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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modelling and simulation of industrial multistage flash desalination process with exergetic and thermodynamic analysis. A case study of Azzour seawater desalination plant

Almerri, Abdullah H., Al-Obaidi, Mudhar A.A.R., Alsadaie, S., Mujtaba, Iqbal 28 March 2022 (has links)
Yes / Despite the fact of being intensive energy consumption, MSF is a mature technology that characterised by a high production capacity of high-quality water. The multistage flash (MSF) desalination process is one of the prominent thermal desalination used in the industry of seawater desalination to produce high quantity and high quality of freshwater. However, this process consumes large amount of energy and faces thermal limitations due to its high degree of exergy destruction at several units of the process. Therefore, the research of MSF is still existed to elevate the performance indicators and to resolve the concern of high energy consumption. To rectify these limitations, it is important to determine the units responsible in dissipating energy. This study aims to model an industrial MSF process validated against real data and then investigate the exergy destruction and thermodynamic limitations of the process. As a case study, Azzour MSF seawater desalination plant, located in Al Khiran in Kuwait is under the focus. A comprehensive model is developed by analysing several published models. Specifically, the calculation of exergy destruction has embedded both physical and chemical exergies that identified as a strong point of the model developed. As expected, the highest exergy destruction (55.5%) occurs within the heat recovery section followed by the brine heater with exergy destruction of 28.26% of the total exergy destruction. This study identifies the sections of the industrial process that cause the highest energy losses.
2

Aplicación de tecnologías sostenibles para el desarrollo de alimentos nutritivos y saludables dirigidos a mejorar el estado nutricional de la población del departamento del Chocó (Colombia)

Hinestroza Còrdoba, Leidy Indira 17 January 2022 (has links)
Tesis por compendio / [ES] La importancia económica del fruto del lulo, su riqueza nutricional, accesibilidad y el elevado volumen de desperdicio asociado a la escasa industrialización, han provocado que este cultivo sea considerado por el gobierno colombiano como una de las cadenas productivas priorizadas para el desarrollo tecnológico y de innovación. Sobre este cultivo se plantea la siguiente tesis doctoral, que tiene como objetivo general: Desarrollar productos medianamente procesados a partir del fruto del lulo mediante la aplicación de tecnologías sostenibles y/o innovadoras que garanticen la estabilidad de sus compuestos bioactivos y que permitan incluir otros, como los probioticos, de una forma controlada. Los productos irán dirigidos a la población adulta con problemas de obesidad e hipertensión y a la población infantil con problemas de desnutrición del departamento del Chocó (Colombia). La consecución de este objetivo se aborda desde tres enfoques que configuran los tres capítulos en los que se ha estructurado el apartado de resultados: (i) conocer las principales deficiencias de la población infantil, de entre 2 y 5 años, en Quibdó, una de las zonas más desfavorecidas del departamento del Chocó; (ii) determinar la adecuación del fruto de lulo para el desarrollo de alimentos que ayuden a paliar las diferentes formas de malnutrición en la población infantil y adulta. Y establecer las posibilidades de aplicación de tecnologías que garanticen la estabilidad de sus compuestos bioactivos y que permitan incluir otros, como los probióticos; (iii) determinar las características del residuo que pueda generarse a partir del fruto del lulo y proponer un procedimiento que asegure el aprovechamiento integral del mismo. Los resultados del primer capítulo mostraron que, aunque las deficiencias en los principales macronutrientes en la población infantil no son alarmantes, sí que lo es el aporte de fibra y de micronutrientes como las vitaminas A y C y de minerales como el calcio. Esta situación está provocada, principalmente, por la ausencia total de la leche fresca y el escaso consumo de frutas y verduras. El lulo resultó ser, prácticamente, la única fruta que consumen. lo que confirma su elevada accesibilidad y aceptación. Los resultados experimentales del segundo capítulo mostraron el lulo como una fruta con propiedades fisicoquímicas y funcionales ventajosas para el desarrollo de productos alimenticios saludables a partir de recursos autóctonos de la región del Pacífico colombiano. Sus características estructurales