427 research outputs found
Encapsulación de compuestos biocidas en materiales siliceos mesoporosos
Se llevó a cabo la síntesis de materiales silíceos mesoporosos con diferentes grados de ordenamiento (SBA-15, MCF). Se estudió su uso como matrices estabilizadoras de un biocida comercial. Mediante adsorción/desorción de N2 y FTIR se determinó la variación del volumen de poros y superficie específica de las matrices silíceas ocasionada por la adsorción del biocida y la no alteración
estructural del mismo cuando se encuentra adsorbido. La actividad antifúngica frente a Aspergillus Niger fue evaluada mediante la determinación de la concentración mínima inhibitoria. Los materiales tipo MCF incorporan un mayor porcentaje de adsorbato, mientras que el biocida incorporado en las sílices ordenadas SBA-15 posee mejor comportamiento antifúngicoFil: Basaldella, Elena Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas "dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Cs.exactas. Centro de Investigación y Desarrollo En Ciencias Aplicadas ; Argentina. Universidad Tecnológica Nacional. Facultad Regional La Plata. Centro de Investigación y Desarrollo en Ciencia y Tecnología de Materiales; ArgentinaFil: Mardones, Lucas E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas "dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Cs.exactas. Centro de Investigación y Desarrollo En Ciencias Aplicadas ; Argentina. Universidad Tecnológica Nacional. Facultad Regional La Plata. Centro de Investigación y Desarrollo en Ciencia y Tecnología de Materiales; ArgentinaFil: Legnoverde, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Investigación y Desarrollo En Ciencias Aplicadas "dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Cs.exactas. Centro de Investigación y Desarrollo En Ciencias Aplicadas ; Argentina. Universidad Tecnológica Nacional. Facultad Regional La Plata. Centro de Investigación y Desarrollo en Ciencia y Tecnología de Materiales; Argentin
Reinventando el Self. Potencia y contradicción en comunidades intencionales ecológicas
We are currently witnessing a social and ecological crisis that requires immediate solutions, but at the same time imposes contradictions at different levels. We observed the emergence of intentional communities that experience other forms of relationship between the common, nature and the individual. Our research is framed within these communities and its objective was to analyze the practices in which Self is constituted. Through an ethnographic approach we investigated three case studies located in Chile, where we conducted participatory observations and in-depth interviews. Our results show that the constitution of the subject emerges in the practices as a transitory Self from the spiritual, religious, planetary, communitarian and individual agency. We conclude that the subject emerges as an expanded Self, narratively contradictory, communally affective, and socially withdrawn, contradictorily constituted between individual freedom, communal creativity and the constrictions of capital.En la actualidad constatamos una crisis social y ecológica que requiere soluciones inmediatas, pero que al mismo tiempo impone contradicciones en diferentes niveles. En este contexto, evidenciamos el surgimiento de comunidades intencionales que experimentan otras formas de relación entre lo común, la naturaleza y el individuo. Es en estos espacios donde situamos nuestra investigación, que tuvo como objetivo analizar las prácticas en las que emerge el Self. A través de un enfoque etnográfico investigamos tres estudios de caso ubicados en Chile, donde realizamos observaciones participativas y entrevistas en profundidad. Nuestros resultados muestran que la constitución del sujeto emerge en las prácticas como un Self transitorio desde la agencia espiritual, religiosa, planetaria, comunitaria e individual. Concluimos que el sujeto emerge como un Self expandido, narrativamente contradictorio, comunitariamente afectivo y socialmente retraído, que se actualiza contradictoriamente entre la libertad individual, la creatividad comunitaria y las constricciones del capital
A Multiwavelength Study of Young Massive Star-Forming Regions. III. Mid-Infrared Emission
We present mid-infrared (MIR) observations, made with the TIMMI2 camera on
the ESO 3.6 m telescope, toward 14 young massive star-forming regions. All
regions were imaged in the N band, and nine in the Q band, with an angular
resolution of ~ 1 arcsec. Typically, the regions exhibit a single or two
compact sources (with sizes in the range 0.008-0.18 pc) plus extended diffuse
emission. The Spitzer-Galactic Legacy Infrared Mid-Plane Survey Extraordinaire
images of these regions show much more extended emission than that seen by
TIMMI2, and this is attributed to polycyclic aromatic hydrocarbon (PAH) bands.
For the MIR sources associated with radio continuum radiation (Paper I) there
is a close morphological correspondence between the two emissions, suggesting
that the ionized gas (radio source) and hot dust (MIR source) coexist inside
the H II region. We found five MIR compact sources which are not associated
with radio continuum emission, and are thus prime candidates for hosting young
massive protostars. In particular, objects IRAS 14593-5852 II (only detected at
17.7 microns) and 17008-4040 I are likely to be genuine O-type protostellar
objects. We also present TIMMI2 N-band spectra of eight sources, all of which
are dominated by a prominent silicate absorption feature (~ 9.7 microns). From
these data we estimate column densities in the range (7-17)x10^22 cm^-2, in
good agreement with those derived from the 1.2 mm data (Paper II). Seven
sources show bright [Ne II] line emission, as expected from ionized gas
regions. Only IRAS 123830-6128 shows detectable PAH emission at 8.6 and 11.3
microns.Comment: Published in ApJ. 15 pages, 6 figures. Formatted with emulateapj; v2:
Minor language changes to match the published versio
Dynamics of a Massive Binary at Birth
Almost all massive stars have bound stellar companions, existing in binaries
or higher-order multiples. While binarity is theorized to be an essential
feature of how massive stars form, essentially all information about such
properties is derived from observations of already formed stars, whose orbital
properties may have evolved since birth. Little is known about binarity during
formation stages. Here we report high angular resolution observations of 1.3 mm
continuum and H30alpha recombination line emission, which reveal a massive
protobinary with apparent separation of 180 au at the center of the massive
star-forming region IRAS07299-1651. From the line-of-sight velocity difference
of 9.5 km/s of the two protostars, the binary is estimated to have a minimum
total mass of 18 solar masses, consistent with several other metrics, and
maximum period of 570 years, assuming a circular orbit. The H30alpha line from
the primary protostar shows kinematics consistent with rotation along a ring of
radius of 12 au. The observations indicate that disk fragmentation at several
hundred au may have formed the binary, and much smaller disks are feeding the
individual protostars.Comment: Published in Nature Astronomy. This is author's version. Full article
is available here (https://rdcu.be/brENk). 47 pages, 10 figures, including
methods and supplementary informatio
β-decay rates of 121–131Cs in the microscopic interacting boson-fermion model
β
-decay rates of
121–131
Cs have been calculated in the framework of the neutron-proton interacting boson-
fermion model (IBFM-2). For odd-
A
nuclei, the decay operator can be written in a relatively simple form in terms
of the one-nucleon transfer operator. Previous studies of
β
decay in IBFM-2 were based on a transfer operator
obtained by using the number operator approximation (NOA). In this work a new form of the one-nucleon transfer
operator, derived microscopically without the NOA approximation, is used. The results from both approaches are
compared and show that the deviation from experimental data is reduced without using the NOA approximation.
Indications about the renormalization of the Fermi and Gamow-Teller matrix elements are discussed. This is
a further step toward a more complete description of low-lying states in medium and heavy nuclei which is
necessary to compute reliable matrix elements in studies of current active interest such as double-
β
decay or
neutrino absorption experimentsMinisterio de Economía y Competitividad (España) FIS2014-53448-C2-1-PConsejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía FQM-160 P11-FQM-763
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