| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Mandenius, C. F., et al.
(författare)
-
Predicting fermentability of wood hydrolyzates with responses from electronic noses
- 1999
-
Ingår i: Biotechnology progress (Print). - New York, NY, United States : AIChE. - 8756-7938 .- 1520-6033. ; 15:4, s. 617-621
-
Tidskriftsartikel (refereegranskat)abstract
- The fermentability of lignocellulose hydrolyzates have been predicted from the responses of a combination of chemical gas sensors. The hydrolyzates were prepared by dilute-acid hydrolysis of wood from pine, aspen, birch, and spruce. The volatile emission from the hydrolyzates before fermentation was measured, and the sensor array response pattern was compared with the observed fermentability of the hydrolyzates, i.e. with the final ethanol concentration after fermentation and the maximum specific ethanol production rate. Two concentration parameters in the hydrolyzates, furfural and the sum of furfural and 5-(hydroxymethyl)furfural (HMF), were also predicted from the responses. The sensors used were metal oxide semiconductor field effect transistors (MOSFET), tin oxide semiconductor devices, and conductive polymer sensors configured in two sensor arrays. The sensor array response pattern was analyzed by principal component analysis and artificial neural networks. Predictions from artificial neural networks deviated from measured values with less than 15%.The fermentability of lignocellulose hydrolyzates have been predicted from the responses of a combination of chemical gas sensors. The hydrolyzates were prepared by dilute-acid hydrolysis of wood from pine, aspen, birch, and spruce. The volatile emission from the hydrolyzates before fermentation was measured, and the sensor array response pattern was compared with the observed fermentability of the hydrolyzates, i.e. with the final ethanol concentration after fermentation and the maximum specific ethanol production rate. Two concentration parameters in the hydrolyzates, furfural and the sum of furfural and 5-(hydroxymethyl)furfural (HMF), were also predicted from the responses. The sensors used were metal oxide semiconductor field effect transistors (MOSFET), tin oxide semiconductor devices, and conductive polymer sensors configured in two sensor arrays. The sensor array response pattern was analyzed by principal component analysis and artificial neural networks. Predictions from artificial neural networks deviated from measured values with less than 15%.
|
|
| 7. |
- Abdelaziz, Omar Y., et al.
(författare)
-
Biological valorization of low molecular weight lignin
- 2016
-
Ingår i: Biotechnology Advances. - : Elsevier BV. - 0734-9750. ; 34:8, s. 1318-1346
-
Forskningsöversikt (refereegranskat)abstract
- Lignin is a major component of lignocellulosic biomass and as such, it is processed in enormous amounts in the pulp and paper industry worldwide. In such industry it mainly serves the purpose of a fuel to provide process steam and electricity, and to a minor extent to provide low grade heat for external purposes. Also from other biorefinery concepts, including 2nd generation ethanol, increasing amounts of lignin will be generated. Other uses for lignin – apart from fuel production – are of increasing interest not least in these new biorefinery concepts. These new uses can broadly be divided into application of the polymer as such, native or modified, or the use of lignin as a feedstock for the production of chemicals. The present review focuses on the latter and in particular the advances in the biological routes for chemicals production from lignin. Such a biological route will likely involve an initial depolymerization, which is followed by biological conversion of the obtained smaller lignin fragments. The conversion can be either a short catalytic conversion into desired chemicals, or a longer metabolic conversion. In this review, we give a brief summary of sources of lignin, methods of depolymerization, biological pathways for conversion of the lignin monomers and the analytical tools necessary for characterizing and evaluating key lignin attributes.
|
|
| 8. |
- Abdelaziz, Omar Y., et al.
(författare)
-
Oxidative Depolymerization of Kraft Lignin for Microbial Conversion
- 2019
-
Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 7:13, s. 11640-11652
-
Tidskriftsartikel (refereegranskat)abstract
- The valorization of lignin is being increasingly recognized as crucial to improve the economic viability of integrated biorefineries. Because of its inherent heterogeneity and recalcitrance, lignin has been treated as a waste product in the pulp and paper industry, but new technologies are now being explored to transform lignin into a sustainable resource and enhance its value chain. In the present study, alkaline oxidative depolymerization was investigated as a potential form of pretreatment to enable further biological conversion of LignoBoost kraft lignin (LB). LB lignin oxidation reactions were studied at various temperatures (120-200 °C) and O2 partial pressures (3-15 bar) to identify the optimal conditions for obtaining a biocompatible, oxidatively depolymerized lignin (ODLB) stream. The low molecular weight compounds resulting from this treatment consisted mainly of aromatic monomers and carboxylic acids. The highest yield of aromatic monomers, 3 wt %, was obtained at 160 °C and 3 bar O2. The yield of carboxylic acids increased with both increasing temperature and O2 pressure, exceeding 13% under the harshest conditions investigated. The growth of four aromatic-catabolizing bacterial strains was examined on reaction product mixtures, all of which showed growth on agar plates utilizing ODLB as the sole source of carbon and energy. Rhodococcus opacus and Sphingobium sp. SYK-6 were found to consume most of the aromatic monomers present in the ODLB (e.g., vanillin, vanillate, acetovanillone, and guaiacol). The findings of this study indicate that pretreatment by oxidative depolymerization has potential in the biological valorization of technical lignin streams, for the production of valuable chemicals and materials.