permiten la incorporación de protectores, conservantes, compuestos fisiológicamente activos u otros aditivos. El perfil polifenólico obtenido por LC-MS, reveló la presencia de 288 compuestos pertenecientes a diferentes clases fenólicas. Además, el aumento de la presión del tratamiento de HPH incrementó la diversidad de polifenoles del zumo. El zumo de lulo también resultó ser una matriz adecuada para que Lactobacillus reuteri CECT 925 pueda llevar a cabo la fermentación dando lugar a un zumo con potenciales propiedades probióticas. Aunque los niveles de viabilidad fueron mayores en los zumos homogeneizados a 100 MPa y pH 5,5, en todas las muestras se logró una concentración mínima de 107 UFC/mL al final del ensayo, concentración suficiente para que el microorganismo pueda ejercer sus efectos beneficiosos para la salud en el tracto intestinal del huésped. En el último capítulo, se determinó la composición y las propiedades del bagazo resultante de obtener zumo de lulo y se valoraron diferentes procedimientos para realizar un aprovechamiento integral del mismo. Los resultados pusieron de manifiesto que el bagazo de lulo es una materia prima adecuada para obtener un polvo rico en fibra y carotenoides, que podría ser utilizado como ingrediente en la industria alimentaria y también a nivel doméstico. Se mostró un desequilibrio en la proporción entre fibra soluble e insoluble, lo que debería tenerse en cuenta en las aplicaciones posteriores y sobre todo si el producto se utiliza para alimentación infantil. / [CA] La importància econòmica del fruit del lulo, la seua riquesa nutricional, accessibilitat i l'elevat volum de desaprofitament associat a l'escassa industrialització, han provocat que aquest cultiu siga considerat pel govern colombià com una de les cadenes productives prioritzades per al desenvolupament tecnològic i d'innovació. Sobre aquest cultiu es planteja la següent tesi doctoral, que té com a objectiu general: Desenvolupar productes mitjanament processats a partir del fruit del lulo mitjançant l'aplicació de tecnologies sostenibles i/o innovadores que garantisquen l'estabilitat dels seus compostos bioactius i que permeten incloure uns altres, com els probiotics, d'una forma controlada. Els productes aniran dirigits a la població adulta amb problemes d'obesitat i hipertensió i a la població infantil amb problemes de desnutrició del departament del Chocó (Colòmbia). La consecució d'aquest objectiu s'aborda des de tres enfocaments que configuren els tres capítols en els quals s'ha estructurat l'apartat de resultats: (i) Conéixer les principals deficiències de la població infantil, d'entre 2 i 5 anys, en Quibdó, una de les zones més desfavorides del departament del Chocó; (ii) determinar l'adequació del fruit de lulo per al desenvolupament d'aliments que ajuden a pal·liar les diferents formes de malnutrició en la població infantil i adulta. I establir les possibilitats d'aplicació de tecnologies que garantisquen l'estabilitat dels seus compostos bioactius i que permeten inclouren d'altres, com els probiòtics; (iii) determinar les característiques del residu que puga generar-se a partir del fruit del lulo i proposar un procediment que assegure l'aprofitament integral d'aquest. Els resultats del primer capítol mostraren que, encara que les deficiències en els principals macronutrients en la població infantil no són alarmants, sí que ho és l'aportació de fibra i de micronutrients com les vitamines A i C i de minerals com el calci. Aquesta situació está provocada, principalment, per l'absència total de la llet fresca en la dieta i l'escàs consum de fruites i verdures. El lulo resulta ser, pràcticament, l'única fruita que consumeixen. Els resultats experimentals del segon capítol mostraren el lulo com una fruita amb propietats fisicoquímiques i funcionales avantatjoses per al desenvolupament de productes alimentaris saludables a partir de recursos autòctons de la regió del Pacífic colombià. Les seues característiques estructurals permeten la incorporació de protectors, conservants i compostos actius o altres aditius. El perfil polifenòlic obtingut per LC-MS, mostrà la presencia de 288 compostos de diferents naturalesa polifenòlica. A més, l'augment de la presió del tractament de HPH incrementà la diversitat de polifenols del suc. El suc de lulo també va resultar ser una matriu adequada perquè Lactobacillus reuteri CECT 925 puga dur a terme la fermentació donant lloc a un suc amb potencials propietats probiòtiques. Encara que els nivells de viabilitat van ser majors en els sucs homogeneïtzats a 100 MPa i pH 5,5, en totes les mostres es va aconseguir una concentració mínima de 107 UFC/mL al final de la digestió gastrointestinal in vitro, concentració suficient perquè el