1,257 research outputs found
Chromium recovery by membranes for process reuse in the tannery industry
Leather tanning is a wide common industry all over the
world. In leather processing, water is one of the most
important medium, almost 40-45 L water kg-1 raw-hide or
skin is used by tanneries for processing finished leathers.
The composition of tannery wastewater presents
considerable dissimilarities in the concentration range of
pollutants both of inorganic (chlorides, with concentration
ranging from several hundred to over 10,000 mg L-1 Cl–;
sulphate (VI), ammonium ions and sulphide ions,
exhibiting concentration that ranges from tens to several
hundred mg L-1) and organic (the COD value is usually
several thousand mg L-1 O2). Throughout the years, many
conventional processes have been carried out to treat
wastewater from tannery industry: unfortunately, in this
case, biological treatment methods give rise to an
excessive production of sludge, whereas physical and
chemical methods are too expensive in terms of energy and
reagent costs. In this work, a membrane process based on
NF membrane modules was adopted to treat the tannery
feedstock after primary conventional treatment. In a first
step, the determination of all boundary flux parameters, in
order to inhibit severe fouling formation during operation,
were performed. After this, experimental work was carried
out to validate the approach. The target of water
purification was reached, that is the legal discharge to
municipal sewer system in Italy of 90% of the initial
wastewater stream volume. This allows having an
immediate cost saving of 21%. Moreover, the developed
process leads to a second benefit, that is the production of
5% of the initial volume as a highly chromium-rich
concentrate at no cost suitable to tannery process recycle
and reuse. In this case, cost saving rates exceeds 40%. At
the end, scale-up of the investigated process will be
discussed from technical and economic point of view
Forgotten exogenous corticosteroid as a cause of central serous chorioretinopathy
Central serous chorioretinopathy (CSCR) is an idiopathic ocular condition – first described in 1866 – that is well known to ophthalmologists. It is less well known to other practitioners. Glucocorticoids have been strongly implicated as a pathogenic factor. We report three patients who developed CSCR following exogenous administration of corticosteroid. Because our patients did not suspect the use of corticosteroid to be important or causative, they did not volunteer the historical detail, and admitted to exogenous corticosteroid injection only with intensive questioning. For their part, physicians should be cognizant of the risk of corticosteroid-induced CSCR, particularly in patients with a prior history of the potentially sight-threatening disease. The development of CSCR is an important iatrogenic and often unrecognized side effect of exogenously administered corticosteroid
Active galactic nuclei synapses: X-ray versus optical classifications using artificial neural networks
(Abridged) Many classes of active galactic nuclei (AGN) have been defined
entirely throughout optical wavelengths while the X-ray spectra have been very
useful to investigate their inner regions. However, optical and X-ray results
show many discrepancies that have not been fully understood yet. The aim of
this paper is to study the "synapses" between the X-ray and optical
classifications.
For the first time, the new EFLUXER task allowed us to analyse broad band
X-ray spectra of emission line nuclei (ELN) without any prior spectral fitting
using artificial neural networks (ANNs). Our sample comprises 162 XMM-Newton/pn
spectra of 90 local ELN in the Palomar sample. It includes starbursts (SB),
transition objects (T2), LINERs (L1.8 and L2), and Seyferts (S1, S1.8, and S2).
The ANNs are 90% efficient at classifying the trained classes S1, S1.8, and
SB. The S1 and S1.8 classes show a wide range of S1- and S1.8-like components.
