1,630 research outputs found
Rapid analytical determination of glutaraldehyde concentrations
Technique utilizes the iodimetric procedure which adds unknown excess of bisulfite to glutaraldehyde /GA/ then titrates unreacted bisulfite with standard iodine isotope to determine GA concentrations. Technique may interest microscopists, food researchers, biochemical or medical laboratories, and drug manufacturers
Extending higher dimensional quasi-cocycles
Let G be a group admitting a non-elementary acylindrical action on a Gromov
hyperbolic space (for example, a non-elementary relatively hyperbolic group, or
the mapping class group of a closed hyperbolic surface, or Out(F_n) for n>1).
We prove that, in degree 3, the bounded cohomology of G with real coefficients
is infinite-dimensional. Our proof is based on an extension to higher degrees
of a recent result by Hull and Osin. Namely, we prove that, if H is a
hyperbolically embedded subgroup of G and V is any G-module, then any n-quasi
cocycle on H with values in V may be extended to G. Also, we show that our
extensions detect the geometry of the embedding of hyperbolically embedded
subgroups, in a suitable sense.Comment: Minor revisions. This version has been accepted for publication by
the Journal of Topolog
Neutron therapy of cancer
Reports relate applications of neutrons to the problem of cancer therapy. The biochemical and biophysical aspects of fast-neutron therapy, neutron-capture and neutron-conversion therapy with intermediate-range neutrons are presented. Also included is a computer program for neutron-gamma radiobiology
Large neutrino mixing and normal mass hierarchy: a discrete understanding
We discuss the possibility of flavor symmetries to explain the pattern of
charged lepton and neutrino masses and mixing angles. We emphasize what are the
obstacles for the generation of an almost maximal atmospheric mixing and what
are the minimal ingredients to obtain it. A model based on the discrete
symmetry is constructed, which leads to the dominant -block in
the neutrino mass matrix, thus predicting normal hierarchy. This symmetry makes
it possible to reproduce current data and predicts
and strongly suppressed neutrinoless
-decay. Moreover, it implies a relation between lepton and quark mixing
angles: . The Cabibbo mixing can
also be reproduced and . is
thus a candidate to describe all the basic features of Standard Model fermion
masses and mixing.Comment: 9 pages, revtex, 1 eps figure; clarifications and comments added in
sections III.A.1. and III.C.; typos corrected; several references adde
Monojet searches for momentum-dependent dark matter interactions
We consider minimal dark matter scenarios featuring momentum-dependent couplings of the dark sector to the Standard Model. We derive constraints from existing LHC searches in the monojet channel, estimate the future LHC sensitivity for an integrated luminosity of 300 fb−1, and compare with models exhibiting conventional momentum-independent interactions with the dark sector. In addition to being well motivated by (composite) pseudo-Goldstone dark matter scenarios, momentum-dependent couplings are interesting as they weaken direct detection constraints. For a specific dark matter mass, the LHC turns out to be sensitive to smaller signal cross-sections in the momentum-dependent case, by virtue of the harder jet transverse-momentum distribution
Mid-infrared intersubband absorption from p-Ge quantum wells grown on Si substrates
Mid-infrared intersubband absorption from p-Ge quantum wells with Si0.5Ge0.5 barriers grown on a Si substrate is demonstrated from 6 to 9 μm wavelength at room temperature and can be tuned by adjusting the quantum well thickness. Fourier transform infra-red transmission and photoluminescence measurements demonstrate clear absorption peaks corresponding to intersubband transitions among confined hole states. The work indicates an approach that will allow quantum well intersubband photodetectors to be realized on Si substrates in the important atmospheric transmission window of 8–13 μm
Mid-Infrared Intersubband Absorption from P-Ge Quantum Wells on Si
Mid-infrared intersubband absorption from p-Ge quantum wells with Si0.5Ge0.5 barriers grown on a Si substrate is demonstrated from 6 to 9 μm wavelength at room temperature and can be tuned by adjusting the quantum well thickness. Fourier transform infra-red spectroscopy measurements demonstrate clear absorption peaks corresponding to intersubband transitions among confined hole states. The work indicates an approach that will allow quantum well intersubband photodetectors to be realized on Si substrates in the important atmospheric transmission window of 8–13 μm
Estudio no destructivo del interior de piezas de valor histórico mediante gammagrafÃas
La tecnología de Tomografía de Hormigón Armado desarrollada por THASA ha sido aplicada al estudio de piezas ornamentales y otras de valor histórico con el objeto de examinar el interior de las mismas e investigar, en algunos casos, la existencia, configuración y condición de refuerzos metálicos y en otro caso, la existencia de huecos producidos por termitas en vigas de madera. En este trabajo se discuten detalles metodológicos y resultados alcanzados en los casos de las estatuas ubicadas en el coronamiento del Palacio de Tribunales en la Ciudad Autónoma de Buenos Aires, en dragones colgantes de las torres de la Basílica de Luján y en las vigas del techo de la Capilla Doméstica, construida en 1660 y declarada patrimonio de la humanidad por la UNESCO, ubicada en la manzana jesuítica en la Ciudad de Córdoba. El carácter pionero de la investigación de oquedades en madera realizada en este último caso hizo necesario la construcción de modelos de simulación que resultan de utilidad para otras aplicaciones similares
- …