1 resultado para IT value
em Repositório Institucional da Universidade de Aveiro - Portugal
Filtro por publicador
- JISC Information Environment Repository (1)
- Repository Napier (1)
- Abertay Research Collections - Abertay University’s repository (2)
- Academic Archive On-line (Karlstad University; Sweden) (4)
- Academic Archive On-line (Stockholm University; Sweden) (1)
- Academic Research Repository at Institute of Developing Economies (3)
- Acceda, el repositorio institucional de la Universidad de Las Palmas de Gran Canaria. España (1)
- AMS Campus - Alm@DL - Università di Bologna (1)
- AMS Tesi di Dottorato - Alm@DL - Università di Bologna (10)
- AMS Tesi di Laurea - Alm@DL - Università di Bologna (2)
- Aquatic Commons (10)
- ArchiMeD - Elektronische Publikationen der Universität Mainz - Alemanha (3)
- Archimer: Archive de l'Institut francais de recherche pour l'exploitation de la mer (1)
- Archive of European Integration (5)
- Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco (6)
- Aston University Research Archive (50)
- Biblioteca Digital - Universidad Icesi - Colombia (1)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (8)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP) (3)
- Bioline International (1)
- Blue Tiger Commons - Lincoln University - USA (1)
- BORIS: Bern Open Repository and Information System - Berna - Suiça (19)
- Boston University Digital Common (2)
- Brock University, Canada (6)
- Bucknell University Digital Commons - Pensilvania - USA (2)
- Bulgarian Digital Mathematics Library at IMI-BAS (2)
- CaltechTHESIS (2)
- Cambridge University Engineering Department Publications Database (15)
- CentAUR: Central Archive University of Reading - UK (45)
- Chinese Academy of Sciences Institutional Repositories Grid Portal (5)
- Clark Digital Commons--knowledge; creativity; research; and innovation of Clark University (1)
- Cochin University of Science & Technology (CUSAT), India (4)
- Comissão Econômica para a América Latina e o Caribe (CEPAL) (8)
- CORA - Cork Open Research Archive - University College Cork - Ireland (4)
- Corvinus Research Archive - The institutional repository for the Corvinus University of Budapest (12)
- Dalarna University College Electronic Archive (3)
- Deakin Research Online - Australia (92)
- DI-fusion - The institutional repository of Université Libre de Bruxelles (2)
- Digital Archives@Colby (1)
- Digital Commons @ DU | University of Denver Research (1)
- Digital Commons at Florida International University (7)
- Digital Repository at Iowa State University (4)
- DigitalCommons@The Texas Medical Center (5)
- DigitalCommons@University of Nebraska - Lincoln (2)
- Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland (7)
- Duke University (8)
- eResearch Archive - Queensland Department of Agriculture; Fisheries and Forestry (6)
- FUNDAJ - Fundação Joaquim Nabuco (2)
- Glasgow Theses Service (2)
- Greenwich Academic Literature Archive - UK (2)
- Helda - Digital Repository of University of Helsinki (41)
- Illinois Digital Environment for Access to Learning and Scholarship Repository (1)
- Indian Institute of Science - Bangalore - Índia (12)
- Instituto Politécnico de Leiria (1)
- Instituto Politécnico de Viseu (2)
- Instituto Politécnico do Porto, Portugal (1)
- Instituto Superior de Psicologia Aplicada - Lisboa (1)
- Laboratório Nacional de Energia e Geologia - Portugal (1)
- Massachusetts Institute of Technology (3)
- Memoria Académica - FaHCE, UNLP - Argentina (6)
- National Center for Biotechnology Information - NCBI (1)
- Open University Netherlands (1)
- Plymouth Marine Science Electronic Archive (PlyMSEA) (1)
- Publishing Network for Geoscientific & Environmental Data (1)
- QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast (29)
- Queensland University of Technology - ePrints Archive (270)
- RCAAP - Repositório Científico de Acesso Aberto de Portugal (1)
- RDBU - Repositório Digital da Biblioteca da Unisinos (1)
- Repositório Aberto da Universidade Aberta de Portugal (1)
- Repositório Científico da Universidade de Évora - Portugal (4)
- Repositório digital da Fundação Getúlio Vargas - FGV (21)
- Repositório do Centro Hospitalar de Lisboa Central, EPE - Centro Hospitalar de Lisboa Central, EPE, Portugal (1)
- Repositório do ISCTE - Instituto Universitário de Lisboa (1)
- Repositório Institucional da Universidade de Aveiro - Portugal (1)
- Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho" (20)
- Research Open Access Repository of the University of East London. (1)
- RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal (16)
- SAPIENTIA - Universidade do Algarve - Portugal (3)
- Universidad de Alicante (3)
- Universidad del Rosario, Colombia (1)
- Universidad Politécnica de Madrid (10)
- Universidade Complutense de Madrid (1)
- Universidade Técnica de Lisboa (4)
- Universitat de Girona, Spain (2)
- Universitätsbibliothek Kassel, Universität Kassel, Germany (4)
- Université de Lausanne, Switzerland (1)
- Université de Montréal, Canada (3)
- University of Connecticut - USA (2)
- University of Michigan (1)
- University of Queensland eSpace - Australia (6)
- University of Southampton, United Kingdom (1)
- University of Washington (4)
- WestminsterResearch - UK (6)
Resumo:
The main purpose of this thesis is to investigate the potential of ionic liquids (ILs) as a new class of extractive solvents for added-value products from biomass. These include phenolic compounds (vanillin, gallic, syringic and vanillic acids), alkaloids (caffeine) and aminoacids (L-tryptophan). The interest on these natural compounds relies on the wide variety of relevant properties shown by those families and further application in the food, cosmetic and pharmaceutical industries. Aiming at developping more benign and effective extraction/purification techniques than those used, a comprehensive study was conducted using aqueous biphasic systems (ABS) composed of ILs and inorganic/organic salts. In addition, ILs were characterized by a polarity scale, using solvatochromic probes, aiming at providing prior indications on the ILs affinity for particular added-value products. Solid-liquid (S-L) extractions from biomass and using aqueous solution of ILs were also investigated. In particular, and applying and experimental factorial design to optimize the operational conditions, caffeine was extracted from guaraná seeds and spent coffee. With both types of extractions it was found that it is possible to recover the high-value compounds and to recycle the IL and salt solutions. Finally, aiming at exploring the recovery of added-value compounds from biomass using a simpler and more suistainable technique, the solubility of gallic acid, vanillin and caffeine was studied in aqueous solutions of several ILs and common salts. With the gathered results it was possible to demonstrate that ILs act as hydrotropes and that water can be used as an adequate antisolvent. This thesis describes the use of ILs towards the development of more effective and sustainable processes.