microorganisme puga exercir els seus efectes beneficiosos per a la salut en el tracte intestinal de l'hoste. En l'últim capítol, es va determinar la composició i les propietats del bagàs resultant d'obtindre suc de lulo i es van valorar diferents procediments per a realitzar un aprofitament integral d'aquest. Els resultats van posar de manifest que el bagàs de lulo és una matèria primera adequada per a obtindre una pols rica en fibra i carotenoids, que podria ser utilitzat com a ingredient en la indústria alimentària i també a nivell domèstic. Es va mostrar un desequilibri en la proporció entre fibra soluble i insoluble, la qual cosa hauria de tindre's en compte en les aplicacions posteriors i sobretot si el producte s'utilitza per l’alimentació infantil. / [EN] The economic importance of the lulo fruit, its nutritional richness, accessibility and the high volume of waste associated with low industrialization, have led the Colombian government to consider this crop as one of the priority production chains for technological development and innovation. The general objective of the following doctoral thesis is to develop moderately processed products from the lulo fruit through the application of sustainable and/or innovative technologies that guarantee the stability of its bioactive compounds and allow the inclusion of others, such as probiotics, in a controlled way. The final products will be aimed at the adult population with obesity and hypertension problems and the child population with malnutrition problems in the department of Chocó (Colombia). The achievement of this objective is approached from three focuses that make up the three chapters in which the results section is structured: (i) To know the main deficiencies of the child population, aged between 2 and 5 years, in Quibdó, one of the most disadvantaged areas of the department of Chocó; (ii) to determine the suitability of the lulo fruit for the development of foods that help to alleviate the different forms of malnutrition in the child and adult population. And to establish the possibilities of applying technologies that guarantee the stability of its bioactive compounds and allow the inclusion of others, such as probiotics; (iii) to determine the characteristics of the residue that can be generated from the lulo fruit and propose a procedure that ensures its integral use. The results of the first chapter showed that, although the deficiencies in the main macronutrients in the child population are not alarming, the deficiencies in fibre and micronutrients such as vitamins A and C and minerals such as calcium are alarming. This situation is mainly caused by the total absence of fresh milk in the diet and the low consumption of fruit and vegetables. Lulo was practically the only fruit consumed. In the second chapter, the experimental results obtained showed lulo as a fruit with advantageous physicochemical and functional properties for the development of healthy food products from indigenous resources of the Colombian Pacific region. Its structural characteristics allow the incorporation of protectants, preservatives, physiologically active compounds, or other additives. The polyphenolic profile obtained by LC-MS revealed the presence of 288 compounds belonging to different phenolic classes. In addition, increasing the pressure of the HPH treatment increased the polyphenol diversity of the juice. Lulo juice also proved to be a suitable matrix for Lactobacillus reuteri CECT 925 to carry out fermentation resulting in a juice with potential probiotic properties. Although viability levels were higher in the juices homogenized at 100 MPa and pH 5.5, a minimum concentration of 107 CFU/mL was achieved in all samples at the end of in vitro gastrointestinal digestion, which is sufficient for the microorganism to exert its beneficial health effects in the host's intestinal tract. In the last chapter, the composition and properties of the bagasse resulting from the production of lulo juice were determined and different procedures for its full utilization were evaluated. The results showed that lulo bagasse is a suitable raw material to obtain a powder rich in fibre and carotenoids, which could be used as an ingredient in the food industry and also at household level. An imbalance in the ratio between soluble and insoluble fibre was shown, which should be considered in subsequent applications and especially if the product is used for baby food. / Al proyecto FORTALECIMIENTO DE ENCADENAMIENTOS PRODUCTIVOS DE LA SUBREGIÓN DEL CHOCÓ – Número BPIN: 2013000100284 financiado por el Fondo de Ciencia Tecnología e Innovación CTel. (MINCIENCIAS) del Sistema General de Regalías de Colombia, con recursos del departamento del Chocó y ejecutado por la Universidad Tecnológica del Chocó “Diego Luis Córdoba”. / Hinestroza Còrdoba, LI. (2021). Aplicación de tecnologías sostenibles para el desarrollo de alimentos nutritivos y saludables dirigidos a mejorar el estado nutricional de la población del departamento del Chocó (Colombia) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/180266 / Compendio
