6,291 research outputs found
Quantification and characterization of water and wastewater in dairy farms II. Effluent quality and treatment process efficiency
This study was carried out in three dairy production areas in Buenos Aires. Effluent quality,
treatment process efficiency, water management strategies and environmental contamination risk by
effluent discharge, was characterized in 9 dairy farms. Holding area feces were measured. Treatment
lagoons were sampled. Physicochemical and microbiological qualities, and BOD and COD were
determined, and used as environmental risk indicators. Plate-cooler water management strategies
were established in order to divide the dairy farms in two groups (G1 and G2). Treatment lagoons
were inefficient in regards to effluent treatment. BOD, COD, nitrogen (N), phosphorus (P) and
enterococci found in the samples were not within acceptable values according to effluent discharge
guidelines. NPK concentration would allow its potential use as a nutrient source. Variability found in
the several parameters measured is related to the different lagoons? characteristics and water
management strategies. Significant differences (p<0.05) were detected in N and P contents between
G1 and G2. Proper environmental management in animal production systems requires an appropriate
wastewater handling within each farm.Fil: Nosetti, L. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Buenos Aires, ArgentinaFil: Herrero, M.A. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Producción Animal. Buenos Aires, ArgentinaFil: Pol, M. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Producción Animal. Buenos Aires, ArgentinaFil: Maldonado May, V. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Producción Animal. Buenos Aires, ArgentinaFil: Korol, S. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Higiene y Sanidad. Buenos Aires, ArgentinaFil: Rossi, S. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Higiene y Sanidad. Buenos Aires, ArgentinaFil: Gemini, V. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Cátedra de Higiene y Sanidad. Buenos Aires, ArgentinaFil: Flores, M. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Salud Pública. Buenos Aires, ArgentinaEl estudio fue realizado en tres cuencas lecheras de Buenos Aires. Se caracterizaron en 9
establecimientos, la calidad de efluentes, la eficiencia de los sistemas de tratamiento, la estrategia del
manejo del agua en el ordeño y el riesgo de contaminación ambiental por el vertido de efluentes.
Fueron cuantificadas las heces en corrales de espera. Se tomaron muestras de las lagunas de tratamiento,
analizando la calidad fisicoquímica y microbiológica. La DBO y DQO fueron utilizados como
indicadores de riesgo ambiental. Los tambos fueron agrupados según la utilización del agua de la
placa de refrescado (G1 y G2). Las lagunas no resultaron eficientes ya que no completaron el tratamiento
de los efluentes, tampoco se obtuvieron valores aceptables de DQO, DBO, Nitrógeno (N), Fósforo
(P) y enterococos, compatibles con normativas de vertido para evitar la contaminación de cursos de
agua. La concentración de NPK permitiría su uso potencial como abono. La variabilidad de los
parámetros analizados se relaciona a las diferentes características de las lagunas y a los sistemas de
reutilización de agua. Se encontraron diferencias significativas (p<0.05), entre G1 y G2, para el
contenido de nitrógeno y fósforo. Las necesidades de una gestión ambiental adecuada en los sistemas
de producción animal, requiere de un manejo apropiado de estos residuos dentro del mismo
establecimiento
Detectability of non-differentiable generalized synchrony
Generalized synchronization of chaos is a type of cooperative behavior in
directionally-coupled oscillators that is characterized by existence of stable
and persistent functional dependence of response trajectories from the chaotic
trajectory of driving oscillator. In many practical cases this function is
non-differentiable and has a very complex shape. The generalized synchrony in
such cases seems to be undetectable, and only the cases, in which a
differentiable synchronization function exists, are considered to make sense in
practice. We show that this viewpoint is not always correct and the
non-differentiable generalized synchrony can be revealed in many practical
cases. Conditions for detection of generalized synchrony are derived
analytically, and illustrated numerically with a simple example of
non-differentiable generalized synchronization.Comment: 8 pages, 8 figures, submitted to PR
Phase-Induced (In)-Stability in Coupled Parametric Oscillators
We report results on a model of two coupled oscillators that undergo periodic
parametric modulations with a phase difference . Being to a large
extent analytically solvable, the model reveals a rich dependence of