|
|
| 9. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
-
A Multipath TCP Proxy
- 2015
-
Konferensbidrag (refereegranskat)abstract
- Multipath TCP (MPTCP) is an extension to traditionalTCP that enables a number of performance advantages,which were not offered before. While the protocol specificationis close to being finalized, there still remain some concernsregarding deployability and security. This paper describes theon going work to develop a solution that will facilitate thedeployment of MPTCP. The solution will not only allow non-MPTCP capable end-hosts to benefit from MPTCP performancegains, but also help ease the network security concerns that manymiddleboxes face due to the possibility of data stream beingfragmented across multiple subflows.
|
|
| 10. |
- Afzal, Zeeshan, 1991-, et al.
(författare)
-
Towards Multipath TCP Aware Security Technologies
- 2016
-
Ingår i: 2016 8th IFIP International Conference onNew Technologies, Mobility and Security (NTMS). - New York : IEEE. - 9781509029143 ; , s. 1-8
-
Konferensbidrag (refereegranskat)abstract
- Multipath TCP (MPTCP) is a proposed extension to TCP that enables a number of performance advantages that have not been offered before. While the protocol specification is close to being finalized, there still remain some unaddressed challenges regarding the deployment and security implications of the protocol. This work attempts to tackle some of these concerns by proposing and implementing MPTCP aware security services and deploying them inside a proof of concept MPTCP proxy. The aim is to enable hosts, even those without native MPTCP support, to securely benefit from the MPTCP performance advantages. Our evaluations show that the security services that are implemented enable proper intrusion detection and prevention to thwart potential attacks as well as threshold rules to prevent denial of service (DoS) attacks.
|
|
| 11. |
- Agvall, B., et al.
(författare)
-
Characteristics, management and outcomes in patients with CKD in a healthcare region in Sweden: a population-based, observational study
- 2023
-
Ingår i: Bmj Open. - London : BMJ Publishing Group Ltd. - 2044-6055. ; 13:7
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectivesTo describe chronic kidney disease (CKD) regarding treatment rates, comorbidities, usage of CKD International Classification of Diseases (ICD) diagnosis, mortality, hospitalisation, evaluate healthcare utilisation and screening for CKD in relation to new nationwide CKD guidelines. DesignPopulation-based observational study. SettingHealthcare registry data of patients in Southwest Sweden. ParticipantsA total cohort of 65 959 individuals aged >18 years of which 20 488 met the criteria for CKD (cohort 1) and 45 470 at risk of CKD (cohort 2). Primary and secondary outcome measuresData were analysed with regards to prevalence, screening rates of blood pressure, glucose, estimated glomerular filtration rate (eGFR), Urinary-albumin-creatinine ratio (UACR) and usage of ICD-codes for CKD. Mortality and hospitalisation were analysed with logistic regression models. ResultsOf the CKD cohort, 18% had CKD ICD-diagnosis and were followed annually for blood pressure (79%), glucose testing (76%), eGFR (65%), UACR (24%). UACR follow-up was two times as common in hypertensive and cardiovascular versus diabetes patients with CKD with a similar pattern in those at risk of CKD. Statin and renin-angiotensin-aldosterone inhibitor appeared in 34% and 43%, respectively. Mortality OR at CKD stage 5 was 1.23 (CI 0.68 to 0.87), diabetes 1.20 (CI 1.04 to 1.38), hypertension 1.63 (CI 1.42 to 1.88), atherosclerotic cardiovascular disease (ASCVD) 1.84 (CI 1.62 to 2.09) associated with highest mortality risk. Hospitalisation OR in CKD stage 5 was 1.96 (CI 1.40 to 2.76), diabetes 1.15 (CI 1.06 to 1.25), hypertension 1.23 (CI 1.13 to 1.33) and ASCVD 1.52 (CI 1.41 to 1.64). ConclusionsThe gap between patients with CKD by definition versus those diagnosed as such was large. Compared with recommendations patients with CKD have suboptimal follow-up and treatment with renin-angiotensin-aldosterone system inhibitor and statins. Hypertension, diabetes and ASCVD were associated with increased mortality and hospitalisation. Improved screening and diagnosis of CKD, identification and management of risk factors and kidney protective treatment could affect clinical and economic outcomes.
|
|
| 12. |
- Ahlgren, Hans, et al.
