| 1. |
- Carvalho, Lara, et al.
(författare)
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Alkali enhanced biomass gasification with in situ S capture and a novel syngas cleaning : Part 2: Techno-economic analysis
- 2018
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 165:Part B, s. 471-482
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Tidskriftsartikel (refereegranskat)abstract
- Previous research has shown that alkali addition has operational advantages in entrained flow biomass gasification and allows for capture of up to 90% of the biomass sulfur in the slag phase. The resultant low-sulfur content syngas can create new possibilities for syngas cleaning processes. The aim was to assess the techno-economic performance of biofuel production via gasification of alkali impregnated biomass using a novel gas cleaning systemcomprised of (i) entrained flow catalytic gasification with in situ sulfur removal, (ii) further sulfur removal using a zinc bed, (iii) tar removal using a carbon filter, and (iv) CO2 reductionwith zeolite membranes, in comparison to the expensive acid gas removal system (Rectisol technology). The results show that alkali impregnation increases methanol productionallowing for selling prices similar to biofuel production from non-impregnated biomass. It was concluded that the methanol production using the novel cleaning system is comparable to the Rectisol technology in terms of energy efficiency, while showing an economic advantagederived from a methanol selling price reduction of 2–6 €/MWh. The results showed a high level of robustness to changes related to prices and operation. Methanol selling prices could be further reduced by choosing low sulfur content feedstocks.
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| 2. |
- Carvalho, Lara, et al.
(författare)
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Challenges in small-scale combustion of agricultural biomass fuels
- 2007
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Ingår i: 9th Conference on Energy for a Clean Environment.
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Konferensbidrag (refereegranskat)abstract
- In the present work, several agricultural biomass fuels, namely straw, Miscanthus,maize whole crop and horse manure mixed with two bedding materials, woodshavings and straw, were reviewed in terms of fuel characteristics. Furthermore,these fuels were tested in several existing boiler technologies and the particulateand gaseous emissions were monitored. The ash was analysed visually in terms ofpresence of sintered material. As expected, all the fuels showed problems withash lumping and slag formation, especially straw and horse manure. Differentboiler technologies showed different operational performance regarding ash andslag management. Miscanthus was the best fuel tested regarding emissions. Maizeand horse manure are problematic fuels regarding NOx and particulate emissions.Due to the big variation of the fuel properties and therefore combustion behaviourof agricultural biomass, further R&D is required to adapt the existing small-scalecombustion systems for these new fuels. Improvements in the combustionchamber design, controlling technology and ash removal systems of small-scalecombustion systems are therefore essential.
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| 3. |
- Carvalho, Lara, et al.
(författare)
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Challenges in small-scale combustion of agricultural biomass fuels
- 2008
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Ingår i: International Journal of Energy for a Clean Environment. - 2150-3621 .- 2150-363X. ; 9:1-3, s. 127-142
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Tidskriftsartikel (refereegranskat)abstract
- Straw, Miscanthus, maize, and horse manure were reviewed in terms of fuel characteristics. They were tested in existing boilers, and the particulate and gaseous emissions were monitored. The ash was analyzed for the presence of sintered material. All the fuels showed problems with ash lumping and slag formation. Different boiler technologies showed different operational performances. Maize and horse manure are problematic fuels regarding NOx and particulate emissions. Miscanthus was the best fuel tested. Due to the big variation of fuel properties and therefore combustion behavior of agricultural biomass, further R&D is required to adapt the existing boilers for these fuels.
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| 4. |
- Carvalho, Lara, et al.