3

Modelo conceitual de identificação e qualificação de risco dedicado a arquitetura residencial que utiliza tecnologias com aproveitamento da energia solar: uma abordagem na sistemografia / A conceptual model for the identification and qualification of risk within residential architecture that uses solar energy technologies: a systemography-based approach

Barretto, Rubia da Eucaristia 25 April 2014 (has links)
A tendência em ampliar o uso das tecnologias com aproveitamento da energia solar no setor residencial traz para os profissionais da área de projeto novos desafios que é o de reestruturar seus modelos de concepção e desenvolvimento de projetos a fim de garantir o comportamento em uso e a eficiência dos sistemas construtivos seguros. O Modelo conceitual de identificação e qualificação de risco proposto foi elaborado a partir da pesquisa de investigação e de desenvolvimento experimental. Foram considerados aspectos relativos às demandas de segurança em uso, construção do conhecimento a partir da sistemografia e a forma de integração desses saberes em um único sistema. O desenvolvimento experimental ocorreu durante o processo de projeto, produção, montagem, uso e operação de um protótipo denominado Ekó House. A metodologia aplicada envolveu quatro fases: Fase 1 - Exploratória - com pesquisas bibliográficas (as tecnologias, normas e práticas de projeto; Fase 2 - Definições - com a escolha da base teórica de apoio ao modelo; Fase 3 - Desenvolvimento - proposições e experimentos e Fase 4 - Teste e consolidação. Para validar o modelo aplicou-se a validação por generalização analítica, ou seja, expandir e generalizar a teoria. O modelo proposto, inovador no âmbito da sistemografia, apoiou-se na Teoria do Sistema Geral: teoria da modelização proposta por LE MOIGNE. Essa teoria trabalha com sistemas complexos e se apoia em processadores, são eles: de operação, informação e decisão que condicionam a integração sistêmica do projeto. Verificou-se durante a aplicação do modelo que ele estimula o aprofundamento das análises das soluções de projeto, quando: a)Identifica e formaliza conceitos que suportam o desenvolvimento das soluções nos diversos sistemas; xv b)Facilita a compreensão e síntese das múltiplas informações que precisam ser compatibilizadas no projeto; c)Formaliza um único principio \"segurança do usuário\" para a lógica de concepção e desenvolvimento de projeto; d)Organiza e permite que se priorizem as informações técnicas [fabricantes e normas];e)Facilita o entendimento por meio de informações as ações de organização e coordenação dos sistemas no espaço e de sua relação com as funcionalidades, uso e estética; e f)Fomenta a busca de soluções mais adequadas a segurança do usuário. Sendo assim, o teste do modelo validou a hipótese. Ele contribui como ferramenta guia de aprimoramento do processo de projeto. / The increasing use of solar energy technologies in the residential sector brings new challenges to professionals who work in the field of design, such as the need to restructure their mindset regarding to the conception and to the development of design, in order to ensure the performance and the efficiency of safe building systems. In this context, this thesis main goal is to propose a conceptual model for the identification and qualification of risk within residential architecture that uses solar energy technologies based on systemography. It\'s an investigative and experimental research, considering aspects related to: meet the demands of safety in use, the knowledge construction and how those could be managed. The experimental development was carried out during the process of design, production, assembly, use and operation of a prototype named Ekó House. The applied method has encompassed four stages: 1) Exploratory - bibliographic research about technologies, codes, rules and design practices; 2) Definitions - the choice of the theoretical basis to ground the model; 3) Development - propositions and experiments and 4) Proofing and consolidation. In order to verify the model it was carried out a test wherewith is possible to perform a validation by analytical generalization, that is, expand and generalize the theory. The proposed model, which represents an innovation in sistemography field, was based on LE MOIGNES\'s Systemic Theory. This Theory enabled the implementation in complex systems, using