6,294 research outputs found
Nitrogen fertilizer value of digestates from anaerobic digestion of animal manures and crops
After anaerobic digestion (AD) of manures for biogas production the concentration of ammonium-N is increased and the concentration of decomposable carbon in manure is decreased. That implies that the first year fertilizer value of the manure can be increased by the treatment. However, pH is also increased by AD thereby increasing the risk of ammonia losses while the lowered dry matter content on the other hand improves the manure infiltration in soil and reduces the risk of ammonia loss. Therefore the effects of AD on plant N availability can be expected to interact with the manure application method used.
In stockless organic farming it has been suggested that nitrogen utilization can be improved by using anaerobic digestion of plant-based green manures, but the information about such manures is scarce.
We have compared nitrogen fertilizer values of 1) pig and cattle slurries before and after AD and 2) digested plant-based manures. Mineral fertilizer replacement values (MFRV) were determined after direct injection to barley and oats crops and after surface-banding in a winter wheat crop.
The manures were digested in continuously fed pilot digesters at thermophilic conditions (ca. 50°C). The manures were applied to small framed plots and grain yields and N uptake were compared to plots receiving increasing amounts of mineral N fertilizer. The three tested plant-based manures derived from crops of either grass clover, yellow lupine or a triticale-winter vetch mixture.
The MFRV of total N in two different injected cattle slurries increased from 58-75% to 69-82% after AD. The MFRV of cattle slurry after surface-banding in winter wheat was much lower: 30-37% for untreated slurry and 38-49% after AD. The low availability after surface-banding can be ascribed to high ammonia volatilization. The MFRV of injected pig slurry was high and similar with and without AD: 89-91%. After surface banding of pig slurry MFRV was 75% for untreated and 87% for digested pig slurry.
The plant-based manures contained a high proportion of ammonium-N (59-68% of total N) after AD and the MFRVs of total manure N were comparable to the digested cattle slurries: 73-77% after injection, but only 43-57% after surface-banding of the manure.
The influence of AD of manure on N turnover in soil has also been evaluated in a soil incubation study with some of the same manures, and the differences between untreated and digested manures were more distinct in this incubation study than the observed differences in fertilizer value.
We conclude that the potential plant availability of pig and cattle slurry can be increased by 10-15% points after AD. However, after surface-banding of digested manures rich in fibers, such as cattle and plant-based manures, significant ammonia loss can be expected resulting in relative poor N utilization
Relativity accommodates superluminal mean velocities
Contrary to a widespread belief, measures of velocity can yield a value
larger than , the instantaneous light speed in vacuum, without contradicting
Einstein's relativity. Nevertheless, the effect turns out to be too small to
explain the recently claimed superluminal velocity by the OPERA collaboration.
Several other general relativistic effects acting on the OPERA neutrinos are
also analyzed. All of them are unable to explain the OPERA result.Comment: 5 pages; Latex source, 2 eps figures (expanded discussion, a few
typos corrected, some refs. added
Cosmogenic Neutrinos Through the GRAND Lens Unveil the Nature of Cosmic Accelerators
The sources of cosmic rays with energies above 55 EeV are still mysterious. A
guaranteed associated flux of ultra high energy neutrinos known as the
cosmogenic neutrino flux will be measured by next generation radio facilities,
such as the proposed Giant Radio Array for Neutrino Detection (GRAND). By using
the orthogonal information provided by the cosmogenic neutrino flux, we here
determine the prospects of GRAND to constrain the source redshift evolution and
the chemical composition of the cosmic ray sources. If the redshift evolution
is known, independently on GRAND's energy resolution, GRAND with 200,000
antennas will constrain the proton/iron fraction to the level
after one year of data taking; on the other hand, if hints on the average
source composition are given, GRAND will measure the redshift evolution of the
sources to a uncertainty. However, the foreseen configuration of
GRAND alone will not be able to break the degeneracy between redshift evolution
of the sources and their composition. Our findings underline the discriminating
potential of next generation radio array detectors and motivate further efforts
in this direction.Comment: 18 pages, 6 figures, 1 table, comments welcome; clarifying comments
added, matches published versio
Grain Characteristics, Chemical Composition, and Functional Properties of Rye (Secale cereale L.) As Influenced by Genotype and Harvest Year
Grain characteristic, chemical composition, and functional properties of rye were measured in 19 different cultivars grown in one location in up to 3 years. The cultivars included 8 adapted hybrids, 7 adapted population cultivars, and 4 nonadapted population cultivars. The results showed a significant influence of both harvest year and genotype on grain characteristics, chemical composition, and functional properties of the grain. Multivariate data analysis confirmed that the variations in the data were explained by yearly and genotype differences. Calculations of variance components showed that the variations in plant height, harvest yield, and protein content were mainly due to genotype differences and to a lesser extent to differences among harvest years. The kernel weight, hardness index, and content of dietary fiber components, however, were more strongly influenced by the harvest year than by the genotype. Differences in starch properties measured by falling number (FN), amylograph peak viscosity, and temperature at peak viscosity were more strongly influenced by harvest year. The water absorption was strongly influenced by genotype effects, compared to yearly differences. FN and amylograph peak temperature were positively correlated (r = 0.94). No correlation was found between the water absorption and the relative proportion of water-extractable arabinoxylan (AX) compared to the total AX content. However, the degree of ferulic acid cross-linking showed a negative correlation (r = -0.70) with the water absorption
Multimode optomechanical system in the quantum regime
We realise a simple and robust optomechanical system with a multitude of
long-lived () mechanical modes in a phononic-bandgap shielded membrane
resonator. An optical mode of a compact Fabry-Perot resonator detects these
modes' motion with a measurement rate () that exceeds the
mechanical decoherence rates already at moderate cryogenic temperatures
(). Reaching this quantum regime entails, i.~a., quantum
measurement backaction exceeding thermal forces, and thus detectable
optomechanical quantum correlations. In particular, we observe ponderomotive
squeezing of the output light mediated by a multitude of mechanical resonator
modes, with quantum noise suppression up to -2.4 dB (-3.6 dB if corrected for
detection losses) and bandwidths . The multi-mode
nature of the employed membrane and Fabry-Perot resonators lends itself to
hybrid entanglement schemes involving multiple electromagnetic, mechanical, and
spin degrees of freedom.Comment: 19 pages, 9 figure
Renovation with Internal Insulation and Heat Recovery in Real Life– Energy Savings and Risk of Mold Growth
This paper presents a pilot project for renovation of a large residential area; focus is on energy consumption and risk of mold growth. The renovation included internal insulation of walls with capillary active insulation material, balanced mechanical ventilation with heat recovery and insulation of floor towards basement. These types of measures are not completely new and have been used in other buildings as well, however the measures may be either risky regarding mold growth or the effect is uncertain with the specific external wall composition. A pilot project including six apartments was performed to test the measures in these specific buildings. Furthermore, six reference apartments were monitored simultaneously. For two years, energy use for heating was measured as well as temperature and relative humidity in the internal insulation, indoors and outside. The insulation was dismantled in two apartments after two years, to test for mold growth at the original wall surface. In extreme cases, the relative humidity in the walls behind the insulation system was up to 90 % RH shortly after installation, and mold growth models predicted growth of mold. However, the relative humidity decreased, typically to 70 % RH in the second winter. The inspection and measurements after the removal of the insulation material did not show signs of mold growth. Apparently, the used insulation material can be used in this specific case without risk of mold growth. Energy savings for heating was measured and calculated to around 25 %. However, the electricity use for ventilation was almost equal to savings from heat recovery
Rising damp, a reoccurring problem in basements:a case study with different attempts to stop the moisture
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