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- Kudahettige-Nilsson, Rasika L., et al.
(författare)
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Biobutanol Production by Clostridium acetobutylicum Using Xylose Recovered from Birch Kraft Black Liquor
- 2015
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 176, s. 71-79
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Tidskriftsartikel (refereegranskat)abstract
- Acetone-Butanol-Ethanol (ABE) fermentation was studied using acid-hydrolyzed xylan recovered from hardwood Kraft black liquor by CO2 acidification as the only carbon source. Detoxification of hydrolyzate using activated carbon was conducted to evaluate the impact of inhibitor removal and fermentation. Xylose hydrolysis yields as high as 18.4% were demonstrated at the highest severity hydrolysis condition. Detoxification using active carbon was effective for removal of both phenolics (76-81%) and HMF (38-52%). Batch fermentation of the hydrolyzate and semi-defined P2 media resulted in a total solvent yield of 0.12-0.13 g/g and 0.34 g/g, corresponding to a butanol concentration of 1.8-2.1 g/L and 7.3 g/L respectively. This work is the first study of a process for the production of a biologically-derived biofuel from hemicelluloses solubilized during Kraft pulping and demonstrates the feasibility of utilizing xylan recovered directly from industrial Kraft pulping liquors as a feedstock for biological production of biofuels such as butanol.
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| 2. |
- Bonturi, Nemailla, et al.
(författare)
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Single Cell Oil Producing Yeasts Lipomyces starkeyi and Rhodosporidium toruloides : Selection of Extraction Strategies and Biodiesel Property Prediction
- 2015
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 8:6, s. 5040-5052
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Tidskriftsartikel (refereegranskat)abstract
- Single cell oils (SCOs) are considered potential raw material for the production of biodiesel. Rhodosporidium sp. and Lipomyces sp. are good candidates for SCO production. Lipid extractability differs according to yeast species and literature on the most suitable method for each oleaginous yeast species is scarce. This work aimed to investigate the efficiency of the most cited strategies for extracting lipids from intact and pretreated cells of Rhodosporidium toruloides and Lipomyces starkeyi. Lipid extractions were conducted using hexane or combinations of chloroform and methanol. The Folch method resulted in the highest lipid yields for both yeasts (42% for R. toruloides and 48% for L. starkeyi). Also, this method eliminates the cell pretreatment step. The Bligh and Dyer method underestimated the lipid content in the tested strains (25% for R. toruloides and 34% for L. starkeyi). Lipid extractability increased after acid pretreatment for the Pedersen, hexane, and Bligh and Dyer methods. For R. toruloides unexpected fatty acid methyl esters (FAME) composition were found for some lipid extraction strategies tested. Therefore, this work provides useful information for analytical and process development aiming at biodiesel production from the SCO of these two yeast species.
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| 3. |
- Keshavarzi, Neda, et al.
(författare)
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Nanocellulose-Zeolite Composite Films for Odor Elimination
- 2015
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 7:26, s. 14254-14262
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Tidskriftsartikel (refereegranskat)abstract
- Free standing and strong odor-removing composite films of cellulose nanofibrils (CNF) with a high content of nanoporous zeolite adsorbents have been colloidally processed. Thermogravimetric desorption analysis (TGA) and infrared spectroscopy combined with computational simulations showed that commercially available silicalite-1 and ZSM-5 have a high affinity and uptake of volatile odors like ethanethiol and propanethiol, also in the presence of water. The simulations showed that propanethiol has a higher affinity, up to 16%, to the two zeolites compared with ethanethiol. Highly flexible and strong free-standing zeolite CNF films with an adsorbent loading of 89 w/w% have been produced by Ca-induced gelation and vacuum filtration. The CNF-network controls the strength of the composite films and 100 mu m thick zeolite CNF films with a CNF content of less than 10 vol % displayed a tensile strength approaching 10 MPa. Headspace solid phase microextraction (SPME) coupled to gas chromatography mass spectroscopy (GC/MS) analysis showed that the CNF zeolite films can eliminate the volatile thiol-based odors to concentrations below the detection ability of the human olfactory system. Odor removing zeolite-cellulose nanofibril films could enable improved transport and storage of fruits and vegetables rich in odors, for example, onion and the tasty but foul-smelling South-East Asian Durian fruit.
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| 6. |
- Lögdberg, Ulrika, et al.
(författare)
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"Thinking about the future, what's gonna happen?" : How young people in Sweden who neither work nor study perceive life experiences in relation to health and well-being
- 2018
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Ingår i: International Journal of Qualitative Studies on Health and Well-being. - : Taylor & Francis. - 1748-2623 .- 1748-2631. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The aim of this study was to explore how young people in Sweden who neither work nor study perceive life experiences in relation to health and well-being.Methods: A task-based interview technique was used and data was analysed with qualitative content analysis. Interviews were conducted with 16 participants aged 16-20 who were unemployed and not eligible for upper secondary school, or who had dropped out of school.Results: Three themes emerged from the analysis illustrating how the young people perceive their life experiences in relation to health and well-being: Struggling with hardships in the absence of caring connections, Feeling good when closely connected to others, and Being forced to question what has been taken for granted. Each theme consists of 2-3 subthemes.Conclusion: Based on the young people's narrated experiences health can be understood as: something that is created in relation to others and in relation to the social and cultural context; as something dynamic and changeable; as the ability to adapt and respond to challenges; and finally as something existing on a collective as well as an individual level. Implications for school, social services and health promotion initiatives are discussed, with an emphasis on working with young people.
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| 7. |
- Lögdberg, Ulrika, et al.
(författare)
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Using photovoice to promote young migrants health : benefits and challenges with the method
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: Young migrants are a group that are seldom asked to share their experiences of health. More research focusing on an inside perspective on young migrants health is needed. Through photovoice, young people are given the opportunity to document and discuss their lives by using photography.Purpose of study: Illuminating experiences from collaborating with young migrants to promote health using photovoice, focusing on benefits and challenges with the method. Methods/Theory: The study was based on a social perspective on health. Photovoice was the chosen method inviting 28 young migrants in a municipality in northern Sweden aged 16-20 from 5 different countries to take pictures and discussing these with focus on experiences and conditions for health and how health can be promoted. The four step process: 1) Introduction, 2) Photographing session, 3) Workshops, and 4) Final presentation. Findings: Using photovoice with young migrants enabled insights into several aspects of the participants’ everyday life inside and outside the school context. The participants could identify health promotion factors but also health challenges in their everyday life. More important, it enabled conversations based on the participants' pictures of their lives rather than questions posed by the researcher. The study also revealed ethical challenges addressing power imbalance and how to reach social change, which is further discussed. Conclusion: We recommend using photovoice with young migrants as it proved to be a rich tool to promote critical thinking and discussions allowing self-reflection. However, more research is needed to discuss how to reach social change, the last step of the method.
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