| 1. |
- Bielewicz, M., et al.
(författare)
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(n,xn) cross section measurements for Y-89 foils used as detectors for high energy neutron measurements in the deeply subcritical assembly “QUINTA”
- 2017
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Ingår i: ND 2016: INTERNATIONAL CONFERENCE ON NUCLEAR DATA FOR SCIENCE AND TECHNOLOGY. - Les Ulis : EDP Sciences. - 9782759890200
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Konferensbidrag (refereegranskat)abstract
- Study of the deep subcritical systems (QUINTA) using relativistic beams is performed within the project “Energy and Transmutation of Radioactive Wastes” (E&T – RAW). The experiment assembly was irradiated by deuteron/proton beam (Dubna NUCLOTRON). We calculated the neutron energy spectrum inside the whole assembly by using threshold energy (n,xn) reactions in yttrium (Y-89) foils. There are almost no experimental cross section data for those reactions. New Y-89(n,xn) cross section measurements were carried out at The Svedberg laboratory (TSL) in Uppsala, Sweden in 2015. In this paper we present preliminary results of those experiments.
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| 2. |
- Blomqvist, Johanna, et al.
(författare)
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Fermentation of lignocellulosic hydrolysate by the alternative industrial ethanol yeast Dekkera bruxellensis
- 2011
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Ingår i: Letters in Applied Microbiology. - Malden, USA : Wiley-Blackwell. - 0266-8254 .- 1472-765X. ; 53:1, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- Aim: Testing the ability of the alternative ethanol production yeast Dekkera bruxellensis to produce ethanol from lignocellulose hydrolysate and comparing it to Saccharomyces cerevisiae.Methods and Results: Industrial isolates of D. bruxellensis and S. cerevisiae were cultivated in small-scale batch fermentations of enzymatically hydrolysed steam exploded aspen sawdust. Different dilutions of hydrolysate were tested. None of the yeasts grew in undiluted or 1 : 2 diluted hydrolysate [final glucose concentration always adjusted to 40 g l(-1) (0.22 mol l(-1))]. This was most likely due to the presence of inhibitors such as acetate or furfural. In 1 : 5 hydrolysate, S. cerevisiae grew, but not D. bruxellensis, and in 1 : 10 hydrolysate, both yeasts grew. An external vitamin source (e.g. yeast extract) was essential for growth of D. bruxellensis in this lignocellulosic hydrolysate and strongly stimulated S. cerevisiae growth and ethanol production. Ethanol yields of 0 42 +/- 0 01 g ethanol (g glucose)(-1) were observed for both yeasts in 1 : 10 hydrolysate. In small-scale continuous cultures with cell recirculation, with a gradual increase in the hydrolysate concentration, D. bruxellensis was able to grow in 1 : 5 hydrolysate. In bioreactor experiments with cell recirculation, hydrolysate contents were increased up to 1 : 2 hydrolysate, without significant losses in ethanol yields for both yeasts and only slight differences in viable cell counts, indicating an ability of both yeasts to adapt to toxic compounds in the hydrolysate.Conclusions: Dekkera bruxellensis and S. cerevisiae have a similar potential to ferment lignocellulose hydrolysate to ethanol and to adapt to fermentation inhibitors in the hydrolysate.Significance and Impact of the study: This is the first study investigating the potential of D. bruxellensis to ferment lignocellulosic hydrolysate. Its high competitiveness in industrial fermentations makes D. bruxellensis an interesting alternative for ethanol production from those substrates.
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| 3. |
- Lyberg, K., et al.