(författare)
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Methanol production via black liquor co-gasification with expanded raw material base : Techno-economic assessment
- 2018
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 225, s. 570-584
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Tidskriftsartikel (refereegranskat)abstract
- Entrained flow gasification of black liquor combined with downstream-gas-derived synthesis of biofuels in Kraft pulp mills has shown advantages regarding energy efficiency and economic performance when compared to combustion in a recovery boiler. To further increase the operation flexibility and the profitability of the biofuel plant while at the same time increase biofuel production, black liquor can be co-gasified with a secondary feedstock (blend-in feedstock). This work has evaluated the prospects of producing biofuels via co-gasification of black liquor and different blend-in feedstocks (crude glycerol, fermentation residues, pyrolysis liquids) at different blend ratios. Process modelling tools were used, in combination with techno-economic assessment methods. Two methanol grades, crude and grade AA methanol, were investigated. The results showed that the co-gasification concepts resulted in significant increases in methanol production volumes, as well as in improved conversion efficiencies, when compared with black liquor gasification; 5-11 and 4-10 percentage point in terms of cold gas efficiency and methanol conversion efficiency, respectively. The economic analysis showed that required methanol selling prices ranging from 55-101 €/MWh for crude methanol and 58-104 €/MWh for grade AA methanol were obtained for an IRR of 15%. Blend-in led to positive economies-of-scale effects and subsequently decreased required methanol selling prices, in particular for low cost blend-in feedstocks (prices below approximately 20 €/MWh). The co-gasification concepts showed economic competitiveness to other biofuel production routes. When compared with fossil fuels, the resulting crude methanol selling prices were above maritime gas oil prices. Nonetheless, for fossil derived methanol prices higher than 80 €/MWh, crude methanol from co-gasification could be an economically competitive option. Grade AA methanol could also compete with taxed gasoline. Crude glycerol turned out as the most attractive blend-in feedstock, from an economic perspective. When mixed with black liquor in a ratio of 50/50, grade AA methanol could even be cost competitive with untaxed gasoline.
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| 5. |
- Carvalho, Lara, 1978-
(författare)
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Opportunities to broaden biomass feedstocks in thermochemical conversion technologies
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Global environmental concerns are motivating a growing interest in broadening the biomass feedstock base in several energy sectors, including (i) the domestic heating sector, presently dominated by stem wood combustion, and (ii) biofuel production, presently dominated by edible crops. The objective of this thesis is to investigate new opportunities to broaden the biomass feedstock in thermochemical conversion technologies. The performance of different feedstocks was therefore investigated for (i) heat production in small-scale combustion systems and (ii) biofuel production in large-scale gasification-based plants. The selected feedstocks were agricultural residues, forest wood, pyrolysis liquid and industrial by-products, such as lignin, black liquor, crude glycerol and fermentation residues.The alkali metals content in biomass has an important role in combustion and gasification. Alkali metals can cause ash-related problems in small-scale combustion systems, while they can catalyse gasification reactions thus increasing conversion efficiency. Keeping this effect in mind, the present investigation was based on combustion tests with pelletised agricultural residues (non-woody feedstocks with ash contents of 3-8 wt% on a dry basis) to evaluate their combustion feasibility in several small-scale appliances. Moreover, the potential techno-economic benefits of alkali addition in gasification-based biofuel plants were investigated in two different systems: (i) stand-alone biofuel plant operated with wet-alkali-impregnated forest residues and alkali-rich lignin as well as (ii) biofuel plant integrated with a Kraft pulp mill operated with black liquor (an inherently alkali-rich feedstock) mixed with different blend ratios of pyrolysis liquid, crude glycerol or fermentation residues (co-gasification concept). The techno-economic analysis in large-scale entrained-flow-gasification-based biofuel plants was made with the help of simulation tools.The combustion tests have shown that high alkali feedstocks lead to problems with ash accumulation and slag formation in small-scale appliances. The results indicated that non-woody feedstocks can only be burned in appliances adapted to manage high ash content feedstocks. Effective ash cleaning and enhanced combustion controlling mechanisms are relevant characteristics to have in appliances when using these feedstocks. It has been shown that four out of the seven selected feedstocks can be burned in small-scale appliances, while fulfilling the legal European requirements (EN 303-5:2012) in terms of combustion efficiency and emissions. The nitrogen content and ash composition were shown to be important parameters to evaluate whether a feedstock can be utilised in small-scale combustion appliances.The techno-economic investigations of the gasification-based biofuel plants have shown that alkali impregnation is an attractive option to increase energy performance and downstream biofuel production. The economic assessment has indicated that alkali impregnation does not significantly increase biofuel production costs, while it allows the application of a new syngas cleaning system that can significantly reduce biofuel production costs. The present study has shown that the vi co-gasification concept has also techno-economic benefits as a result of the (i) alkali content in black liquor and (ii) economy-of-scale effects. These benefits can be enhanced by choosing energy-rich and low-cost blend-in feedstocks. The gasification-based biofuel production routes hereby investigated exhibit a good economic performance since biofuel required selling prices were economically competitive with other biofuel production routes as well as with taxed gasoline.