(författare)
-
Multiple prehistoric introductions of the mountain hare (Lepus timidus) on a remote island, as revealed by ancient DNA
- 2016
-
Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 43:9, s. 1786-1796
-
Tidskriftsartikel (refereegranskat)abstract
- Aim: The majority of the non-volant mammals now present on the island of Gotland, Sweden, have been introduced in modern times. One exception is the mountain hare (Lepus timidus), which was present on the island more than 9000 years ago. This paper investigates the origins of the Gotland hares and temporal changes in their genetic structure, and considers how they may have reached the island.Location: The island of Gotland, Sweden (57°30′ N, 18°20′ E).Methods: Two fragments of the mitochondrial D-loop 130 + 164 base pairs in length from skeletal remains from 40 ancient mountain hares from Gotland, 38 from the Swedish mainland and five from Lithuania were analysed and compared with 90 modern L. timidus haplotypes from different locations in Eurasia and five haplotypes of the Don-hare (Lepus tanaiticus) morphotype.Results: The Mesolithic hares from Gotland (7304 bc–5989 bc) cluster with modern hares from Russia, Scotland, the Alps and Fennoscandia whereas the Gotland hares from the Neolithic and onwards (2848 bc–1641 ad) cluster with Neolithic hares from the Swedish mainland and modern hares from Fennoscandia. The Neolithic haplotypes from Lithuania and the Don-hare haplotypes were dispersed within the network. The level of differentiation (FST) between the Mesolithic and Neolithic hares on Gotland was twice as great as that observed on the mainland.Main conclusions: The ancient hares on Gotland fall into two haplogroups separated in time, indicating that the mountain hare became extinct at one point, with subsequent re-colonization events. In view of the isolated location of Gotland, it is probable that the hares were brought there by human means of transport.
|
|
| 13. |
- Ahlgren, Hans, 1984-
(författare)
-
Prehistoric human impact on wild mammalian populations in Scandinavia
- 2021
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims to study the interactions of pre-agricultural societies in Scandinavia with wild mammals, for example in terms of hunting and translocation. More specifically, the aim is to investigate the possibility of identifying examples of overexploitation, targeted hunting or translocation of wild mammals in prehistoric Scandinavia, and to discuss the implications this could have had for both the wild animals and the humans. The thesis also studies translocation to evaluate the feasibility of using it as a proxy for prehistoric human mobility, and to understand the motivation for this action. Although the focus is on the animals in this thesis, the ultimate purpose is to study humans and their interactions with animals in prehistory. The thesis applies genetic analyses to zooarchaeological material of various mammalian species from different Scandinavian sites, in order to study whether the genetic structures have changed in these species over time, and to assess whether these changes were induced by different human actions. The species studied in this thesis were selected on the basis of the importance they are considered to have had for prehistoric people.The dissertation comprises five studies. The first study investigates the occurrence of mountain hares on the island of Gotland, and discusses how they got there and where they came from. The second study explores the temporal genetic structure of the grey seal in the Baltic Sea, and discusses whether humans and/or climate were the drivers for the sudden disappearance of grey seals from the island of Stora Karlsö. The third study concerns a shift where moose apparently became less important as prey in northern Sweden at the end of the Neolithic period, and discusses whether humans targeted female moose in hunting. The fourth study analyses and discusses the history of the harp seal in the Baltic Sea. The fifth study is a methodological paper which involves identifying seals according to sex, using the dog genome.The overall result of the different case studies shows that there were major population fluctuations over time in all the species studied, and that in some cases, humans are likely to have contributed to this, e.g. through overhunting and translocation. The study also shows that the population fluctuations often occurred in connection with certain climatic events, though it was not possible to separate climatic effects from human impact in terms of the cause.
|
|
| 14. |
- Ahlgren, Hans, 1984-, et al.
