9,362 research outputs found
Improving Biomethanation of Chicken Manure by Co-Digestion with Ethanol Plant Effluent
As the global production of chicken manure has steadily increased, its proper management has become a challenging issue. This study examined process effluent from a bioethanol plant as a co-substrate for efficient anaerobic digestion of chicken manure. An anaerobic continuous reactor was operated in mono- and co-digestion modes by adding increasing amounts of the ethanol plant effluent (0%, 10%, and 20% (v/v) of chicken manure). Methanogenic performance improved significantly in terms of both methane production rate and yield (by up to 66% and 36%, respectively), with an increase in organic loading rate over the experimental phases. Correspondingly, the specific methanogenic activity was significantly higher in the co-digestion sludge than in the mono-digestion sludge. The reactor did not suffer any apparent process imbalance, ammonia inhibition, or nutrient limitation throughout the experiment, with the removal of volatile solids being stably maintained (56.3???58.9%). The amount of ethanol plant effluent appears to directly affect the rate of acidification, and its addition at ???20% (v/v) to chicken manure needs to be avoided to maintain a stable pH. The overall results suggest that anerobic co-digestion with ethanol plant effluent may provide a practical means for the stable treatment and valorization of chicken manure
Space-frequency model of amplified spontaneous emission and super-radiance in free electron laser operating in the linear and non-linear regimes
A three-dimensional, space-frequency model for the excitation of
electromagnetic radiation in a free-electron laser is presented. The approach
is applied in a numerical particle code WB3D, simulating the interaction of a
free-electron laser operating in the linear and non-linear regimes. Solution of
the electromagnetic excitation equations in the frequency domain inherently
takes into account dispersive effects arising from the cavity and the gain
medium. Moreover, it facilitates the consideration of statistical features of
the electron beam and the excited radiation, necessary for the study of
spontaneous emission, synchrotron amplified spontaneous emission (SASE),
super-radiance and noise. We employ the code to study the statistical and
spectral characteristics of the radiation generated in a pulsed beam
free-electron laser operating in the millimeter wavelengths. The evolution of
radiation spectrum, excited when a Gaussian shaped bunch with a random
distribution of electrons is passing through the wiggler, was investigated.Comment: 9 page
Control of the entanglement of a two-level atom in a dissipative cavity via a classical field
We investigate the entanglement dynamics and purity of a two-level atom,
which is additionally driven by a classical field, interacting with a coherent
field in a dissipative environment. It is shown that the amount of entanglement
and the purity of the system can be improved by controlling the classical
field.Comment: 5 pages, 4 figure
Phonetic variability and grammatical knowledge: an articulatory study of Korean place assimilation.
The study reported here uses articulatory data to investigate Korean place assimilation
of coronal stops followed by labial or velar stops, both within words and
across words. The results show that this place-assimilation process is highly
variable, both within and across speakers, and is also sensitive to factors such as the
place of articulation of the following consonant, the presence of a word boundary
and, to some extent, speech rate. Gestures affected by the process are generally
reduced categorically (deleted), while sporadic gradient reduction of gestures is
also observed. We further compare the results for coronals to our previous findings
on the assimilation of labials, discussing implications of the results for grammatical
models of phonological/phonetic competence. The results suggest that speakers’
language-particular knowledge of place assimilation has to be relatively
detailed and context-sensitive, and has to encode systematic regularities about its
obligatory/variable application as well as categorical/gradient realisation
Assessment of the in vitro antithrombotic properties of sardine (sardina pilchardus) fillet lipids and cod liver oil
peer-reviewedThe aim of the current study was to compare the biological activities of total polar
lipids (TPL) and thin-layer chromatography (TLC) polar lipid fractions of sardine fillet and
cod liver oil against atherogenesis. TPL and TLC polar lipid fractions obtained from these
two sources were assessed for their ability to inhibit the platelet-activating-factor
(PAF)-induced platelet aggregation (PAF-antagonists) or to induce platelet aggregation
(PAF-agonists), since PAF plays a crucial role in the initiation and development of
atherosclerosis. This study focused on the polar lipids since previous studies have underlined
that the antithrombotic properties of foodstuffs are mainly attributed to polar lipid
micro-constituents. TPL of sardine fillet induced platelet aggregation, while TPL of cod
liver had a bimodal effect on platelets. TLC polar lipid fractions of both samples exhibited
in vitro aggregatory and inhibitory activity towards platelets. However, TLC sardine polar
lipid fractions showed stronger in vitro antithrombotic activities than the cod liver oil ones.