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| 6. |
- Carvalho, Lara, et al.
(författare)
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Performance of a pellet boiler fired with agricultural fuels
- 2013
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 104, s. 286-296
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Tidskriftsartikel (refereegranskat)abstract
- The increasing demand for woody biomass increases the price of this limited resource, motivating the growing interest in using woody materials of lower quality as well as non-woody biomass fuels for heat production in Europe. The challenges in using non-woody biomass as fuels are related to the variability of the chemical composition and in certain fuel properties that may induce problems during combustion. The objective of this work has been to evaluate the technical and environmental performance of a 15 kW pellet boiler when operated with different pelletized biomass fuels, namely straw (Triticum aestivum), Miscanthus (Miscanthus × giganteus), maize (Zea mays), wheat bran, vineyard pruning (from Vitis vinifera), hay, Sorghum (Sorghum bicolor) and wood (from Picea abies) with 5% rye flour. The gaseous and dust emissions as well as the boiler efficiency were investigated and compared with the legal requirements defined in the FprEN 303-5 (final draft of the European standard 303-5). It was found that the boiler control should be improved to better adapt the combustion conditions to the different properties of the agricultural fuels. Additionally, there is a need for a frequent cleaning of the heat exchangers in boilers operated with agricultural fuels to avoid efficiency drops after short term operation. All the agricultural fuels satisfied the legal requirements defined in the FprEN 303-5, with the exception of dust emissions during combustion of straw and Sorghum. Miscanthus and vineyard pruning were the best fuels tested showing comparable emission values to wood combustion.
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| 7. |
- Carvalho, Lara
(författare)
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Small-scale combustion of agricultural biomass fuels
- 2012
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The ambitious targets of the European Union in increasing the use of renewable energies to 20% of Europe’s energy needs, call for urgent changes, including in the biomass sector. The share of solid biomass for heating purposes could be further increased by replacing oil- and gas-fired furnaces with biomass boilers and by expanding the spectrum of biomass raw materials for small-scale combustion systems. The interest in using non-woody biomass fuels for heat production has been increasing in Europe due to two main factors. First, the market for fossil fuels is unstable and their prices are continuously rising. Second, the increase competition for woody biomass between the heating sector and other industries, have increased the price of wood. As a result, the interest for alternative biomass fuels is growing rapidly, covering woody materials of low quality, energy crops and forest residues.The present work aims at investigating the technical feasibility of using non-woody biomass fuels in existing small-scale combustion appliances developed for burning wood. Therefore, combustion tests with different non-woody biomass fuels and in different combustion appliances were performed in standard laboratory conditions and in households under real life conditions (field tests). The laboratory tests were performed using eight different fuels (straw, Miscanthus, maize, vineyard pruning, hay, wheat bran and Sorghum) while in the field tests straw, Miscanthus and maize were burned. The gaseous and particle emissions, the slag tendency and the efficiency of the combustion systems operated with non-woody biomass fuels were analysed and when possible compared with the legal requirements defined in FPrEN 303-5. The limitations of the investigated combustion appliances when operated with non-woody biomass fuels were analysed and discussed.Non-woody biomass fuels could be used for heat production in existing combustion appliances as long as the systems are adapted for burning high ash content fuels. Among the investigated fuels, Miscanthus, vineyard pruning and hay could be burnt in most of the tested combustion appliances while fulfilling the legal European requirements (defined in FprEN303-5) in terms of emissions and efficiency. The non-woody biomass fuels showed problems with ash accumulation and slag formation and could only be burned without unwanted shutdowns in combustion appliances adapted to manage high ash content fuels. Straw, wheat bran and maize were the most problematic fuels regarding slagging. The combustion appliances require appropriate technological developments to manage the strong variability in terms of chemical and thermal properties of the non-woody biomass fuels. The results of the laboratory tests were generally in agreement with the field test results.
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| 8. |
- Carvalho, Lara, et al.