(författare)
-
The Baltic grey seal : A 9000-year history of presence and absence
- 2022
-
Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 32:6, s. 569-577
-
Tidskriftsartikel (refereegranskat)abstract
- The grey seal (Halichoerus grypus) has been part of the Baltic Sea fauna for more than 9000 years and has ever since been subjected to extensive human hunting, particularly during the early phases of its presence in the Baltic Sea, but also in the early 20th century. In order to study their temporal genetic structure and to investigate whether there has been a genetically continuous grey seal population in the Baltic, we generated mitochondrial control region data from skeletal remains from ancient grey seals from the archaeological sites Stora Förvar (Sweden) and Neustadt (Germany) and compared these with modern grey seal data. We found that the majority of the Mesolithic grey seals represent haplotypes that is not found in contemporary grey seals, indicating that the Baltic Sea population went extinct, likely due to human overexploitation and environmental change. We hypothesize that grey seals recolonised the Baltic Sea from the North Sea. during the Bronze Age or Iron Age, and that the contemporary Baltic grey seal population is direct descendants of this recolonisation. Our study highlights the power of biomolecular archaeology to understand the factors that shape contemporary marine diversity.
|
|
| 15. |
|
|
| 16. |
- Ahlstrand, Erik, 1974-, et al.
(författare)
-
Visual scoring of chest CT at hospital admission predicts hospitalization time and intensive care admission in Covid-19
- 2021
-
Ingår i: Infectious Diseases. - : Taylor & Francis. - 2374-4235 .- 2374-4243. ; 53:8, s. 622-632
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Chest CT is prognostic in Covid-19 but there is a lack of consensus on how to report the CT findings. A chest CT scoring system, ÖCoS, was implemented in clinical routine on 1 April 2020, in Örebro Region, Sweden. The ÖCoS-severity score measures the extent of lung involvement. The objective of the study was to evaluate the ÖCoS scores as predictors of the clinical course of Covid-19.METHODS: Population based study including data from all hospitalized patients with Covid-19 in Örebro Region during March to July 2020. We evaluated the correlations between CT scores at the time of admission to hospital and intensive care in relation to hospital and intensive care length of stay (LoS), intensive care admission and death. C-reactive protein and lymphocyte count were included as covariates in multivariate regression analyses.RESULTS: In 381 included patients, the ÖCoS-severity score at admission closely correlated to hospital length of stay, and intensive care admission or death. At admission to intensive care, the ÖCoS-severity score correlated with intensive care length of stay. The ÖCoS-severity score was superior to basic inflammatory biomarkers in predicting clinical outcomes.CONCLUSION: Chest CT visual scoring at admission to hospital predicted the clinical course of Covid-19 pneumonia.
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
- Ait-Ali, Abderrahman, 1991-, et al.
(författare)
-
Minimal utilization rate for railway maintenance windows : a cost-benefit approach
- 2022
-
Ingår i: European Journal of Transport and Infrastructure Research. - : TU Delft. - 1567-7133 .- 1567-7141. ; 22:2, s. 108-131
-
Tidskriftsartikel (refereegranskat)abstract
- Methods for economic assessment are often used in the rail sector to evaluate large infrastructure investments such as new high-speed lines. With larger networks and ageing infrastructure, these methods can also be used for planning maintenance. In this paper, we focus on the newly introduced concept of maintenance windows in Sweden. These are pre-allocated slots in the train timetable dedicated to performing, among others, periodic/frequent maintenance activities. To justify the pre-allocation of such windows, this study presents a method to find minimal utilization rates depending on window designs and traffic situations. Using a cost-benefit approach, the windows are assessed using a total social cost including work costs, loss in traffic production and reliability gains in future traffic. Based on a case study from the Southern main line in Sweden, we study the minimal utilization rate in different test scenarios, i.e., night or day shifts, asset degradation functions and designs of maintenance windows. The results show that lower utilization rates (4-42%) can be accepted during low-volume traffic or for partial closures, while higher utilization rates (47-83%) are required for full closures during high-volume traffic. Whether the rates are measured as the share of used window time or the share of utilized windows is less important, especially when higher utilization is required. Sensitivity analyses of asset knowledge indicate that parameters such as asset degradation function and minimum asset quality (and to a lesser extent traffic volume, discount rate and failure likelihood) can have a substantial effect on the minimum required utilization rates.
|
|
| 31. |
- Ait Ali, Abderrahman, et al.
