Anaerobic digestion experiment using Cynara cardunculus L. stalks

RAMIRAN International ConferenceAnaerobic digestion is an industrial process applied to organic wastes treatment with several environmental and energetic advantages over other forms of treatment and specially when is integrated in the agriculture sector (Möller, 2009; Prochnow, 2009; Chynoweth, 1987). In addition to the organic wastes treatment there is an emerging interest in the production of biomethane as a biocombustible through anaerobic digestion of biomass and / or energy crops (IEA, 2010; Chanakya, 2009; CONCAWE, 2008; Tilche, 2008; Yadvika, 2004; Gunaseelan, 1997; Chynoweth, 1987). Cynara cardunculus L. or commonly known as cardoon is a perennial herb or herbaceous crop native to Mediterranean region, grown since ancient times as a wild plant or as vegetable using intensive management techniques (Ortega, 2007; Fernández, 2006). The average biomass annual production varies from 15 to 20 tons of biomass/ha depending on soil and rainfall with 11% of moisture content and the following biomass partitioning: 40 % stalks, 25% leaves and 35 % capitula (Gominho, 2001 and 2008). Different studies have been shown the high potential of this plant as energy crop: the aerial biomass used as a solid biofuel and the oil from seeds used for the production of biodiesel (Fernández, 2006). However, the interest in their use in the production of biomethane has never been investigated. Different studies show that the addition of biomass or energy crops to the anaerobic digestion of cattle dung or the anaerobic digestion of energy crops residues with the addition of partially digested cattle dung or sewage digested sludge enhanced biogas production and methane yield (Chanakya, 2009; Yadvika, 2004). The goal of the research performed on Cynara cardunculus L. was to increase the knowledge about the use of this promising industrial crop for biogas production in Mediterranean countries or countries with similar edaphoclimate condition

Calculations of parity nonconserving s-d transitions in Cs, Fr, Ba II, and Ra II

We have performed ab initio mixed-states and sum-over-states calculations of parity nonconserving (PNC) electric dipole (E1) transition amplitudes between s-d electron states of Cs, Fr, Ba II, and Ra II. For the lower states of these atoms we have also calculated energies, E1 transition amplitudes, and lifetimes. We have shown that PNC E1 transition amplitudes between s-d states can be calculated to high accuracy. Contrary to the Cs 6s-7s transition, in these transitions there are no strong cancelations between different terms in the sum-over-states approach. In fact, there is one dominating term which deviates from the sum by less than 20%. This term corresponds to an s-p_{1/2} weak matrix element, which can be calculated to better than 1%, and a p_{1/2}-d_{3/2} E1 transition amplitude, which can be measured. Also, the s-d amplitudes are about four times larger than the corresponding s-s transitions. We have shown that by using a hybrid mixed-states/sum-over-states approach the accuracy of the calculations of PNC s-d amplitudes could compete with that of Cs 6s-7s if p_{1/2}-d_{3/2} E1 amplitudes are measured to high accuracy.Comment: 15 pages, 8 figures, submitted to Phys. Rev.

Differences in gait complexity and variability between children with and without Developmental Coordination Disorder

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