(författare)
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Techno-economic assessment of catalytic gasification of biomass powders for methanol production
- 2017
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 237, s. 167-177
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the techno-economic performance and potential benefits of methanol production through catalytic gasification of forest residues and lignin. The results showed that while catalytic gasification enables increased cold gas efficiencies and methanol yields compared to non-catalytic gasification, the additional pre-treatment energy and loss of electricity production result in small or no system efficiency improvements. The resulting required methanol selling prices (90–130 €/MWh) are comparable with production costs for other biofuels. It is concluded that catalytic gasification of forest residues can be an attractive option as it provides operational advantages at production costs comparable to non-catalytic gasification. The addition of lignin would require lignin costs below 25 €/MWh to be economically beneficial.
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| 9. |
- Carvalho, Sérgio A., et al.
(författare)
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One-year predictors of PTSD symptoms, anxiety, and depression in SARS-CoV-2 survivors : psychological flexibility and major life events as main predictive factors
- 2024
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Ingår i: Frontiers in Psychology. - : Frontiers Media S.A.. - 1664-1078. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: The COVID-19 pandemic held considerable health-related outcomes worldwide, including mental health challenges, with elevated risk of psychiatric sequelae.METHODS: This study aimed to test the longitudinal (1 year) predictive role of psychosocial factors on post-traumatic stress disorder (PTSD), anxiety, and depressive symptoms in SARS-CoV-2 survivors (N = 209 at T1; N = 61; attrition rate 70.83%), through Pearson's correlation analyses and longitudinal multiple regression analyses. Participants (age M = 35.4, SD = 10.1) completed online self-report questionnaires of psychosocial variables, PTSD, anxiety, and depression.RESULTS: Depression and anxiety symptoms were increased, and 42% of survivors presented clinically meaningful PTSD symptoms. PTSD symptoms were longitudinally predicted by having children (β = 0.32, p < 0.01), number of recent major life events (β = 0.34, p < 0.01), and psychological flexibility (β = -0.36, p < 0.01). Number of major life events (β = 0.29, p < 0.05) and psychological flexibility (β = -0.29, p < 0.05) predicted anxiety. Number of recent major life events (β = 0.32, p < 0.01) was the sole predictor of depressive symptoms.DISCUSSION: Psychosocial variables contribute to the long-term harmful effects of the COVID-19 pandemic on psychopathological symptoms. These results suggest that, during the pandemic, mental health was impacted by both socio-contextual factors and individual self-regulatory skills, namely the ability to respond flexibily to contextual cues and guide behavior according to the direct experience. Specifically, results point out the importance of societal incentives to reduce parental burden and socioeconomic losses, as well as to promote adaptive psychological skills such as psychological flexibility.
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| 10. |
- Carvalho, Sérgio A., et al.
(författare)
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Self-as-context and depressive symptoms in the general population : A further analysis of the self experiences questionnaire
- 2022
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Ingår i: Current Psychology. - : Springer. - 1046-1310 .- 1936-4733. ; 41:12, s. 8897-8907
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Tidskriftsartikel (refereegranskat)abstract
- The current study aims to contribute to the psychometric validation of the Self Experiences Questionnaire (SEQ), a measure of self-as-context as conceptualized by Acceptance and Commitment Therapy, and to contribute to a better understanding of the relationship between self-as-context, other psychological flexibility processes, and depressive symptoms. The sample (N = 266; 72.6% women) was obtained through paper-pencil and online collection methods in the general Portuguese population. Confirmatory factor analysis, reliability analyses, and convergent and divergent analyses were conducted. A mediation analysis of the effects of self-as-distinction and self-as-observer on depression symptoms through openness to experience, behavioral awareness, and valued action (while controlling for brooding) was performed using PROCESS. Items 8, 12 and 15 were removed to achieve the best model fit, which resulted in a 12-item final version of the SEQ. This version appears to be a psychometrically valid two-dimensional measure of self-as-distinction and self-as-observer, as well as a one global measure of self-as-context. Results from mediation analyses suggested that the relationship of self-as-observer and self-as-distinction with depressive symptoms is mediated by the ability to be behaviorally aware and to act according to personal values, but not by the ability to be open to experience. The behaviorally-oriented aspects of psychological flexibility seem to have particular importance on the presentation of depressive symptoms. More studies are nonetheless needed to analyze SEQ's structure and validity in order to attain a consensual version of the questionnaire.
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| 11. |
- Clark, Andrew G., et al.
(författare)
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Evolution of genes and genomes on the Drosophila phylogeny
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
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Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
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| 12. |
- Furusjö, Erik, 1972-, et al.
