliability of such solutions with respect to a certain prefixed lower threshold. This research introduces a greedy randomized algorithm for the construction of feasible solutions for the GSP-NC and a local search algorithm based on the variable neighborhood search (VNS) method, customized for the GSP-NC. In order to compute the built network reliabilities, this work adapts the recursive variance reduction (RVR) technique, as a simulation method since the exact evaluation of this measurement is also NP-hard. The experimental tests were performed over a wide set of testing cases, which contained heterogeneous topologies, including instances of more than 200 nodes. The computational results showed highly competitive execution times, achieving minimal local optimal solutions of good quality fulfilling the imposed survivability and reliability conditions

Creación de un restaurante de cocina fusión Asiática en la Isla de San Cristóbal-Galápagos Creación de un restaurante de cocina Tex-Mex para las universidades de la ciudad de Quito.

El motivo de creación de la empresa, se debe a que en la localidad de La Isla San Cristóbal, es un lugar turístico y las opciones o variedad para el turista dentro de restaurantes o variedad de comida es limitada, además la creación de esta es dar a conocer el estilo de cocina sana al turista ya sea extranjero, nacional o de la propia localidad dando así más amplitud a la hora de seleccionar un lugar para comer o compartir

The effect of nozzle geometry over ignition delay and flame lift-off of reacting direct-injection sprays for three different fuels

[EN] The influence of internal nozzle flow characteristics over ignition delay, and flame lift-off of reacting direct-injection sprays is studied experimentally for three fuels using two different nozzle geometries. This is a continuation of previous work by the authors, where, evaporative and non-evaporative, isothermal spray developments were studied experimentally for the same nozzle geometries and fuels. Current study reports the ignition delay through Schlieren technique, and flame lift-off length through OH* chemiluminescence visualization. The nozzle geometries consist of a conical nozzle and a cylindrical nozzle with 8.6% larger outlet diameter when compared to the conical nozzle. The three fuels considered are n-heptane, n-dodecane and a three-component surrogate to better represent the physical and chemical properties of diesel fuel. Reacting spray is found to penetrate faster than non-reacting spray due to combustion induced acceleration after ignition. Higher oxygen concentration, and ambient temperature enhance the reactivity leading to higher spray tip penetration. Injection pressure does not affect the reactivity significantly and hence, influences spray penetration through momentum-similar to a non-reacting spray. Both ignition delay and lift-off length are found to be shortest and longest for n-dodecane and n-heptane, respectively, while the surrogate fuel falls in-between the two pure component fuels. Both ignition delay and lift-off length are found to decrease with increase in oxygen concentration, ambient temperature, and density. The cylindrical nozzle, in spite of shorter lift-off length is found to have longer ignition delay, when compared to the conical nozzle. This could be due to better atomization leading to larger spread angle and evaporative cooling from the cylindrical nozzle compared to a conical nozzle. The longer ignition delay also leads to leaner equivalence ratios at the time of ignition. (C) 2017 Elsevier Ltd. All rights reserved.This work was sponsored by Ministerio de Economia y Competitividad of the Spanish Government in the frame of the Project "Estudio de la interaccion chorro-pared en condiciones realistas de motor", Reference TRA2015-67679-c2-1-R. Additionally, the employed nozzles and Diesel surrogate were provided and defined by GM R&D.Payri, R.; Viera-Sotillo, JP.; Gopalakrishnan, V.; Szymkowicz, P. (2017). The effect of nozzle geometry over ignition delay and flame lift-off of reacting direct-injection sprays for three different fuels. Fuel. 199:76-90. https://doi.org/10.1016/j.fuel.2017.02.075S769019

High resolution mass spectrometry (HRMS) determination of drugs in wastewater and wastewater based epidemiology in Cadiz Bay (Spain)