(författare)
-
Minimal utilization rate for railway maintenance windows: a cost-benefit approach
- 2022
-
Ingår i: European Journal of Transport and Infrastructure Research. - : EDITORIAL BOARD EJTIR. - 1567-7133 .- 1567-7141. ; 22:2, s. 108-131
-
Tidskriftsartikel (refereegranskat)abstract
- Methods for economic assessment are often used in the rail sector to evaluate large infrastructure investments such as new high-speed lines. With larger networks and ageing infrastructure, these methods can also be used for planning maintenance. In this paper, we focus on the newly introduced concept of maintenance windows in Sweden. These are pre-allocated slots in the train timetable dedicated to performing, among others, periodic/frequent maintenance activities. To justify the pre-allocation of such windows, this study presents a method to find minimal utilization rates depending on window designs and traffic situations. Using a cost-benefit approach, the windows are assessed using a total social cost including work costs, loss in traffic production and reliability gains in future traffic. Based on a case study from the Southern main line in Sweden, we study the minimal utilization rate in different test scenarios, i.e., night or day shifts, asset degradation functions and designs of maintenance windows. The results show that lower utilization rates (4-42%) can be accepted during low-volume traffic or for partial closures, while higher utilization rates (47-83%) are required for full closures during high-volume traffic. Whether the rates are measured as the share of used window time or the share of utilized windows is less important, especially when higher utilization is required. Sensitivity analyses of asset knowledge indicate that parameters such as asset degradation function and minimum asset quality (and to a lesser extent traffic volume, discount rate and failure likelihood) can have a substantial effect on the minimum required utilization rates.
|
|
| 32. |
- Ait-Ali, Abderrahman, 1991-, et al.
(författare)
-
Minimal utilization rates for railway maintenance windows : a cost-benefit approach
- 2021
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Methods for economic assessment, e.g., cost-benefit analysis, are often used in the rail sector to evaluate large infrastructure investments such as building new high-speed railway lines. With larger railway networks and aging infrastructure, these methods can also be used for maintenance planning decisions. In this paper, we focus on basic maintenance and the newly introduced concept of maintenance windows in Sweden. These are pre-allocated slots in the annual train timetable dedicated to performing, among others, periodic/frequent maintenance activities such as inspections, maintenance and repairs. To justify the pre-allocation of such windows, this study presents a method to find minimal utilization rates depending on window designs and traffic situations. Using a cost-benefit approach, the maintenance windows are assessed using a total social cost including maintenance work costs, loss in traffic production and reliability gains in future traffic. Based on a case study from the Southern main line in Sweden, we study the minimal utilization rate in different test scenarios, i.e., night or day shifts, asset degradation functions and designs of maintenance windows. The results show that lower utilization rates (5-50%) can be accepted during low-volume traffic or for partial closures, while higher utilization rates (50-90%) are required for full closures during high-volume traffic. Whether the rates are measured as share of used window time or share of utilized windows is less important, especially when higher utilization is required.
|
|
| 33. |
|
|
| 34. |
- Alam, Anzar, et al.
(författare)
-
Online surface characterization of paper and paperboards in a wide-range of the spatial wavelength spectrum
- 2012
-
Ingår i: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 258:20, s. 7928-7935
-
Tidskriftsartikel (refereegranskat)abstract
- In the paper industry, surface topography is the essence of both paper and paperboard, and accurate topographical measurements are equally essential in order to achieve a uniform smooth surface. The traditional laboratory methods measure only a few samples from the entire tambour and there are other obvious limitations to this approach. Online measurements may be of significant value to improve the surface quality throughout the production. Roughness is one of the topography components and the majority of techniques measure paper by means of a single predictor of average roughness, R a which is inadequate in providing a comprehensive characterization of the surface. Measurements, in a wide range ofwavelengths, can characterize topography components such as roughness, waviness, cockling, etc. Online measurements were taken for various grades of 8 paper reels, containing the wireside and topsides for newspaper, and uncoated and coated sides of paperboards. Their surfacecharacterization, in the spatial wavelength spectrum, from 0.1 to 10 mm was obtained. This article presents the online characterizationresults which have efficiently distinguished the surfaces of same family materials including the edge and the middle position reels of fine coatedpaperboard. Online measurements were taken, at Iggesund Paperboard Pilot Coater in Sweden, by using a recently developed OnlineTopography (OnTop) device which is based on the principle of light triangulation. © 2012 Elsevier B.V. All rights reserved.
|
|
| 35. |
- Alam, Anzar, et al.