(författare)
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Alkali enhanced biomass gasification with in situ S capture and novel syngas cleaning. Part 1 : Gasifier performance
- 2018
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Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 157, s. 96-105
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Tidskriftsartikel (refereegranskat)abstract
- Previous research shows that alkali addition in entrained flow biomass gasification can increase char conversion and decrease tar and soot formation through catalysis. This paper investigates two other potential benefits of alkali addition: increased slag flowability and in situ sulfur capture. Thermodynamic equilibrium calculations show that addition of 2–8% alkali catalyst to biomass completely changes the chemical domain of the gasifier slag phase to an alkali carbonate melt with low viscosity. This can increase feedstock flexibility and improve the operability of an entrained flow biomass gasification process. The alkali carbonate melt also leads to up to 90% sulfur capture through the formation of alkali sulfides. The resulting reduced syngas sulfur content can potentially simplify gas cleaning required for catalytic biofuel production. Alkali catalyst recovery and recycling is a precondition for the economic feasibility of the proposed process and is effected through a wet quench. It is shown that the addition of Zn for sulfur precipitation in the alkali recovery loop enables the separation of S, Ca and Mg from the recycle. For high Si and Cl biomass feedstocks, an alternative separation technology for these elements may be required to avoid build-up.
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| 13. |
- Guimaraes, Drielle D., et al.
(författare)
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Dietary Nitrate Reduces Blood Pressure in Rats With Angiotensin II-Induced Hypertension via Mechanisms That Involve Reduction of Sympathetic Hyperactivity
- 2019
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Ingår i: Hypertension. - : Lippincott Williams & Wilkins. - 0194-911X .- 1524-4563. ; 73:4, s. 839-848
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Tidskriftsartikel (refereegranskat)abstract
- Several experimental and clinical studies have shown that dietary nitrate supplementation can increase nitric oxide bioavailability. In the oral cavity, commensal bacteria reduce nitrate to nitrite, which is subsequently absorbed into the circulation where reduction to nitric oxide by enzymatic systems occur. Although it is well-known that boosting the nitrate-nitrite-nitric oxide pathway can improve cardiovascular, renal, and metabolic functions and that sympathoexcitation contributes to the development of the same disorders, the potential effects of dietary nitrate on sympathetic activity remain to be elucidated. In this study, we hypothesized that treatment with inorganic nitrate could prevent the increase in sympathetic nerve activity in an experimental model of Ang II (angiotensin II)-induced hypertension. Multiple in vivo approaches were combined, that is, Wistar rats orally treated with the nitric oxide synthase inhibitor L-NAME (N(G)-nitro-L-arginine methyl ester, 0.5 g/L) and implanted with subcutaneous osmotic minipump for continuous delivery of Ang II (120 ng/kg per minute; 14 days). Simultaneously, rats were supplemented with sodium nitrate (10 mmol/L) or placebo (sodium chloride; 10 mmol/L) in the drinking water. Blood pressure, heart rate, and renal sympathetic nerve activity were recorded. In placebo-treated rats, Ang II+ L-NAME treatment-induced arterial hypertension, which was linked with reduced spontaneous baroreflex sensitivity and increased renal sympathetic nerve activity, as well as upregulation of AT 1 Rs (Ang II type-1 receptors) in the rostral ventrolateral medulla. Supplementation with nitrate normalized the expression of AT 1 Rs in rostral ventrolateral medulla and reduced sympathetic nerve activity, which was associated with attenuated development of hypertension. In conclusion, chronic dietary nitrate supplementation blunted the development of hypertension via mechanisms that involve reduction of sympathetic outflow.
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| 14. |
- Hudson, Lawrence N, et al.
(författare)
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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
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Tidskriftsartikel (refereegranskat)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
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| 15. |
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| 16. |
- Khatri, C, et al.
