| 61. |
- A. da Cruz, Marcia Gabriely, et al.
(författare)
-
On the product selectivity in the electrochemical reductive cleavage of 2-phenoxyacetophenone, a lignin model compound
- 2022
-
Ingår i: Green Chemistry Letters and Reviews. - : Informa UK Limited. - 1751-8253 .- 1751-7192. ; 15:1, s. 151-159
-
Tidskriftsartikel (refereegranskat)abstract
- Research towards the production of renewable chemicals for fuel and energy industries has found lignin valorization as key. With a high carbon content and aromaticity, a fine-tuning of the depolymerization process is required to convert lignin into valuable chemicals. In context, model compounds have been used to understand the electrocatalyzed depolymerization for mimicking the typical linkages of lignin. In this investigation, 2-phenoxyacetophenone, a model compound for lignin beta-O-4 linkage, was electro-catalytically hydrogenated (ECH) in distinct three-electrode setups: an open and a membrane cell. A deep eutectic solvent based on ethylene-glycol and choline chloride was used to pursue sustainable routes to dissolve lignin. Copper was used as electrocatalyst due to the economic feasibility and low activity towards hydrogen evolution reaction (HER), a side reaction of ECH. By varying the cell type, we demonstrate a simple ECH route for the generation of different monomers and oligomers from lignin. Gas chromatography of the products revealed a higher content of carbonyl groups in those using the membrane cell, whereas the open cell produced mostly hydroxyl-end chemicals. Aiming at high value-added products, our results disclose the cell type influence on electrochemical reductive depolymerization of lignin. This approach encompasses cheap transition metal electrodes and sustainable solvents.
|
|
| 62. |
- A. da Cruz, Márcia G., et al.
(författare)
-
Solvent-free synthesis of photoluminescent carbon nanoparticles from lignin-derived monomers as feedstock
- 2023
-
Ingår i: Green Chemistry Letters and Reviews. - 1751-8253 .- 1751-7192. ; 16:1
-
Tidskriftsartikel (refereegranskat)abstract
- Photoluminescent carbon nanoparticles (CNPs), such as carbon dots (CDs), have attracted much attention owing to a unique set of properties, like high and tunable fluorescence. In this way, the use of carbon-rich lignin has been demonstrated to be a sustainable approach to producing a broad range of photoluminescent CNPs. However, the valorization of this complex polyphenol is limited when it comes to green and efficient ways of conversion. In addition, the existing solvothermal approaches using lignin often result in CDs with low photoluminescence, while flammable and/or toxic solvents are employed. Here, we depolymerized technical lignins, i.e. kraft and soda, through electroreductive cleavage in two different sustainable media: deep eutectic solvent and levulinic acid. After depolymerization, lignin-derived monomers were generated, with a predominance of aryl ether and phenolic groups, which were further combined with 1,2-Phenylenediamine to produce N-doped CNPs in a solvent-free approach. Photoluminescent CNPs with varied sizes were generated (5–50 nm), which presented a wide photoluminescence emission, from blue to red, depending on solvent polarity. These results demonstrate a feasible and sustainable route for the solvent-free synthesis of photoluminescent CNPs using lignin-derived monomers as carbon source, which may find applications in a wide range of fields.
|
|
| 63. |
-
A decade of research on school principals : cases from 24 countries
- 2016. - 1
-
Samlingsverk (redaktörskap) (refereegranskat)abstract
- This book provides a unique map of the focus and directions of contemporary research on school leadership since 2000 in 24 countries. Each of these directions has its own particular cultural, educational and policy history. Taken together, the various chapters in the volume provide a rich and varied mosaic of what is currently known and what is yet to be discovered about the roles and practices of principals, and their contributions to the improvement of teaching and the learning and achievement of students. The particular foci and methodological emphases of the research reported illustrate the different phases in the development of educational policies and provision in each country. This collection is an important addition to existing international research that has shown beyond any reasonable doubt that the influence of school principals is second only to that of teachers in their capacity to impact students’ progress and achievement and to promote equity and social justice.