We suggest that this is related to a large degree of obscuration at X-rays. The
S1, S1.8, S2, L1.8, L2/T2/SB-AGN (SB with indications of AGN), and SB classes
have similar average X-ray spectra within each class, but these average spectra
can be distinguished from class to class. The S2 (L1.8) class is linked to the
S1.8 (S1) class with larger SB-like component than the S1.8 (S1) class. The L2,
T2, and SB-AGN classes conform a class in the X-rays similar to the S2 class
albeit with larger fractions of SB-like component. This SB-like component is
the contribution of the star-formation in the host galaxy, which is large when
the AGN is weak. An AGN-like component seems to be present in the vast majority
of the ELN, attending to the non-negligible fraction of S1-like or S1.8-like
component. This trained ANN could be used to infer optical properties from
X-ray spectra in surveys like eRosita.Comment: 15 pages, 7 figures, accepted for publication in A&A. Appendix B only
in the full version of the paper here:
https://dl.dropboxusercontent.com/u/3484086/AGNSynapsis_OGM_online.pd
Short-Term Effect of Daily Herbage Allowance Restriction on Pasture Condition and the Performance of Grazing Dairy Cows during Autumn
The aim of this study was to evaluate the short-term effects of daily herbage allowance (DHA, defined as the product of pre-grazing herbage mass and offered area per animal) on pasture conditions and milk production of Holstein-Friesian dairy cows. Forty-four early lactation dairy cows were randomly assigned to one of four treatments in a 2 × 2 factorial design that tested two levels of DHA (17 and 25 kg DM/cow.day) and two levels of maize silage supplementation (MSS, 4.5 and 9 kg DM/cow.day) over a 77-day period. Low DHA decreased the post-grazing herbage mass from 1546 to 1430 kg DM/ha and the compressed sward height from 5 to 4.4 cm, while the grazing efficiency remained unaffected. Low DHA induced a faster herbage mass reduction, while the sward-height and pasture characteristics did not differ from the high DHA regime. Low DHA decreased the tiller production rates and daily lamina growth, while the leaf-production rate was not affected by the DHA. Daily increases of herbage mass were greater in the high DHA than in the low DHA treatments.
Individual milk production and milk protein concentration decreased at a low DHA compared to high DHA, while the milk fat concentration was greater and the milk output per hectare increased by 1510 kg. Neither the MSS level nor the interaction DHA by the MSS level had any effect on the sward characteristics or the productivity of the cows. From these results, it is suggested that,in a high-quality pasture, using 17 kg DM/cow.day was appropriate for improving both herbage utilization and milk production per hectare while maintaining the short-term conditions of a pasture grazed by dairy cows in the autumn
El populismo punitivo de los medios de comunicaci?n frente a la detenci?n preventiva del procesado en Colombia
62 p. Recurso Electr?nicoEn el presente art?culo de reflexi?n, se abordar? el tema del endurecimiento de las leyes hacia el sujeto procesal en el sistema penal punitivo, sobre la base del aumento de las penas y nuevas conductas delictivas, lo que se ha venido denominando como populismo punitivo; dicho fen?meno se encuentra apoyado por juicios sentenciadores dados por los medios masivos de comunicaci?n, quienes legitiman soluciones medi?ticas a los problemas sociales existentes y cuya pretensi?n es sosegar el clamor por la seguridad que exige la poblaci?n, difundiendo los m?s escandalosos casos judiciales; situaci?n que ha creado una falsa expectativa de lo que es la justicia, afectando por medio de la detenci?n preventiva de la libertad, m?ltiples derechos fundamentales tales como el buen nombre, honra y presunci?n de inocencia del procesado, al caer en juzgamientos anticipados, sin la prevalencia de principios constitucionales, sociales y penales; garantes del sistema acusatorio y acogidos por un Estado Social y Democr?tico de Derecho.
Palabras Clave: libertad, poder, populismo punitivo, medios masivos de comunicaci?n, presunci?n de inocencia, honra, buen nombre.In the present article of reflection, will be approached the topic of the hardening of the laws towards the subject procedural in the punitive penal system, on the base of the increase of the penalties and new criminal conducts, which has been denominated like punitive populism; this phenomenon is supported by sentencing judgments given by the mass media, who legitimize media solutions to existing social problems whose aim is to calm the clamor for security demanded by the population, spreading the most scandalous court cases; a situation that has created a false expectation of what is justice, and affecting through the preventive detention of freedom, multiple fundamental rights such as the good name, honor and presumption of innocence of the defendant, to fall in anticipated judgments, without the prevalence of constitutional principles, social and criminal; guarantors of the accusatory system and welcomed by a Social and Democratic State of Law.