(författare)
-
Online surface roughness characterization of paper and paperboard using a line of light triangulation technique
- 2012
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 27:3, s. 662-670
-
Tidskriftsartikel (refereegranskat)abstract
- Within both the paper and paperboard industries, real time monitoring and measurement of surface roughness of a paper moving at high velocities is an important and challenging area of research. The uniform surface, for an entire production, can be effectively achieved by monitoring and controlling the paper surface roughness, in real time during the manufacturing steps. Presently the majority of paper industries rely on traditional laboratory profilometers. The obvious limitations of lab profilometers are that these are slow, do not measure the quality of entire reels but rather deal with only a few small pieces of samples taken from the end of the reels and it is difficult to make any possible correction in the productionlines without knowing the online roughness data. To eradicate the disadvantages associated with conventional measurements, an online prototype instrument has been developed that measures the surface roughness during the manufacturing steps, and is based on a line of lighttriangulation technique. The prototype technique will be of assistance in ensuring tight process control in order to maintain both a better and auniform quality throughout the entire production. It measures the whole reel, meter by meter, in traditional units of roughness and is also capable of characterizing the topography in a wide range of wavelength spectra. The article presents the online analyses results obtained from the developed prototype. The real time measurements, in a paperboard pilot mill, have successfully characterized and distinguished 16 different grades of newspaper and paperboard reels including reels which have the same family of quality grades and materials.
|
|
| 36. |
- Alam, Mohammad Anzar, et al.
(författare)
-
Investigation of the surface topographical differences between the Cross Direction and the Machine Direction for newspaper and paperboard
- 2011
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 26:4, s. 468-475
-
Tidskriftsartikel (refereegranskat)abstract
- Paper and paperboard surface quality is constantly being improved by the industry. This improvement work deals with the essential fact that the surface topography must be measured, both in relation to offline and online measurements for the manufactured products. Most measurements relating to surface topography (especially online) are performed either in the machine direction (MD) or in the cross direction (CD). It has been the opinion of SCA Ortviken AB and Iggesund Paperboard AB that the surface topography amplitudes are almost always higher in the CD than in the MD, for their products which consist of newspaper and paperboard. This article aims to investigate the rela-tionship between the CD and the MD surface topography amplitudes for a wide range of spatial wavelength for both newspaper and paperboard. The tests and investiga-tions have been conducted using an FRT Microprof profilometer within the range 20 μm up to 8 mm, and the results confirm that the surface topography amplitudes are higher in the CD for most of the shorter spatial wavelength within this range. The results also show significant differences between measurements for different paper qualities, suggesting a requirement to investigate the relationship between the CD and the MD topography for all paper and paperboard qualities of interest for a paper or paperboard mill, before a decision is made in relation to a measurement method.
|
|
| 37. |
|
|
| 38. |
- Albers, E, et al.
(författare)
-
Continuous estimation of product concentration with calorimetry and gas analysis during anaerobic fermentations of Saccharomyces cerevisiae
- 2002
-
Ingår i: Thermochimica Acta. - 0040-6031. ; 394:1-2, s. 185-190
-
Tidskriftsartikel (refereegranskat)abstract
- Product concentrations may be estimated from gas analysis or calorimetric measurements. These techniques of analysis are fast, simple, and provide a continuous output. To check the accuracy of these estimations, the anaerobic ethanol formation of an industrial strain of the yeast Saccharomyces cerevisiae was selected as a test system. Cultivations were carried out as batch cultures with different nitrogen sources (ammonium, glutamate and a mixture of amino acids) and 20 g/l of glucose as the carbon and energy source. The results showed that there was a good agreement between measured and calculated ethanol values. However, especially when using heat data the results are very sensitive to small changes in the stoichiometry of the catabolic reaction, i.e. ethanol is not the only product but there are also minor amounts of glycerol and acetate. The problems generated by these products when using heat data to calculate ethanol concentrations are discussed in detail. (C) 2002 Elsevier Science B.V. All rights reserved.
|
|
| 39. |
|
|
| 40. |
|
|
| 41. |
|
|
| 42. |
|
|
| 43. |
- Albin, Maria, et al.
(författare)
-
0253 Hairdressers are occupationally exposed to ortho- and meta- toluidine
- 2014
-
Ingår i: Occupational and Environmental Medicine. - : BMJ. - 1470-7926 .- 1351-0711. ; 71 Suppl 1, s. 32-33
-
Konferensbidrag (refereegranskat)abstract
- Hairdressing work is classified as carcinogenic based on excess risk for bladder cancer. We aimed at evaluating if current hairdressers are exposed to established/suspected bladder carcinogens (aromatic amines) and indicate possible sources of exposure.
|
|
| 44. |
- Albåge, Anders, et al.