Multi-residue methods for the determination of the myriad of compounds of emerging concern (CECs) entering in the environment are key elements for further assessment on their distribution and fate. Here, we have developed an analytical protocol for the simultaneous analysis of 195 prescription, over-the-counter, and illicit drugs by using a combination of solid phase extraction (SPE) and determination by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The method was applied to the analysis of influent sewage samples from 3 wastewater treatment plants (WWTPs) from Cadiz Bay (SW Spain), enabling the quantification of more than 100 pharmaceuticals, 19 of them at average concentrations higher than 1 μg L−1, including caffeine (92 μg L−1), paracetamol (72 μg L−1), and ibuprofen (56 μg L−1), as well as several illicit drugs (e.g., cocaine). Wastewater based epidemiology (WBE) was applied for 27 of the detected compounds to establish their consumption in the sampling area, which has been never attempted before. Caffeine, naproxen, and salicylic acid stood out because of their high consumption (638, 51, and 20 g d−1·1000pop−1, respectively). Regarding illicit drugs, cocaine showed the highest frequency of detection and we estimated an average consumption of 3683 mg d−1·1000pop−1 in Cadiz Bay. The combination of new HRMS methods, capable of discriminating thousands of chemicals, and WBE will allow for a more comprehensive characterization of chemical substances and their consumption in urban environments in the near future.The authors thank the staff from JF, CA and PR WWTPs for their assistance during sampling. This research was funded by Junta de Andalucía (ref. FEDER-UCA18-107036) through the FEDER Andalucía 2014-20 program

A Multi-Tree Committee to Assist Port-of-entry Inspection Decisions

A natural way to avoid the injection of potentially dangerous or illicit products in a certain country is by means of protection, following a strict portof- entry inspection policy. A naive exhaustive manual inspection is the most secure policy. However, the number of within containers allows only to check a limited number of containers by day. As a consequence, a smart port-ofentry selection policy must trade cost of inspection with security, in order to fit into the dynamic operation of a port. We explore the design of port-of-entry container inspection policies with imperfect information (unavailable or untrusted data). Starting from an a-priori classification provided by port-of-entry customs operator, a combinatorial optimization problem is introduced. The goal is to match an a-priori container classification with a logically coherent one, subject to a given level of container inspection. Inspired in the related literature, a novel Multi-Tree committee is introduced in order to find a solution to the previous combinatorial problem. It combines the strength of binary decision trees and minimization of logical functions. The algorithm is easy-to-handle and useful for an on-line production. We highlight the effectiveness of our proposal, regarding real traces available from the port of Montevideo. The results show the capability to detect the most risky containers and its conservative nature, respecting any desired level of inspection

The effect of nozzle geometry over the evaporative spray formation for three different fuels

[EN] The influence of internal nozzle flow characteristics over the evaporative spray development is studied experimentally for two different nozzle geome-tries and three different fuels. This is a continuation of previous work by the authors where non-evaporative isothermal spray development was stud-ied experimentally for the same nozzle geometries and fuels. Current study reports macroscopic spray characteristics by imaging the liquid and vapor phases of the spray simultaneously using independent cameras and optical techniques. The liquid phase is captured by a fast-pulsed diffused back illumination setup, while the vapor phase is captured by a single-pass Schlieren setup with diaphragm. The nozzle geometries consist of a conical nozzle and a cylindrical nozzle with 8.6 % larger outlet diameter when compared to the conical nozzle. Among the three fuels, two are pure components n-heptane and n-dodecane while the third consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. For a fixed ambient density, the liquid penetration is controlled by ambient temperature while the vapor penetration is controlled by injection pressure. The cylindrical nozzle, in spite of higher mass flow rate and momentum flux,shows slower vapor spray tip penetration when compared to the conical noz-zle. Also, the cylindrical nozzle consistently produced shorter liquid lengths. The vapor spray spreading angle is found to be inversely proportional to the spray tip penetration, largely influenced by the nozzle geometry and the am-bient density. n-Heptane spray shows the shortest liquid lengths, followed by n-dodecane and finally the Surrogate. No significant difference in vapor penetration rates was found between fuels, confirming that the vapor spray is controlled by momentum, which is independent of fuel. This was not the case for the non-evaporative isothermal sprays previously studied by the au-thors. Liquid lengths show the expected responses to parametric variations of ambient temperature and density. Two empirical predictive models are presented and utilized to analyze the influence of fuel properties on the liq-uid length. The primary factor controlling the liquid length between fuels is found to be their volatility. Finally, the cylindrical nozzle exhibits larger line-of-sight contour fluctuations in both the liquid and vapor phases, which in turn contributes to the shorter liquid lengths and slower vapor penetration.This work was sponsored by Ministerio de Economía y Competitividad of the Spanish Government in the frame of the Project “Estudio de la interaccin chorro-pared en condiciones realistas de motor”, Reference TRA2015-67679-c2-1-R. Additionally, the employed nozzles and Diesel surrogate were provided and defined by GM R&D. The authors would like to thank José Enrique Del Rey and María del Carmen Tomás for their collaboration in the setup of the experiments and laboratory work, and Guillermo Miró for his help measuring fuel properties.Payri, R.; Viera-Sotillo, JP.; Gopalakrishnan, V.; Szymkowicz, P. (2017). The effect of nozzle geometry over the evaporative spray formation for three different fuels. Fuel. 188:645-660. https://doi.org/10.1016/j.fuel.2016.10.064S64566018