Keywords: freedom, power, punitive populism, mass media, presumption of innocence, honor, good name
Infrared and optical polarimetry around the low-mass star-forming region NGC 1333 IRAS 4A
We performed J- and R-band linear polarimetry with the 4.2 m William Herschel
Telescope at the Observatorio del Roque de los Muchachos and with the 1.6 m
telescope at the Observat\'orio do Pico dos Dias, respectively, to derive the
magnetic field geometry of the diffuse molecular cloud surrounding the embedded
protostellar system NGC 1333 IRAS 4A. We obtained interstellar polarization
data for about two dozen stars. The distribution of polarization position
angles has low dispersion and suggests the existence of an ordered magnetic
field component at physical scales larger than the protostar. Some of the
observed stars present intrinsic polarization and evidence of being young
stellar objects. The estimated mean orientation of the interstellar magnetic
field as derived from these data is almost perpendicular to the main direction
of the magnetic field associated with the dense molecular envelope around IRAS
4A. Since the distribution of the CO emission in NGC 1333 indicates that the
diffuse molecular gas has a multi-layered structure, we suggest that the
observed polarization position angles are caused by the superposed projection
along the line of sight of different magnetic field components.Comment: 37 pages, 9 figures, 5 tables, accepted for publication in A
An in vitro experimental investigation of oscillatory flow in the cerebral aqueduct
This in vitro study aims at clarifying the relation between the oscillatory flow of cerebrospinal fluid (CSF) in
the cerebral aqueduct, a narrow conduit connecting the third and fourth ventricles, and the corresponding
interventricular pressure difference. Dimensional analysis is used in designing an anatomically correct scaled
model of the aqueduct flow, with physical similarity maintained by adjusting the flow frequency and the
properties of the working fluid. The time-varying pressure difference across the aqueduct corresponding
to a given oscillatory flow rate is measured in parametric ranges covering the range of flow conditions
commonly encountered in healthy subjects. Parametric dependences are delineated for the time-averaged
pressure fluctuations and for the phase lag between the transaqueductal pressure difference and the flow
rate, both having clinical relevance. The results are validated through comparisons with predictions obtained
with a previously derived computational model. The parametric quantification in this study enables the
derivation of a simple formula for the relation between the transaqueductal pressure and the stroke volume.
This relationship can be useful in the quantification of transmantle pressure differences based on non-invasive
magnetic-resonance-velocimetry measurements of aqueduct flow for investigation of CSF-related disorders.National Institutes of Health/
National Institute of Neurological Diseases and Stroke through contract
# 1R01NS120343-0
The nuclear and extended mid-infrared emission of Seyfert galaxies
We present subarcsecond resolution mid-infrared (MIR) images obtained with
8-10 m-class ground-based telescopes of a complete volume-limited (DL<40 Mpc)
sample of 24 Seyfert galaxies selected from the Swift/BAT nine month catalog.
We use those MIR images to study the nuclear and circumnuclear emission of the
galaxies. Using different methods to classify the MIR morphologies on scales of
~400 pc, we find that the majority of the galaxies (75-83%) are extended or
possibly extended and 17-25% are point-like. This extended emission is compact
and it has low surface brightness compared with the nuclear emission, and it
represents, on average, ~30% of the total MIR emission of the galaxies in the
sample. We find that the galaxies whose circumnuclear MIR emission is dominated
by star formation show more extended emission (650+-700 pc) than AGN-dominated
systems (300+-100 pc). In general, the galaxies with point-like MIR
morphologies are face-on or moderately inclined (b/a~0.4-1.0), and we do not
find significant differences between the morphologies of Sy1 and Sy2. We used
the nuclear and circumnuclear fluxes to investigate their correlation with
different AGN and SF activity indicators. We find that the nuclear MIR emission
(the inner ~70 pc) is strongly correlated with the X-ray emission (the harder
the X-rays the better the correlation) and with the [O IV] lambda 25.89 micron
emission line, indicating that it is AGN-dominated. We find the same results,
although with more scatter, for the circumnuclear emission, which indicates
that the AGN dominates the MIR emission in the inner ~400 pc of the galaxies,
with some contribution from star formation.Comment: 27 pages, 12 figures, accepted by MNRA
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