Local electronic structure of Mn dopants in ZnO probed by resonant inelastic x-ray scattering

Chang, G S,Kurmaev, E Z,Jung, S W,Kim, H-J,Yi, G-C,Lee, S-I,Yablonskikh, M V,Pedersen, T M,Moewes, A,Finkelstein, L D IOP Pub 2007 Journal of physics, an Institute of Physics journa Vol.19 No.27

<P>The electronic structure of Mn dopants in ZnO epitaxial thin films synthesized at different temperatures has been investigated using resonant inelastic x-ray scattering. The resulting Mn L<SUB>2,3</SUB> x-ray emission spectra of Zn<SUB>0.8</SUB>Mn<SUB>0.2</SUB>O (resonantly excited at L<SUB>2</SUB> and L<SUB>3</SUB> absorption edges) reveal different spectral features depending on the growth temperature of the films. The relative integral intensity ratio of Mn L<SUB>2</SUB> to Mn L<SUB>3</SUB> emission lines is greatly suppressed in the case of nonmagnetic Zn<SUB>0.8</SUB>Mn<SUB>0.2</SUB>O grown at 700 °C due to L<SUB>2</SUB>L<SUB>3</SUB>M<SUB>4,5</SUB> Coster–Kronig transitions. The ferromagnetic sample grown at 600 °C exhibits a normal oxide structure. The results suggest that a high growth temperature causes direct Mn–Mn bonds from the segregation of Mn atoms in ZnO. Therefore the disappearance of ferromagnetism in Mn-doped ZnO can be attributed to antiferromagnetic Mn–Mn exchange interactions due to the inhomogeneous local environment around the Mn impurities.</P>

Validation and Recommendation of Methods to Measure Biogas Production Potential of Animal Manure

Pham, C.H.,Triolo, J.M.,Cu, T.T.T.,Pedersen, L.,Sommer, S.G. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.6

In developing countries, biogas energy production is seen as a technology that can provide clean energy in poor regions and reduce pollution caused by animal manure. Laboratories in these countries have little access to advanced gas measuring equipment, which may limit research aimed at improving local adapted biogas production. They may also be unable to produce valid estimates of an international standard that can be used for articles published in international peer-reviewed science journals. This study tested and validated methods for measuring total biogas and methane ($CH_4$) production using batch fermentation and for characterizing the biomass. The biochemical methane potential (BMP) ($CH_4$ NL $kg^{-1}$ VS) of pig manure, cow manure and cellulose determined with the Moller and VDI methods was not significantly different in this test (p>0.05). The biodegradability using a ratio of BMP and theoretical BMP (TBMP) was slightly higher using the Hansen method, but differences were not significant. Degradation rate assessed by methane formation rate showed wide variation within the batch method tested. The first-order kinetics constant k for the cumulative methane production curve was highest when two animal manures were fermented using the VDI 4630 method, indicating that this method was able to reach steady conditions in a shorter time, reducing fermentation duration. In precision tests, the repeatability of the relative standard deviation (RSDr) for all batch methods was very low (4.8 to 8.1%), while the reproducibility of the relative standard deviation (RSDR) varied widely, from 7.3 to 19.8%. In determination of biomethane concentration, the values obtained using the liquid replacement method (LRM) were comparable to those obtained using gas chromatography (GC). This indicates that the LRM method could be used to determine biomethane concentration in biogas in laboratories with limited access to GC.

Safety guidelines of ultimate hull girder strength for grounded container ships

Kim, D.K.,Pedersen, P.T.,Paik, J.K.,Kim, H.B.,Zhang, X.,Kim, M.S. Elsevier 2013 Safety science Vol.59 No.-

Various accidents commonly occur on operating ships. The structural damage caused by such accidents is often accompanied by casualties and serious pollution. In this regard, an accidental risk-based approach that is in line with the Goal Based Standard (GBS) of the International Maritime Organization (IMO) is being developed in the literature. In this paper, the residual ultimate longitudinal strength versus grounding damage index diagram (R-D diagram) for container ships is established as per the method of Paik et al. (2012). The proposed R-D diagram should be useful for defining acceptance damage criteria and making rapid salvage plans or rescue schemes for container ships that have sustained a grounding accident.

