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- Arshadi, Mehrdad, et al.
(författare)
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Production of energy from biomass
- 2008
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Ingår i: Introduction to chemicals from biomass. - : John Wiley & Sons. - 9780470058053 ; , s. 143-178
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Bokkapitel (refereegranskat)
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| 2. |
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| 4. |
- Fei, Xiaowen, et al.
(författare)
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An Fe deficiency responsive element with a core sequence of TGGCA regulates the expression of FEA1 in Chlamydomonas reinharditii
- 2009
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Ingår i: Journal of biochemistry. - Oxford, UK : Oxford University Press. - 1756-2651 .- 0021-924X. ; 146:2, s. 157-166
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Tidskriftsartikel (refereegranskat)abstract
- Iron is essential to the unicellular green alga Chlamydomonas, but the molecular mechanism for response to iron deficiency remains largely unknown. In previous studies, we have identified FOX1 and ATX1 FEREs (Fe deficiency-responsive elements) as important regulation components of iron response in this organism. Here we present another iron regulated gene FEA1, which promoter was analysed by using a 5'-and 3'-end deletion and a scanning mutagenesis assay. The results reveal that the co-existence of -273/-188 and -118/-49 regions from transcriptional start site of FEA1 were sufficient and necessary for Fe deficiency-induced expression. Further deletion analysis indicates both -273/-253 and -103/-85 regions are essential for inducible expression. The scanning mutagenesis analysis of these regions identifies two cis-acting elements: the FeaFeRE1 at -273/-259 (CTGCGGTGGCAAAGT) and FeaFeRE2 at -106/-85 (CCGCCGCNNNTGGCACCAGCCT). Sequence comparison of FeaFeRE1 and FeaFeRE2 reveals a core sequence of TGGCA, which had been found in our previously reported Fe-deficiency-inducible gene ATX1. Moreover, we show that the promoter region of several genes, including FRE1, IRT1, ISCA, ZRT1, ZRT5, NRAMP2 and COPT1, also contains this core sequence, suggesting that at least two classes FeRE elements exist in Clamydomonas, one in FEA1 and ATX1 and others the second in FOX1, FEA2, MTP4, NRAMP3 and RBOL1.
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| 7. |
- Mahanta, C., et al.
(författare)
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Source, distribution and release mechanisms of arsenic in the groundwater of Assam floodplains of Northeast India
- 2008
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Ingår i: World Environmental and Water Resources Congress 2008: Ahupua'a - Proceedings of the World Environmental and Water Resources Congress 2008. - Reston, VA : American Society of Civil Engineers. - 9780784409763
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Konferensbidrag (refereegranskat)abstract
- This study conducted in Bongaigaon and Darrang districts of Assam, India is based upon water chemistry and sediment characteristics investigation in an reportedly arsenic infested belt. Of total 50 sampled wells, 15 had arsenic concentration above national drinking water standard of 50 μg/l, and 33 had As concentrations above the WHO guideline of 10 μg/l. However no distinct zones or depths with specific sedimentological features could be identified. Sediments with colour on green-olive scale are probably more likely to bear As contaminated water than white sediments. Sand filters used to reduce high iron content seem to reduce As content of water effectively. Arsenic rich water is also partly avoided since drillers seek water low in iron, which is often also low in arsenic content. Reductive dissolution of Ferric hydroxides is believed to be the release mechanism controlling the mobility of arsenic, rather than oxidation of arsenopyrite or pH induced desorption.
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| 8. |
- Odlare, Monica, et al.
(författare)
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Changes in soil chemical and microbiological properties during 4 years of application of various organic residues
- 2008
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Ingår i: Waste Management. - : Elsevier. - 0956-053X .- 1879-2456. ; 28:7, s. 1246-1253
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Tidskriftsartikel (refereegranskat)abstract
- A 4-year field trial was established in eastern Sweden to evaluate the effects of organic waste on soil chemical and microbiological variables. A simple crop rotation with barley and oats was treated with either compost from household waste, biogas residue from household waste, anaerobically treated sewage sludge, pig manure, cow manure or mineral fertilizer. All fertilizers were amended in rates corresponding to 100 kg N ha-1 year-1. The effects of the different types of organic waste were evaluated by subjecting soil samples, taken each autumn 4 weeks after harvest, to an extensive set of soil chemical (pH, Org-C, Tot-N, Tot-P, Tot-S, P-AL, P-Olsen, K-AL, and some metals) and microbiological (B-resp, SIR, μSIR active and dormant microorganisms, PDA, μPDA, PAO, Alk-P and N-min) analyses. Results show that compost increased pH, and that compost as well as sewage sludge increased plant available phosphorus; however, the chemical analysis showed few clear trends over the 4 years and few clear relations to plant yield or soil quality. Biogas residues increased substrate induced respiration (SIR) and, compared to the untreated control amendment of biogas residues as well as compost, led to a higher proportion of active microorganisms. In addition, biogas residues increased potential ammonia oxidation rate (PAO), nitrogen mineralization capacity (N-min) as well as the specific growth rate constant of denitrifiers (μPDA). Despite rather large concentrations of heavy metals in some of the waste products, no negative effects could be seen on either chemical or microbiological soil properties. Changes in soil microbial properties appeared to occur more rapidly than most chemical properties. This suggests that soil microbial processes can function as more sensitive indicators of short-term changes in soil properties due to amendment of organic wastes.
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| 9. |
- Rhén, Christofer, et al.
(författare)
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Effect of raw material composition in woody biomass pellets on combustion characteristics
- 2007
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Ingår i: Biomass and Bioenergy. - Oxford : Pergamon Press. - 0961-9534 .- 1873-2909. ; 31:1, s. 66-72
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Tidskriftsartikel (refereegranskat)abstract
- Char yield, char combustion time and char combustion rate of pellets made from different tree parts of Norway spruce and industrially made stem wood pellets of Norway spruce and Scots pine were studied. The pellets were incinerated in a laboratory scale oven at various temperatures, gas flows and oxygen concentrations. It was found that the combustion time for a single pellet mostly depended on the raw material composition and to a minor extent on the density. Pellets made of bark had up to a 50% longer char combustion time compared to that of stem wood pellets, due to differences in char yield. Industrially made stem wood pellets of pine and spruce sawdust were found to have small differences in combustion characteristics. The variations in combustion characteristics of pellets are discussed in relation to composition of raw material.
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