| 11. |
- A. B. Marçal, L., et al.
(författare)
-
Spatially resolved structural and chemical properties of the white layer in machined Inconel 718 super alloy
- 2024
-
Ingår i: Materials and Design. - 0264-1275. ; 239
-
Tidskriftsartikel (refereegranskat)abstract
- Inconel 718 is one type of nickel-based alloy used for a large range of applications, including gas turbines and aeroengines components. Although mechanical and thermodynamic properties of this material have been deeply studied in the past years, a method able to investigate local properties of the thin white layer formed on the alloy surface after machining remains challenging. Here, a 90 nm X-ray beam is used to probe the local strain, crystal orientation, and chemical composition of grains in the white layer. Data reveals mosaicity induced by the tool during machining. The high spatial resolution, combined with crystal lattice sensitivity, shows that the average grain size is around 30 nm throughout the white layer, while the strain is anisotropic nearest to the surface. Results provide new insights on the basic properties of the white layer in super alloys, revealing important information about the impact of finish machining which might help to explain fatigue and cracking formation on these materials during their usage phase.
|
|
| 12. |
|
|
| 13. |
- A. Bateki, Christian, et al.
(författare)
-
Of milk and mobiles: Assessing the potential of cellphone applications to reduce cattle milk yield gaps in Africa using a case study
- 2021
-
Ingår i: Computers and Electronics in Agriculture. - : Elsevier BV. - 0168-1699. ; 191
-
Tidskriftsartikel (refereegranskat)abstract
- There are growing expectations that Information and Communication Technology (ICT) applications could help improve on-farm yields amongst smallholder farmers in developing countries, and consequently, food and nutrition security. However, few studies have quantified the actual contribution of ICT applications on farmers’ yields, and these studies predominantly focused on crop production. We assessed the potential of ICT applications to close milk yield gaps among small- and medium scale dairy cattle farmers in Africa. First, we developed a theoretical framework summarizing biophysical and socio-economic constraints that foster milk yield gaps and discussed which constraints can be addressed using ICT applications. Second, using a case study of a feeding advice application for dairy cattle pre-tested with farmers in rural Kenya, we analyzed how much stand-alone the application could contribute to close dairy cattle milk yield gaps. Our findings suggest that ICT applications could help address some existing biophysical and socio-economic constraints fostering milk yield gaps, including data collection for breeding programs, feeding management advice, and facilitating access to markets and capital. Our stand-alone ICT application closed yield gaps by 2 % to 6 % on representative farms. Several factors may explain the limited actual contribution of selected ICT applications to reduce existing milk yield gaps, including the quality of the input data and models used in ICT applications, and more structural constraints that cannot be addressed by digital tools. Therefore, although ICT applications could help address constraints to achieving higher milk yields on dairy farms, a significant contribution to improve yields may only be achieved when conditions surrounding their use are adequate.
|
|
| 14. |
|
|
| 15. |
- A, Dell'Isola, et al.
(författare)
-
The role of pain and walking difficulties in shaping willingness to undergo joint surgery for osteoarthritis: Data from the Swedish BOA register
- 2021
-
Ingår i: Osteoarthritis and Cartilage Open. - : Elsevier BV. - 2665-9131. ; 3:2
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate whether the association between pain intensity and willingness to undergo surgery is explained by walking difficulties, in patients with knee or hip osteoarthritis (OA). Methods: This is an observational study using data from the Better management of patients with Osteoarthritis (BOA) register, which collects data from a publicly financed self-management programme for people with OA in Sweden. We included all patients with knee or hip OA who attended the baseline visit between 2008 and 2016. We conducted separate mediation analyses within a counterfactual framework to estimate the mediation effect of walking difficulties (yes/no) on willingness to undergo surgery (yes/no) for each one-point increase in pain (0–10 on a numeric rating scale), adjusted for relevant confounders. Results: We included 72,131 patients (69% women, mean age 66, mean pain 5.4, 81% had walking difficulties, 27% was willing to undergo surgery). A one-point increase in pain intensity was associated with 1.53 (95% CI: 1.51; 1.55) higher odds of being willing to undergo surgery. Walking difficulties mediated 10%–25% of the effect of one-point increase in pain when pain was <8/10, while at pain ≥8/10 this percentage decreased to 3%. Conclusions: More than 80% of the BOA patients have mild to moderate pain (<8/10) and walking difficulties can mediate up to a quarter of the total effect of pain on the willingness to undergo surgery in these patients. Trials to evaluate the potential to lower surgery demand by reducing walking difficulties in people with these characteristics are needed.
|
|
| 16. |
- A. da Cruz, Márcia G., et al.
(författare)
-
Electrochemical Depolymerization of Lignin in a Biomass-based Solvent
- 2022
-
Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 15:15
-
Tidskriftsartikel (refereegranskat)abstract
- Breaking down lignin into smaller units is the key to generate high value-added products. Nevertheless, dissolving this complex plant polyphenol in an environment-friendly way is often a challenge. Levulinic acid, which is formed during the hydrothermal processing of lignocellulosic biomass, has been shown to efficiently dissolve lignin. Herein, levulinic acid was evaluated as a medium for the reductive electrochemical depolymerization of the lignin macromolecule. Copper was chosen as the electrocatalyst due to the economic feasibility and low activity towards the hydrogen evolution reaction. After depolymerization, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy revealed lignin-derived monomers and dimers. A predominance of aryl ether and phenolic groups was observed. Depolymerized lignin was further evaluated as an anti-corrosion coating, revealing enhancements on the electrochemical stability of the metal. Via a simple depolymerization process of biomass waste in a biomass-based solvent, a straightforward approach to produce high value-added compounds or tailored biobased materials was demonstrated.
|
|
| 17. |
- 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.
|
|
| 18. |
- 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.
|
|
| 19. |
|
|
| 20. |
- 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.
|
|