Biogas Production from Vietnamese Animal Manure, Plant Residues and Organic Waste: Influence of Biomass Composition on Methane Yield

T.T.T. Cu,T.X. Nguyen,J.M. Triolo,L. Pedersen,V.D. Le,P.D. Le,S.G. Sommer 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.2

Anaerobic digestion is an efficient and renewable energy technology that can produce biogas from a variety of biomasses such as animal manure, food waste and plant residues. In developing countries this technology is widely used for the production of biogas using local biomasses, but there is little information about the value of these biomasses for energy production. This study was therefore carried out with the objective of estimating the biogas production potential of typical Vietnamese biomasses such as animal manure, slaughterhouse waste and plant residues, and developing a model that relates methane (CH4) production to the chemical characteristics of the biomass. The biochemical methane potential (BMP) and biomass characteristics were measured. Results showed that piglet manure produced the highest CH4 yield of 443 normal litter (NL) CH4 kg–1 volatile solids (VS) compared to 222 from cows, 177 from sows, 172 from rabbits, 169 from goats and 153 from buffaloes. Methane production from duckweed (Spirodela polyrrhiza) was higher than from lawn grass and water spinach at 340, 220, and 110.6 NL CH4 kg–1 VS, respectively. The BMP experiment also demonstrated that the CH4 production was inhibited with chicken manure, slaughterhouse waste, cassava residue and shoe-making waste. Statistical analysis showed that lipid and lignin are the most significant predictors of BMP. The model was developed from knowledge that the BMP was related to biomass content of lipid, lignin and protein from manure and plant residues as a percentage of VS with coefficient of determination (R-square) at 0.95.This model was applied to calculate the CH4 yield for a household with 17 fattening pigs in the highlands and lowlands of northern Vietnam.

Properties of Cylindrical Brush Polymers

Manfred Schmidt,Bin Zhang,Karl Fischerl,Franziska Grohn,J. S. Pedersen 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10

Biogas Production from Vietnamese Animal Manure, Plant Residues and Organic Waste: Influence of Biomass Composition on Methane Yield

Cu, T.T.T.,Nguyen, T.X.,Triolo, J.M.,Pedersen, L.,Le, V.D.,Le, P.D.,Sommer, S.G. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.2

Anaerobic digestion is an efficient and renewable energy technology that can produce biogas from a variety of biomasses such as animal manure, food waste and plant residues. In developing countries this technology is widely used for the production of biogas using local biomasses, but there is little information about the value of these biomasses for energy production. This study was therefore carried out with the objective of estimating the biogas production potential of typical Vietnamese biomasses such as animal manure, slaughterhouse waste and plant residues, and developing a model that relates methane ($CH_4$) production to the chemical characteristics of the biomass. The biochemical methane potential (BMP) and biomass characteristics were measured. Results showed that piglet manure produced the highest $CH_4$ yield of 443 normal litter (NL) $CH_4kg^{-1}$ volatile solids (VS) compared to 222 from cows, 177 from sows, 172 from rabbits, 169 from goats and 153 from buffaloes. Methane production from duckweed (Spirodela polyrrhiza) was higher than from lawn grass and water spinach at 340, 220, and 110.6 NL $CH_4kg^{-1}$ VS, respectively. The BMP experiment also demonstrated that the $CH_4$ production was inhibited with chicken manure, slaughterhouse waste, cassava residue and shoe-making waste. Statistical analysis showed that lipid and lignin are the most significant predictors of BMP. The model was developed from knowledge that the BMP was related to biomass content of lipid, lignin and protein from manure and plant residues as a percentage of VS with coefficient of determination (R-square) at 0.95.This model was applied to calculate the $CH_4$ yield for a household with 17 fattening pigs in the highlands and lowlands of northern Vietnam.