|
|
| 64. |
-
A design of high performance gas sensor array withdiscrete islands of Au catalyst for increasing of ZnO nanowire junctions
- 2013
-
Proceedings (redaktörskap) (refereegranskat)abstract
- In this study, an effective design for growth of ZnO nanowires directly on gas sensor chips is introduced. The design utilizes the dendrite islands of Au catalyst deposited between and on the Pt electrodes for the nanowires to grow on instead of a continuous seed layer or Au film. This lead to an increase of the nanowirenanowire junctions in the devices, as well as a reduction of the leak current that would occur through the mentioned alternative seed layer; resulting in a higher sensitivity. The results showed that the developed gas sensors could be used for monitoring of NO2 at low concentration.
|
|
| 65. |
-
A feminist companion to the posthumanities
- 2018
-
Samlingsverk (redaktörskap) (refereegranskat)abstract
- This companion is a cutting-edge primer to critical forms of the posthumanities and the feminist posthumanities, aimed at students and researchers who want to catch up with the recent theoretical developments in various fields in the humanities, such as new media studies, gender studies, cultural studies, science and technology studies, human animal studies, postcolonial critique, philosophy and environmental humanities. It contains a collection of nineteen new and original short chapters introducing influential concepts, ideas and approaches that have shaped and developed new materialism, inhuman theory, critical posthumanism, feminist materialism, and posthuman philosophy. A resource for students and teachers, this comprehensive volume brings together established international scholars and emerging theorists, for timely and astute definitions of a moving target – posthuman humanities and feminist posthumanities.
|
|
| 66. |
|
|
| 67. |
- A Herrera, I, et al.
(författare)
-
Comparing a multi-linear (STEP) and systemic (FRAM) method for accident analysis
- 2010
-
Ingår i: RELIABILITY ENGINEERING and SYSTEM SAFETY. - London, UK : Elsevier Science B.V., Amsterdam.. - 0951-8320. ; 95:12, s. 1269-1275, s. 19-26
-
Tidskriftsartikel (refereegranskat)abstract
- Accident models and analysis methods affect what accident investigators look for, which contributory factors are found, and which recommendations are issued. This paper contrasts the Sequentially Timed Events Plotting (STEP) method and the Functional Resonance Analysis Method (FRAM) for accident analysis and modelling. The main issue addressed in this paper is the comparison of the established multi-linear method STEP with the new systemic method FRAM and which new insights the latter provides for accident analysis in comparison to the former established multi-linear method. Since STEP and FRAM are based on a different understandings of the nature of accidents, the comparison of the methods focuses on what we can learn from both methods, how, when, and why to apply them. The main finding is that STEP helps to illustrate what happened, involving which actors at what time, whereas FRAM illustrates the dynamic interactions within socio-technical systems and lets the analyst understand the how and why by describing non-linear dependencies, performance conditions, variability, and their resonance across functions.
|
|
| 68. |
|
|
| 69. |
-
A history of emotions, 1200 - 1800
- 2012. - 1
-
Samlingsverk (redaktörskap) (refereegranskat)abstract
- The history of emotions is an expanding field of research. The essays in this collection examine emotional responses to art and music, the role of emotions in contemporary notions of gender and sexuality and theoretical questions as to their use. Bringing together a series of case studies from points across the medieval and early modern periods, the authors in this volume provide fascinating glimpses into human emotional experience across a variety of cultures.
|
|
| 70. |
-
A History of Environmentalism : Local Struggles, Global Histories
- 2014
-
Samlingsverk (redaktörskap) (refereegranskat)abstract
- Think globally, act locally’ has become a call to environmentalist mobilization, proposing a closer connection between global concerns, local issues and individual responsibility. A History of Environmentalism explores this dialectic relationship, with ten contributors from a range of disciplines providing a history of environmentalism which frames global themes and narrates local stories.Each of the chapters in this volume addresses specific struggles in the history of environmental movements, for example over national parks, species protection, forests, waste, contamination, nuclear energy and expropriation. A diverse range of environments and environmental actors are covered, including the communities in the Amazonian Forest, the antelope in Tibet, atomic power plants in Europe and oil and politics in the Niger Delta. The chapters demonstrate how these conflicts make visible the intricate connections between local and global, the body and the environment, and power and nature. A History of Environmentalism tells us much about transformations of cultural perceptions and ways of production and consuming, as well as ecological and social changes. More than offering an exhaustive picture of the entire environmentalist movement, A History of Environmentalism highlights the importance of the experience of environmentalism within local communities. It offers a worldwide and polyphonic perspective, making it key reading for students and scholars of global and environmental history and political ecology.
|
|
