3941. |
3942. Cadmium associates with oxalate in calcium oxalate crystals and competes with calcium for translocation to stems in the cadmium bioindicator Gomphrena clausseniiPaula Pongrac, Tania Serra, Hiram Castillo Michel, Katarina Vogel-Mikuš, Iztok Arčon, Mitja Klemen, Boštjan Jencic, Anja Kavčič, Mina T. Villafort Carvalho, Mark G. M. Aarts, 2018, original scientific article Abstract: Cadmium (Cd) was shown to co-localise with calcium (Ca) in oxalate crystals in the stems and leaves of
Cd tolerant Gomphrena claussenii, but Cd binding remained unresolved. Using synchrotron radiation
X-ray absorption near edge spectroscopy we demonstrate that in oxalate crystals of hydroponically
grown G. claussenii the vast majority of Cd is bound to oxygen ligands in oxalate crystals (488%;
Cd–O–C coordination) and the remaining Cd is bound to sulphur ligands (Cd–S–C coordination). Cadmium
binding to oxalate does not depend on the amount of Ca supplied or from which organs the crystals
originate (stems and mature leaves). By contrast, roots contain no oxalate crystals and therein Cd is
bound predominantly by S ligands. The potential to remove Cd by extraction of Cd-rich oxalate crystals
from plant material should be tested in phytoextraction or phytomining strategies.
Keywords: Cd XANES, Cd oxalate, Gomphrena claussenii
Published in RUNG: 06.09.2018; Views: 3345; Downloads: 0
This document has many files! More... |
3943. How to react to the necessity of a sustainable animal production? The EcoLamb projectTanja Peric, Martina Bergant Marušič, Ario De Marco, Petra Makorič, Sinan Ogun, 2018, published scientific conference contribution abstract Abstract: EcoLamb assesses the sustainability of diverse European sheep production systems focusing on the ecological footprint, animal welfare aspects and nutrition value of lamb meat. The outcomes of these assessments will be used to understand the potential future barriers that limit the innovative capacity and development of the sector and the opportunities that may provide a future market niche against competitive products from other global markets. Farm solutions that incorporate consumer expectations for animal welfare and meat quality will enhance the competitiveness of Europe's lamb meat sector. The project engages trans-national research and industry stakeholders from 6 countries made up of Germany, Italy, Portugal, Slovenia, Spain and Turkey to analyse on 20 case study farms resource-efficient, competitive and low-carbon lamb production models. Direct linkage between animal welfare, meat quality and pharmaceutical use will also be determined using innovative Precision Farming techniques. The project will produce a tool-box of recommendations for productive sheep farm management, supply chain and marketing on how to improve the acceptability of lamb meat by consumers. Thus, the multidisciplinary approach and the multi-actor involvement of the EU sheep sector will assist in re-designing critical aspects to increase society acceptance and the place of lamb meat in future diets and the outcomes of the project will be used by stakeholders to promote changes in farm management, marketing and processing of meat from sheep. Additionally, results will be used by farm consultants, farmer groups and policy officers to re-design consulting approaches and plan new initiatives to make all aspects of the European sheep industry more sustainable.
Keywords: sustainable, animal production, lamb, sheep, Jezersko-Solčavska, EcoLamb
Published in RUNG: 05.09.2018; Views: 3661; Downloads: 0
This document has many files! More... |
3944. |
3945. |
3946. |
3947. |
3948. |
3949. Effects of Different Copper Loadings on the Photocatalytic Activity of TiO2-SiO2 Prepared at a Low Temperature for the Oxidation of Organic Pollutants in WaterT. Čižmar, Iztok Arčon, Mattia Fanetti, Urška Lavrenčič Štangar, 2018, original scientific article Abstract: The objective of this research is to examine how Cu modification can improve the photocatalytic activity of TiO2-SiO2, to explainthe correlation between the Cu concentration and the chemical state of Cu cations in the TiO2-SiO2 matrix, and the photocatalytic activity under UV/solar irradiation. The Cu-modified TiO2-SiO2 photocatalysts were prepared by a low-temperature sol–gel method from organic Cu, Si and Ti precursors with various Cu concentrations (0.05–3 mol %). The sol–gels were dried at 150 8C to obtain the photocatalysts in a powder form. The photocatalytic activity was determined by using a fluorescence- based method of terephthalic acid decomposition. An up to three times increase in photocatalytic activity is obtained if the TiO2-SiO2 matrix is modified with Cu in a narrow concentration
range from 0.05 to 0.1 mol%. At higher Cu loadings,
the photocatalytic activity of the Cu-modified photocatalysts is lower than that of the un-modified reference TiO2-SiO2 photocatalyst. XRD was used to show that all Cu-modified TiO2-SiO2 composites with different Cu concentrations have the same crystalline structure as un-modified TiO2-SiO2 composites. The addition of Cu does not change the relative ratio between the anatase and brookite phases or unit cell parameters of the two TiO2 crystalline structures. We used Cu K-edge X-ray absorption near edge structure and extended X-ray absorption fine structure analyses to determine the valence state and local structure of Cu cations in the Cu-modified TiO2-SiO2 photocatalysts. The results elucidate the mechanism responsible for the improved photocatalytic activity. In samples with a low Cu content,
which exhibit the highest activity, Cu@O@Ti connections
are formed, which suggests that the activity enhancement is
caused by the attachment of CuII cations on the surface of the photocatalytically active TiO2 nanoparticles, so CuII cations may act as free-electron traps, which reduce the intensity of recombination between electrons and holes at the TiO2 photocatalyst surface. At higher Cu loadings no additional Cu@O@Ti connections are formed, instead only Cu@O@Cu connections are established. This indicates the formation of amorphous or nanocrystalline
copper oxide, which hinders the photocatalytic activity
of TiO2.
Keywords: Cu modified TiO2-SiO2 photocatalyst
Cu EXAFS, XANES, Organic pollutants
Published in RUNG: 30.08.2018; Views: 3593; Downloads: 0
This document has many files! More... |
3950. |