These data constitute evidence of the putative contribution of fish polar lipids against cardiovascular diseases, underling firstly the beneficial effect of fish and fish lipids as
functional foodstuffs against atherogenesis and secondly the more important role of sardine
polar lipids as opposed to cod liver oil.PUBLISHEDpeer-reviewe
Temperature-scaling behavior of the Hall conductivity for Hg-based superconducting thin films
The Hall conductivities of HgBa_{2}CaCu_{2}O_{6+\delta}and
HgBa_{2}Ca_{2}Cu_{3}O_{8+\delta} thin films are investigated for a magnetic
field parallel to the c axis. The mixed-state Hall conductivity for these
compounds is well described by \sigma_{xy}=C_{1}/H+C_{2}+C_{3}H. The prefactor
C_1 shows a temperature dependence of the form C_1 = A(1-t)^n near T_c, where
t=T/T_c is the reduced temperature. Contrary to the previous results, C_2 also
follows a temperature-scaling behavior similar to that of the coefficient C_1.
The observed value of n = 1.8 - 2.3 is comparable to the previously observed
values for YBa_{2}Cu_{3}O_{7-\delta} and La_{2-x}Sr_{x}CuO_{4}.Comment: 5 pages, 4 eps figure
Simultaneous amplification and screening of whole plasmids using the T7 bacteriophage replisome
This study describes a novel helicase-mediated isothermal DNA amplification method that exponentially amplifies circular DNAs. The circular helicase-dependent amplification (cHDA) system is based on the T7 replication machinery, which includes the processive T7 helicase, an exonuclease-deficient T7 DNA polymerase (T7 Sequenase) and the T7 Gp2.5 single-stranded DNA-binding (SSB) protein. After the duplex DNA template is unwound by the T7 helicase, specific primers anneal to the separated DNA strands and T7 Sequenase extends the 3′ end of each primer by a rolling circle mechanism to amplify not only a region defined by the primers but also continuous concatemers of the template. The cHDA reaction can be carried out at one temperature (25°C) for the entire process and can achieve up to 10 000-fold amplification. Amplification can be performed using purified plasmid DNA or a crude cell lysate and can amplify inserts as large as 10 kb. Following a cHDA reaction, the amplified products can be used directly for sequencing and restriction enzyme digestion without further purification. By utilizing the helicase enzyme, circular DNA samples can be simultaneously screened and amplified at one constant temperature in one easy step
Thermally activated charge carriers and mid-infrared optical excitations in quarter-filled CDW systems
The optical properties of the quarter-filled single-band CDW systems have
been reexamined in the model with the electron-phonon coupling related to the
variations of electron site energies. It appears that the indirect,
electron-mediated coupling between phase phonons and external electromagnetic
fields vanishes for symmetry reasons, at variance with the infrared selection
rules used in the generally accepted microscopic theory. It is shown that the
phase phonon modes and the electric fields couple directly, with the coupling
constant proportional to the magnitude of the charge-density wave. The
single-particle contributions to the optical conductivity tensor are determined
for the ordered CDW state and the related weakly doped metallic state by means
of the Bethe--Salpeter equations for elementary electron-hole excitations. It
turns out that this gauge-invariant approach establishes a clear connection
between the effective numbers of residual, thermally activated and bound charge
carriers. Finally, the relation between these numbers and the activation energy
of dc conductivity and the optical CDW gap scale is explained in the way
consistent with the conductivity sum rules.Comment: 12 pages, 9 figure
Truncation of a 2-dimensional Fermi surface due to quasiparticle gap formation at the saddle points
We study a two-dimensional Fermi liquid with a Fermi surface containing the
saddle points and . Including Cooper and Peierls channel
contributions leads to a one-loop renormalization group flow to strong coupling
for short range repulsive interactions. In a certain parameter range the
characteristics of the fixed point, opening of a spin and charge gap and
dominant pairing correlations are similar to those of a 2-leg ladder at
half-filling. An increase of the electron density we argue leads to a
truncation of the Fermi surface with only 4 disconnected arcs remaining.Comment: Reference added. RevTeX 4 pages incl. 4 ps file
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