(författare)
-
The Berglin apical stitch : a simple technique to straighten things out in atrial fibrillation surgery
- 2014
-
Ingår i: Interactive Cardiovascular and Thoracic Surgery. - : Oxford University Press (OUP). - 1569-9293 .- 1569-9285. ; 19:4, s. 685-686
-
Tidskriftsartikel (refereegranskat)abstract
- In the Cox-Maze IV procedure, or in endocardial left atrial ablation, correct positioning of the surgical ablation probe within the left atrium might be difficult due to bulging or folds in the posterior left atrial wall. The Berglin apical stitch is a simple trick of the trade to create a smooth surface in the posterior left atrium that facilitates performing a safe transmural lesion and, consequently, may increase antiarrhythmic efficiency.
|
|
| 45. |
- Alkasrawi, Malek, et al.
(författare)
-
Influence of strain and cultivation procedure on the performance of simultaneous saccharification and fermentation of steam pretreated spruce
- 2006
-
Ingår i: Enzyme and Microbial Technology. - : Elsevier BV. - 0141-0229. ; 38:1-2, s. 279-286
-
Tidskriftsartikel (refereegranskat)abstract
- Yeast to be used in simultaneous saccharification and fermentation (SSF) of lignocelluloses materials has to be prepared in a separate cultivation step. The effects of the cultivation procedure on the performance of SSF of steam pretreated softwood were studied in the current work. The yeast used in the SSF was either directly commercially available Baker's yeast (as packaged yeast) or the same strain of yeast produced from the hydrolysate obtained in the pretreatment of the softwood material. A second strain of Saccharomyces cerevisiae TMB3000. isolated from spent sulphite liquor, was also compared with the commercial Baker's yeast. The strains were tested in SSF at substrate loads of 3, 5 and 8% dry weight of water insoluble material. Final ethanol yields were above 85% of the theoretical (based on the available hexoses) in all cases, except for the package yeast for the 8% substrate load, in which case the final yield was less than 65%. The cultivation procedure was found to have a significant impact on the performance during SSF, as well as in small-scale fermentations of hydrolysate liquor without solid material. The Baker's yeast cultivated on the hydrolysate from the steam pretreatment had in all cases a higher productivity, in particular at the highest substrate load. Cultivated Baker's yeast had a slightly higher productivity than TMB3000. The results suggest that the adaptation of the yeast to the inhibitors present in the medium is an important factor that must be considered in the design of SSF processes.
|
|
| 46. |
- Almazrouei, Mohammed, et al.
(författare)
-
Forensic Pathologists in a Pandemic : Operational, Occupational and Legal Challenges
- 2020
-
Ingår i: Forensic on the Scene and in the Lab. - : CompareNetworks.
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Nearly four months after COVID-19 was characterised as a pandemic by the World Health Organisation, its impact across different professional organizations has been pronounced. Due to the nature of the work, forensic pathologists may have been at greater risk of exposure to the virus than many other professions. In this paper, we discuss how the work of forensic pathologists dealing with deceased bodies is impacted by the COVID-19 pandemic so far. More specifically, we look into operational, occupational and legal challenges and what we may learn from them in the short and long term. Such discussions can contribute toward ensuring the health and safety of forensic pathologists and their capacity to continue to perform their critical role in the crime reconstruction process and the legitimacy of the criminal justice system.
|
|
| 47. |
- Almeida, Joao, et al.
(författare)
-
Carbon fluxes of xylose-consuming Saccharomyces cerevisiae strains are affected differently by NADH and NADPH usage in HMF reduction.
- 2009
-
Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598. ; 84, s. 751-761
-
Tidskriftsartikel (refereegranskat)abstract
- Industrial Saccharomyces cerevisiae strains able to utilize xylose have been constructed by overexpression of XYL1 and XYL2 genes encoding the NADPH-preferring xylose reductase (XR) and the NAD(+)-dependent xylitol dehydrogenase (XDH), respectively, from Pichia stipitis. However, the use of different co-factors by XR and XDH leads to NAD(+) deficiency followed by xylitol excretion and reduced product yield. The furaldehydes 5-hydroxymethyl-furfural (HMF) and furfural inhibit yeast metabolism, prolong the lag phase, and reduce the ethanol productivity. Recently, genes encoding furaldehyde reductases were identified and their overexpression was shown to improve S. cerevisiae growth and fermentation rate in HMF containing media and in lignocellulosic hydrolysate. In the current study, we constructed a xylose-consuming S. cerevisiae strain using the XR/XDH pathway from P. stipitis. Then, the genes encoding the NADH- and the NADPH-dependent HMF reductases, ADH1-S110P-Y295C and ADH6, respectively, were individually overexpressed in this background. The performance of these strains, which differed in their co-factor usage for HMF reduction, was evaluated under anaerobic conditions in batch fermentation in absence or in presence of HMF. In anaerobic continuous culture, carbon fluxes were obtained for simultaneous xylose consumption and HMF reduction. Our results show that the co-factor used for HMF reduction primarily influenced formation of products other than ethanol, and that NADH-dependent HMF reduction influenced product formation more than NADPH-dependent HMF reduction. In particular, NADH-dependent HMF reduction contributed to carbon conservation so that biomass was produced at the expense of xylitol and glycerol formation.
|
|
| 48. |
- Almeida, Joao, et al.