The effect of nozzle geometry over internal flow and spray formation for three different fuels

The influence of internal nozzle flow characteristics over macroscopic spray development is studied experimentally for two different nozzle geometries and three fuels. The measurements include a complete hydraulic characterization consisting of instantaneous injection rate and spray momentum flux measurements, followed by a high-speed visualization of isothermal liquid spray in combination with cylindrical and conical nozzle configurations. Two of the fuels are pure components n-heptane and n-dodecane while the third fuel consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. The cylindrical nozzle with 8.6 % larger diameter, in spite of higher mass flow rate and momentum flux, shows slower spray tip penetration when compared to the conical nozzle. The spreading angle is found to be inversely proportional to the spray tip penetration. The spreading angle is largely influenced by the nozzle geometry and the ambient density. Rail pressure was found to have weak influence on the near-field spreading angle and no influence on the standard deviation of the spreading angle. n-Heptane spray shows slowest penetration rates while n-dodecane and the surrogate fuel mixture show very similar spray behavior for variations in injection pressure and back pressure. However, the surrogate fuel mixture shows higher penetration than n-dodecane when using the conical nozzle and lower penetration than n-dodecane when using cylindrical nozzle.This work was sponsored by Ministerio de Economia y Competitividad of the Spanish Government in the frame of the Project "Estudio de la interaccin chorro-pared en condiciones realistas de motor", Reference TRA2015-67679-c2-1-R. Additionally, the employed nozzles and diesel surrogate were provided and defined by GM R&D.Payri Marín, R.; Viera Sotillo, JP.; Gopalakrishnan, V.; Szymkowicz, PG. (2016). The effect of nozzle geometry over internal flow and spray formation for three different fuels. Fuel. 183:20-33. doi:10.1016/j.fuel.2016.06.041S203318

Anticancer Effect of Moringa oleifera Leaf Extract in Human Cancer Cell Lines

Many medicinal plants are used as chemo preventives and antitumor agents in numerous experimental models of carcinogenesis. Moringa oleifera is a plant that contains several phytochemicals, which have been used for medical purposes including anti-inflammatory, analgesic, metabolism activator, anti-asthmatic, anti-anemia, hormone-producing, liver protector, and detoxifier, among others. Moringa oleifera extracts have also been proposed as potential anticancer agents. Cancer is one of the main causes of deaths worldwide. Although many drugs exist against several types of cancer, more specific agents with lower side effects are necessary. Few reports exist regarding the antitumor activity of Moringa oleifera leaf extract in cancer cells. We investigated the effect of Moringa oleifera leaf extract in ovarian, prostate and breast human cancer cell lines. We hypothesized that the Moringa oleifera leaf extract will inhibit the growth of cancer cells. The Moringa oleifera extract was tested in ovarian, prostate and breast cancer cell lines. Seventy-two hours post-treatment, the cell viability was measured by a colorimetric analysis with the AlamarBlue dye. The concentration inhibiting 50% of cell growth (IC50) was calculated. The IC50 of Moringa oleifera extract in the cisplatin-resistant ovarian cancer cells, A2780CP20, was 0.27 mg/ml. The IC50 for the prostate cancer cells, PC3, was 0.17 mg/ml. Current experiments are testing the effect of Moringa oleifera extract in breast, and other ovarian cancer cells