(författare)
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Outcomes after perioperative SARS-CoV-2 infection in patients with proximal femoral fractures: an international cohort study
- 2021
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Ingår i: BMJ open. - : BMJ. - 2044-6055. ; 11:11, s. e050830-
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Tidskriftsartikel (refereegranskat)abstract
- Studies have demonstrated high rates of mortality in people with proximal femoral fracture and SARS-CoV-2, but there is limited published data on the factors that influence mortality for clinicians to make informed treatment decisions. This study aims to report the 30-day mortality associated with perioperative infection of patients undergoing surgery for proximal femoral fractures and to examine the factors that influence mortality in a multivariate analysis.SettingProspective, international, multicentre, observational cohort study.ParticipantsPatients undergoing any operation for a proximal femoral fracture from 1 February to 30 April 2020 and with perioperative SARS-CoV-2 infection (either 7 days prior or 30-day postoperative).Primary outcome30-day mortality. Multivariate modelling was performed to identify factors associated with 30-day mortality.ResultsThis study reports included 1063 patients from 174 hospitals in 19 countries. Overall 30-day mortality was 29.4% (313/1063). In an adjusted model, 30-day mortality was associated with male gender (OR 2.29, 95% CI 1.68 to 3.13, p<0.001), age >80 years (OR 1.60, 95% CI 1.1 to 2.31, p=0.013), preoperative diagnosis of dementia (OR 1.57, 95% CI 1.15 to 2.16, p=0.005), kidney disease (OR 1.73, 95% CI 1.18 to 2.55, p=0.005) and congestive heart failure (OR 1.62, 95% CI 1.06 to 2.48, p=0.025). Mortality at 30 days was lower in patients with a preoperative diagnosis of SARS-CoV-2 (OR 0.6, 95% CI 0.6 (0.42 to 0.85), p=0.004). There was no difference in mortality in patients with an increase to delay in surgery (p=0.220) or type of anaesthetic given (p=0.787).ConclusionsPatients undergoing surgery for a proximal femoral fracture with a perioperative infection of SARS-CoV-2 have a high rate of mortality. This study would support the need for providing these patients with individualised medical and anaesthetic care, including medical optimisation before theatre. Careful preoperative counselling is needed for those with a proximal femoral fracture and SARS-CoV-2, especially those in the highest risk groups.Trial registration numberNCT04323644
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| 17. |
- Koyanagi, Ai, et al.
(författare)
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Chronic Physical Conditions, Multimorbidity, and Mild Cognitive Impairment in Low- and Middle-Income Countries
- 2018
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Ingår i: Journal of The American Geriatrics Society. - : Wiley-Blackwell. - 0002-8614 .- 1532-5415. ; 66:4, s. 721-727
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To assess the association between chronic physical conditions and multimorbidity and mild cognitive impairment (MCI) in low- and middle-income countries (LMICs).DESIGN: Nationally representative, cross-sectional, community-based study.SETTING: Six countries that participated in the World Health Organization Study on Global Ageing and Adult Health.PARTICIPANTS: Individuals aged 50 and older (N=32,715; mean age 62.1 ± 15.6; 51.7% female).MEASUREMENTS: The definition of MCI was based on the recommendations of the National Institute on Ageing and Alzheimer's Association. Ten chronic conditions were assessed (angina pectoris, arthritis, asthma, cataract, chronic lung disease, diabetes mellitus, edentulism, hearing problems, hypertension, stroke). Multivariable logistic regression analysis was conducted to assess the association between chronic physical conditions, multimorbidity (≥2 chronic conditions), and MCI.RESULTS: The prevalence of multimorbidity was 49.8% (95% confidence interval (CI)=48.1-51.5%) and of MCI was 15.3% (95% CI=14.4-16.3%). After adjustment for potential confounders, edentulism (odds ratio (OR)=1.24), arthritis (OR=1.24), chronic lung disease (OR=1.29), cataract (OR=1.33), stroke (OR=1.94), hearing problems (OR=2.27), and multimorbidity (OR=1.40) were significantly associated with MCI. There was a gradual increase in the likelihood of MCI (1 condition: OR=1.21, 95% CI=1.03-1.42; ≥4 conditions: OR=2.07, 95% CI=1.70-2.52).CONCLUSION: These results highlight the need to investigate the underlying mechanisms linking chronic conditions and MCI and whether prevention or treatment of chronic conditions or multimorbidity can reduce the onset of cognitive decline and subsequent dementia, especially in LMICs.
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| 18. |
- Li, Fangfang, et al.