information, decision and operating processors which condition the design systemic integration. The results obtained by the research show that the model: a) incorporates knowledge, thus, being helpful along the decision-making process; b) eases the understanding and the overview of the diverse information needed by the design; c) formalizes a logic of design conception and development; d) xvii organizes and prioritizes the design technical recommendations [rules and manufacturers]; e) is able to promote an interference in the system\'s organization and coordination in space and also in its relation to functionality and aesthetics; it also f) guides the use of more suitable configurations to the design development. The model presents itself as a tool that is capable of reducing misuse of standards, conflicts between building systems, Technologies and architecture, as well as design failures that compromise safety in use.
4

Modelo conceitual de identificação e qualificação de risco dedicado a arquitetura residencial que utiliza tecnologias com aproveitamento da energia solar: uma abordagem na sistemografia / A conceptual model for the identification and qualification of risk within residential architecture that uses solar energy technologies: a systemography-based approach

Rubia da Eucaristia Barretto 25 April 2014 (has links)
A tendência em ampliar o uso das tecnologias com aproveitamento da energia solar no setor residencial traz para os profissionais da área de projeto novos desafios que é o de reestruturar seus modelos de concepção e desenvolvimento de projetos a fim de garantir o comportamento em uso e a eficiência dos sistemas construtivos seguros. O Modelo conceitual de identificação e qualificação de risco proposto foi elaborado a partir da pesquisa de investigação e de desenvolvimento experimental. Foram considerados aspectos relativos às demandas de segurança em uso, construção do conhecimento a partir da sistemografia e a forma de integração desses saberes em um único sistema. O desenvolvimento experimental ocorreu durante o processo de projeto, produção, montagem, uso e operação de um protótipo denominado Ekó House. A metodologia aplicada envolveu quatro fases: Fase 1 - Exploratória - com pesquisas bibliográficas (as tecnologias, normas e práticas de projeto; Fase 2 - Definições - com a escolha da base teórica de apoio ao modelo; Fase 3 - Desenvolvimento - proposições e experimentos e Fase 4 - Teste e consolidação. Para validar o modelo aplicou-se a validação por generalização analítica, ou seja, expandir e generalizar a teoria. O modelo proposto, inovador no âmbito da sistemografia, apoiou-se na Teoria do Sistema Geral: teoria da modelização proposta por LE MOIGNE. Essa teoria trabalha com sistemas complexos e se apoia em processadores, são eles: de operação, informação e decisão que condicionam a integração sistêmica do projeto. Verificou-se durante a aplicação do modelo que ele estimula o aprofundamento das análises das soluções de projeto, quando: a)Identifica e formaliza conceitos que suportam o desenvolvimento das soluções nos diversos sistemas; xv b)Facilita a compreensão e síntese das múltiplas informações que precisam ser compatibilizadas no projeto; c)Formaliza um único principio \"segurança do usuário\" para a lógica de concepção e desenvolvimento de projeto; d)Organiza e permite que se priorizem as informações técnicas [fabricantes e normas];e)Facilita o entendimento por meio de informações as ações de organização e coordenação dos sistemas no espaço e de sua relação com as funcionalidades, uso e estética; e f)Fomenta a busca de soluções mais adequadas a segurança do usuário. Sendo assim, o teste do modelo validou a hipótese. Ele contribui como ferramenta guia de aprimoramento do processo de projeto. / The increasing use of solar energy technologies in the residential sector brings new challenges to professionals who work in the field of design, such as the need to restructure their mindset regarding to the conception and to the development of design, in order to ensure the performance and the efficiency of safe building systems. In this context, this thesis main goal is to propose a conceptual model for the identification and qualification of risk within residential architecture that uses solar energy technologies based on systemography. It\'s an investigative and experimental research, considering aspects related to: meet the demands of safety in use, the knowledge construction and how those could be managed. The experimental development was carried out during the process of design, production, assembly, use and operation of a prototype named Ekó House. The applied method has encompassed four stages: 1) Exploratory - bibliographic research about