(författare)
-
Increased tolerance and conversion of inhibitors in lignocellulosic hydrolysates by Saccharomyces cerevisiae
- 2007
-
Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 82:4, s. 340-349
-
Forskningsöversikt (refereegranskat)abstract
- During hydrolysis of lignocellulosic biomass, monomeric sugars and a broad range of inhibitory compounds are formed and released. These inhibitors, which can be organized around three main groups, furans, weak acids and phenolics, reduce ethanol yield and productivity by affecting the microorganism performance during the fermentation step. Among the microorganisms that have been evaluated for lignocellulosic hydrolysate ethanol fermentation, the yeast Saccharomyces cerevisiae appears to be the least sensitive. In order to overcome the effect of inhibitors, strategies that include improvement of natural tolerance of microorganism and use of fermentation control strategies have been developed. An overview of the origin, effects and mechanisms of action of known inhibitors on S. cerevisiae is given. Fermentation control strategies as well as metabolic, genetic and evolutionary engineering strategies to obtain S. cerevisiae strains with improved tolerance are discussed.
|
|
| 49. |
- Almeida, Joao, et al.
(författare)
-
Metabolic effects of furaldehydes and impacts on biotechnological processes.
- 2009
-
Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598. ; 82:4, s. 625-638
-
Forskningsöversikt (refereegranskat)abstract
- There is a growing awareness that lignocellulose will be a major raw material for production of both fuel and chemicals in the coming decades-most likely through various fermentation routes. Considerable attention has been given to the problem of finding efficient means of separating the major constituents in lignocellulose (i.e., lignin, hemicellulose, and cellulose) and to efficiently hydrolyze the carbohydrate parts into sugars. In these processes, by-products will inevitably form to some extent, and these will have to be dealt with in the ensuing microbial processes. One group of compounds in this category is the furaldehydes. 2-Furaldehyde (furfural) and substituted 2-furaldehydes-most importantly 5-hydroxymethyl-2-furaldehyde-are the dominant inhibitory compounds found in lignocellulosic hydrolyzates. The furaldehydes are known to have biological effects and act as inhibitors in fermentation processes. The effects of these compounds will therefore have to be considered in the design of biotechnological processes using lignocellulose. In this short review, we take a look at known metabolic effects, as well as strategies to overcome problems in biotechnological applications caused by furaldehydes.
|
|
| 50. |
- Almeida, Joao, et al.
(författare)
-
NADH- vs NADPH-coupled reduction of 5-hydroxymethyl furfural (HMF) and its implications on product distribution in Saccharomyces cerevisiae.
- 2008
-
Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598. ; 78:6, s. 939-945
-
Tidskriftsartikel (refereegranskat)abstract
- Saccharomyces cerevisiae alcohol dehydrogenases responsible for NADH-, and NADPH-specific reduction of the furaldehydes 5-hydroxymethyl-furfural (HMF) and furfural have previously been identified. In the present study, strains overexpressing the corresponding genes (mut-ADH1 and ADH6), together with a control strain, were compared in defined medium for anaerobic fermentation of glucose in the presence and absence of HMF. All strains showed a similar fermentation pattern in the absence of HMF. In the presence of HMF, the strain overexpressing ADH6 showed the highest HMF reduction rate and the highest specific ethanol productivity, followed by the strain overexpressing mut-ADH1. This correlated with in vitro HMF reduction capacity observed in the ADH6 overexpressing strain. Acetate and glycerol yields per biomass increased considerably in the ADH6 strain. In the other two strains, only the overall acetate yield per biomass was affected. When compared in batch fermentation of spruce hydrolysate, strains overexpressing ADH6 and mut-ADH1 had five times higher HMF uptake rate than the control strain and improved specific ethanol productivity. Overall, our results demonstrate that (1) the cofactor usage in the HMF reduction affects the product distribution, and (2) increased HMF reduction activity results in increased specific ethanol productivity in defined mineral medium and in spruce hydrolysate.
|
|