the regions of parametric resonance. In particular, the intuitive notion that
anti-phase modulations are less prone to parametric resonance is confirmed for
sufficiently large coupling and damping. We also compare our results to a
recently reported mean field model of collective parametric instability,
showing that the two-oscillator model can capture much of the qualitative
behavior of the infinite system.Comment: 19 pages, 8 figures; a version with better quality figures can be
found in http://hypatia.ucsd.edu/~mauro/English/publications.htm
Impaired Cerebellar Functional Connectivity in Schizophrenia Patients and Their Healthy Siblings
The long-standing notion of schizophrenia as a disorder of connectivity is supported by emerging evidence from recent neuroimaging studies, suggesting impairments of both structural and functional connectivity in schizophrenia. However, investigations are generally restricted to supratentorial brain regions, thereby excluding the cerebellum. As increasing evidence suggests that the cerebellum contributes to cognitive and affective processing, aberrant connectivity in schizophrenia may include cerebellar dysconnectivity. Moreover, as schizophrenia is highly heritable, unaffected family members of schizophrenia patients may exhibit similar connectivity profiles. The present study applies resting-state functional magnetic resonance imaging to determine cerebellar functional connectivity profiles, and the familial component of cerebellar connectivity profiles, in 62 schizophrenia patients and 67 siblings of schizophrenia patients. Compared to healthy control subjects, schizophrenia patients showed impaired functional connectivity between the cerebellum and several left-sided cerebral regions, including the hippocampus, thalamus, middle cingulate gyrus, triangular part of the inferior frontal gyrus, supplementary motor area, and lingual gyrus (all p < 0.0025, whole-brain significant). Importantly, siblings of schizophrenia patients showed several similarities to patients in cerebellar functional connectivity, suggesting that cerebellar dysconnectivity in schizophrenia might be related to familial factors. In conclusion, our findings suggest that dysconnectivity in schizophrenia involves the cerebellum and that this defect may be related to the risk to develop the illness
LIQUISOLID COMPACTS: A PROMISING APPROACH FOR SOLUBILITY ENHANCEMENT
At present 40% of the drugs within the development pipelines, and approximately 60 % of the drugs coming directly from synthesis area unit poorly soluble. Â Solubility is one of the important parameter to obtain desired concentration of drug in systemic circulation. Liquisolid compacts technique is a new and promising approach to overcome this consequence and that can change the dissolution rate of water insoluble drugs and increase the bioavailability of the drugs. This technique is an efficient method for formulating water insoluble and water soluble drugs. This technique relies upon the admixture of drug loaded solutions with applicable carrier and coating materials. Liquisolid system is characterized by flow behaviour, wettability, powder bed hydrophilicity, saturation solubility, drug content, differential scanning calorimetry, Fourier transform infra-red spectroscopy, powder X-ray diffraction, scanning electron microscopy, in-vitro release and in-vivo evaluation. This review article explains the preparation, classification and application of liquisolid system. Key word: Liquisolid system, water insoluble drug, carrier material, coating materialÂ
Boosting the Figure Of Merit of LSPR-based refractive index sensing by phase-sensitive measurements
Localized surface plasmon resonances possess very interesting properties for
a wide variety of sensing applications. In many of the existing applications
only the intensity of the reflected or transmitted signals is taken into
account, while the phase information is ignored. At the center frequency of a
(localized) surface plasmon resonance, the electron cloud makes the transition
between in- and out-of-phase oscillation with respect to the incident wave.
Here we show that this information can experimentally be extracted by
performing phase-sensitive measurements, which result in linewidths that are
almost one order of magnitude smaller than those for intensity based
measurements. As this phase transition is an intrinsic property of a plasmon
resonance, this opens up many possibilities for boosting the figure of merit
(FOM) of refractive index sensing by taking into account the phase of the
plasmon resonance. We experimentally investigated this for two model systems:
randomly distributed gold nanodisks and gold nanorings on top of a continuous
gold layer and a dielectric spacer and observed FOM values up to 8.3 and 16.5
for the respective nanoparticles
- …