technologies, codes, rules and design practices; 2) Definitions - the choice of the theoretical basis to ground the model; 3) Development - propositions and experiments and 4) Proofing and consolidation. In order to verify the model it was carried out a test wherewith is possible to perform a validation by analytical generalization, that is, expand and generalize the theory. The proposed model, which represents an innovation in sistemography field, was based on LE MOIGNES\'s Systemic Theory. This Theory enabled the implementation in complex systems, using information, decision and operating processors which condition the design systemic integration. The results obtained by the research show that the model: a) incorporates knowledge, thus, being helpful along the decision-making process; b) eases the understanding and the overview of the diverse information needed by the design; c) formalizes a logic of design conception and development; d) xvii organizes and prioritizes the design technical recommendations [rules and manufacturers]; e) is able to promote an interference in the system\'s organization and coordination in space and also in its relation to functionality and aesthetics; it also f) guides the use of more suitable configurations to the design development. The model presents itself as a tool that is capable of reducing misuse of standards, conflicts between building systems, Technologies and architecture, as well as design failures that compromise safety in use.
5

Component-led integrative optimisation methodology for avionic thermal management

Jones, Andy January 2017 (has links)
The modern military aircraft can be defined as a System of Systems (SoS); several distinct systems operating simultaneously across boundary interfaces. As the on-board subsystems have become more complex and diverse, the development process has become more isolated. When considering thermal management of distributed heat loads, the aircraft has become a collection of individually optimised components and subsystems, rather than the implementation of a single system to perform a given task. Avionic thermal management is quickly becoming a limiting factor of aircraft performance, reliability and effectiveness. The challenge of avionic thermal management is growing with the increasing complexity and power density of avionic packages. The aircraft relies on a heat rejection growth capacity to accommodate the additional through-life avionic heat loads. Growth capacity is defined as an allowable thermal loading growth designed into the system by the underutilisation of spatial and cooling supply at aircraft introduction; however, this is a limited resource and aircraft subsystem cooling capability is reaching a critical point. The depleted growth capacity coupled with increased avionic power demands has led to component thermal failure. However, due to the poor resolution of existing data acquisition, experimental facilities or thermodynamic modeling, the exact inflight-operating conditions remain relatively unknown. The knowledge gap identified in this work is the lack of definitive methodology to generate high fidelity data of in-flight thermal conditions of fast-jet subsystems and provide evidence towards effective future thermal management technologies. It is shown that, through the development of a new methodology, the knowledge gap can be reduced and as an output of this approach the unknown system behaviour can be defined. A multidisciplinary approach to the replication, analysis and optimisation of a fast-jet TMS is detailed. The development of a new Ground Test Facility (GTF) allows previously unidentified system thermal behaviour to be evaluated at component, subsystem and system level. The development of new data to characterise current thermal performance of a fast jet TMS allows recommendations of several new technologies to be implemented through a component led integrative system optimisation. This approach is to consider the TMS as a single system to achieve a single goal of component thermal management. Three technologies are implemented to optimise avionic conditions through the minimisation of bleed air consumption, improve avionic reliability through increased avionic component isothermalisation and increase growth capacity through improved avionic heat exchanger fin utilisation. These component level technologies improved system level performance. A reduction in TMS bleed air consumption from 1225kg to 510kg was found to complete a typical flight profile. A peak predicted aircraft specific fuel consumption saving of 1.23% is seen at a cruise flight condition because of this approach to avionic thermal management.

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