(författare)
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Combination of CO2 electrochemical reduction and biomass gasification for producing methanol : A techno-economic assessment
- 2024
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Ingår i: Energy Conversion and Management. - : Elsevier Ltd. - 0196-8904 .- 1879-2227. ; 307
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Tidskriftsartikel (refereegranskat)abstract
- Combining CO2 electrochemical reduction (CO2R) and biomass gasification for producing methanol (CH3OH) is a promising option to increase the carbon efficiency, reduce total production cost (TPC), and realize the utilization of byproducts of CO2R system, but its viability has not been studied. In this work, systematic techno-economic assessments for the processes that combined CO2R to produce CO/syngas/CH3OH with biomass gasification were conducted and compared to stand-alone biomass gasification and CO2R processes, to identify the benefits and analyze the commercialization potential of different pathways under current and future conditions. The results demonstrated that the process that combined biomass gasification with CO2R to CO represents a viable pathway with a competitive TPC of 0.39 €/kg-CH3OH under the current condition. For all the combined cases, electricity usage for CO2R accounts for 36–76% of total operating cost, which plays a key role for TPC. Sensitivity analysis confirmed that the process that combined biomass gasification with CO2R to CO is sensitive to the price of electricity, while both CO2R performance and prices of stack and electricity are important for the processes that combined with CO2R to syngas/CH3OH.
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| 19. |
- Schwabl, M., et al.
(författare)
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Development of a biomass heating device for low energy and passive houses
- 2013
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Ingår i: Management of environmental quality. - 1477-7835 .- 1758-6119. ; 24:5, s. 652-666
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Decreasing energy demand due to improved building standards requires the development of new biomass combustion technologies to be able to provide individual biomass heating solutions. The purpose of this paper is, therefore, the development of a pellet water heating stove with minimal emission at high thermal efficiency. Design/methodology/approach: The single components of a 10 kW water heating pellet stove are analysed and partly redesigned considering the latest scientific findings and experimental know-how in combustion engineering. The outcome of this development is a 12 kW prototype which is subsequently down-scaled to a 6 kW prototype. Finally, the results of the development are evaluated by testing of an accredited institute. Findings: Based on an existing pellet water heating stove, the total excess air ratio was reduced, a strict air staging was implemented and the fuel supply was homogenized. All three measures improved the operating performance regarding emissions and thermal efficiency. The evaluation of the development process showed that the CO emissions are reduced by over 90 per cent during full load and by 30-60 per cent during minimum load conditions. Emissions of particulate matter are reduced by 70 per cent and the thermal efficiency increased to 95 per cent. Originality/value: The result represents a new state of technology in this sector for minimal emissions and maximal thermal efficiency, which surpasses the directives of the Eco label "UZ37" in Austria and "Blauer Engel" in Germany, which are amongst the most stringent performance requirements in the European Union. Hence this design possesses a high potential as heating solution for low and passive energy houses.
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| 20. |
- Wilkinson, John L., et al.
(författare)
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Pharmaceutical pollution of the world's rivers
- 2022
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 119:8
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Tidskriftsartikel (refereegranskat)abstract
- Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world's rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.
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| 21. |
- Xie, Y., et al.
(författare)
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A critical review on production, modification and utilization of biochar
- 2022
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier B.V.. - 0165-2370 .- 1873-250X. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- There has been an increased interest in the production of sustainable biochar in the past years, as biochar shows versatile physicochemical properties and, can have a wide applicability in diverse fields. Comprehensive studies have been made to characterize biochar produced from various biomass materials, using different production technologies and under different process conditions. However, research is still lacking in correlating biochar properties needed for certain applications with (i) feedstock, (ii) biochar production processes and conditions and (iii) biochar upgrading and modification strategies. To produce biochar with desired properties, there is a great need to establish and clarify such correlations, which can guide the selection of feedstock, tuning and optimization of the production process and more efficient utilization of biochar. On the other hand, further elucidation of these correlations is also important for biochar-stakeholder and end-users for predicting physiochemical properties of biochar from certain feedstock and production conditions, assessing potential effects of biochar utilization and clearly address needs towards biochar critical properties. This review summarizes a wide range of literature on the impact of feedstocks and production processes and reactions conditions on the biochar properties and the most important biochar properties required for the different potential applications. Based on collected data, recommendations are provided for mapping out biochar production for different biochar applications. Knowledge gaps and perspectives for future research have also been identified regarding the characterization and production of biochar.
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| 22. |
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| 23. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 24. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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