(författare)
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Biochemical and microbiological properties of a cereal mix fermented with whey, wet wheat distillers' grain or water at different temperatures
- 2008
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Ingår i: Animal Feed Science and Technology. - Amsterdam, Netherlands : Elsevier. - 0377-8401 .- 1873-2216. ; 144:1-2, s. 137-148
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Tidskriftsartikel (refereegranskat)abstract
- Microbiological and biochemical properties of three different liquid diets fermented at 10, 15 or 20 degrees C were studied. The liquid diets consisted of a cereal grain mix of wheat, barley and triticale, blended with whey (diet WH), wet wheat distillers' grain (diet WDG) or water (diet WAT). The diets were fermented for 5 days without disturbance, followed by 14 days of daily feed replacements, where 4/5 of the contents were replaced with fresh feed mixtures. Starting pH values were 5.1, 3.9 and 6.3 in WH, WDG and WAT, respectively. For most diets, the pH decreased to approximately 4.0 by day 5. However, the WAT diet fermented at 10 degrees C required 7 days to reach a pH of 4.0. A higher (P < 0.001) pH was seen in the WH diet fermented at 10 degrees C than in the other diets. Composition of the diets was determined during day 17-19 of fermnentation to allow the microbial populations to stabilise and to reflect conditions in practice. Lactic acid bacteria (LAB) grew in all diets during fermentation and the growth was affected by temperature and type of diet (P < 0.001), and the interaction between these two factors (P < 0.001). The highest LAB counts were found at higher temperatures in the WAT and WH diets and the lowest counts were found in diet WDG. The highest levels of acetic, succinic and propionic acids were found in diet WDG (P < 0.001). Lactic acid concentrations increased with temperature (P < 0.001) and were highest in the WAT and WH diets. In vitro digestibility of organic matter was highest for diet WH and lowest for diet WDG (P < 0.001). Inositol hexaphosphate-bound phosphorus (P) and total P in the cereal grain mix were 2.2 and 3.7 g kg(-1) dry matter, respectively. No inositol phosphate-bound P was found in any of the diets after fermentation. Some moulds, probably originating from spores in the cereal grain mix, were delected in the fermented diets, but total numbers did not increase with time. Enterobacteriaceae detected in diet WH, probably originated from the cereal grain mix and the whey. Yeasts were present in all diet ingredients. In conclusion, fermentation processes and biochemical properties differed greatly due to temperature, type of diet and the interaction of these two factors. Dietary inositol hexaphosphate was completely degraded in all fermented diets. (c) 2007 Elsevier B.V. All rights reserved.
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| 4. |
- Passoth, V., et al.
(författare)
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Biotechnology, physiology and genetics of the yeast Pichia anomala
- 2006
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Ingår i: FEMS yeast research (Print). - Oxon, United Kingdom : Blackwell Publishing. - 1567-1356 .- 1567-1364. ; 6:1, s. 3-13
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Forskningsöversikt (refereegranskat)abstract
- The ascomycetous yeast Pichia anomala is frequently associated with food and feed products, either as a production organism or as a spoilage yeast. It belongs to the nonSaccharomyces wine yeasts and contributes to the wine aroma by the production of volatile compounds. The ability to grow in preserved food and feed environments is due to its capacity to grow under low pH, high osmotic pressure and low oxygen tension. A new application of P. anomala is its use as a biocontrol agent, which is based on the potential to inhibit a variety of moulds in different environments. Although classified as a biosafety class-1 organism, cases of P. anomala infections have been reported in immunocompromised patients. On the other hand, P. anomala killer toxins have a potential as antimicrobial agents. The yeast can use a broad range of nitrogen and phosphor sources, which makes it a potential agent to decrease environmental pollution by organic residues from agriculture. However, present knowledge of the physiological basis of its performance is limited. Recently, the first studies have been published dealing with the global regulation of the metabolism of P. anomala under different conditions of oxygenation.
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| 5. |
- Pola, A., et al.
(författare)
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Compact Thermal Neutron Sensors for Moderator-Based Neutron Spectrometers
- 2014
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Ingår i: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 0144-8420 .- 1742-3406. ; 161:1-4, s. 229-232
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Tidskriftsartikel (refereegranskat)abstract
- In the framework of the NESCOFI@BTF project of the Italian Institute of Nuclear Physics, different types of active thermal neutron sensors were studied by coupling semiconductor devices with a suitable radiator. The objective was to develop a detector of small dimensions with a proper sensitivity to use at different positions in a novel moderating assembly for neutron spectrometry. This work discusses the experimental activity carried out in the framework of the ERINDA program (PAC 3/9 2012) to characterise the performance of a thermal neutron pulse detector based on Li-6.
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