3,388 research outputs found
Alkaline battery containing a separator of a cross-linked copolymer of vinyl alcohol and unsaturated carboxylic acid
A battery separator for an alkaline battery is described. The separator comprises a cross linked copolymer of vinyl alcohol units and unsaturated carboxylic acid units. The cross linked copolymer is insoluble in water, has excellent zincate diffusion and oxygen gas barrier properties and a low electrical resistivity. Cross linking with a polyaldehyde cross linking agent is preferred
Photofission of heavy nuclei at energies up to 4 GeV
Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and
natPb have been measured simultaneously, using tagged photons in the energy
range Egamma=0.17-3.84 GeV. This was the first experiment performed using the
Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the
photofission cross section for 238U relative to that for 237Np is about 80%,
implying the presence of important processes that compete with fission. We also
observe that the relative photofission cross sections do not depend strongly on
the incident photon energy over this entire energy range. If we assume that for
237Np the photofission probability is equal to unity, we observe a significant
shadowing effect starting below 1.5 GeV.Comment: 4 pages of RevTex, 6 postscript figures, Submitted to Phys. Rev. Let
Tiras de Amitraz contra el ácaro Varroa jacobsoni Oudemans en colmenas de Apis mellifera L.
Cuban plastic strips containing 13,2 mg Amitraz (amidine) -commercially patented as Apizel- were evaluated in their effectiveness against Varroa jacobsoni Oudemans acarus in Apis mellifera beehives. These strips were compared to French ones, commercially named Apivar, which contain 500 mg of an active substance from the manufacturer's instructions, 8 Apizel (Apiary A) strips (105,6 mg) were applied to double beehives and 4 strips (52,8 mg) to single beehives. As indicated, two Apivar (Apiary B) strips were randomly placed in each hive (1000 mg). The 8 beehives from Apiary A showed an initial infectation general rate of 12,86%; but after six weeks of treatment, this value decreased to 2,90% (77,45% decrease), while Apiary B initial infectation general rate of 2,41% was only reduced to 0,11% (95,43% decrease) during the same time. It is evident that, although initial rates are highly different, French strips effectiveness can be evaluated as good, but Cuban strips did not achieve an acceptable effect due to a lower dosage of the active substance used.Para combatir el ácaro Varroa jacobsoni Oudemans en colmenas de Apis mellifera, se evaluaron tiras plásticas cubanas contentivas de 13,2 mg de Amitraz (amidina), bajo el nombre comercial de Apizel. Las mismas se compararon con tiras francesas cuyo nombre comercial es Apivar, que contenían 500 mg de sustancia activa del mismo compuesto químico. Siguiendo las instrucciones del fabricante, el Apizel (apiario A) se aplicó a razón de 8 tiras (105,6 mg) para colmenas de dos cuerpos y 4 tiras (52,8 mg) para aquellas que tenían un cuerpo. Como está indicado, del Apivar (apiario B) se colocaron dos tiras por colmena (1 000 mg), indistintamente. Las 8 colmenas del apiario A, presentaron una tasa general de infestación inicial de 12,86% y a las 6 semanas de tratamiento había descendido a 2,90 % (77,45 % de disminución), en tanto el apiario B, con tasa inicial de 2,41 %, en igual lapso de tiempo descendió a 0,11 % (95,43 % de descenso). Es evidente que a pesar de existir tasas iniciales muy diferentes, las tiras francesas tuvieron una efectividad que se puede considerar buena, en tanto estas tiras cubanas no alcanzaron un nivel aceptable, con toda seguridad a causa de la subdosificación de la sustancia activa
Simulation of the CMS Resistive Plate Chambers
The Resistive Plate Chamber (RPC) muon subsystem contributes significantly to
the formation of the trigger decision and reconstruction of the muon trajectory
parameters. Simulation of the RPC response is a crucial part of the entire CMS
Monte Carlo software and directly influences the final physical results. An
algorithm based on the parametrization of RPC efficiency, noise, cluster size
and timing for every strip has been developed. Experimental data obtained from
cosmic and proton-proton collisions at TeV have been used for
determination of the parameters. A dedicated validation procedure has been
developed. A good agreement between the simulated and experimental data has
been achieved.Comment: to be published in JINS
The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective
With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits -all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy. (C) 2020 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.Peer reviewe
Exact Solution for the Exterior Field of a Rotating Neutron Star
A four-parameter class of exact asymptotically flat solutions of the
Einstein-Maxwell equations involving only rational functions is presented. It
is able to describe the exterior field of a slowly or rapidly rotating neutron
star with poloidal magnetic field.Comment: Accepted for publication in Phys. Rev. D as Rapid Communication. 8
pages, 2 eps figure
Evaluation of the total photoabsorption cross sections for actinides from photofission data and model calculations
We have calculated the fission probabilities for 237-Np, 233,235,238-U,
232-Th, and nat-Pb following the absorption of photons with energies from 68
MeV to 3.77 GeV using the RELDIS Monte-Carlo code. This code implements the
cascade-evaporation-fission model of intermediate-energy photonuclear
reactions. It includes multiparticle production in photoreactions on
intranuclear nucleons, pre-equilibrium emission, and the statistical decay of
excited residual nuclei via competition of evaporation, fission, and
multifragmentation processes. The calculations show that in the GeV energy
region the fission process is not solely responsible for the entire total
photoabsorption cross section, even for the actinides: ~55-70% for 232-Th,
\~70-80% for 238-U, and ~80-95% for 233-U, 235-U, and 237-Np. This is because
certain residual nuclei that are created by deep photospallation at GeV photon
energies have relatively low fission probabilities. Using the recent
experimental data on photofission cross sections for 237-Np and 233,235,238-U
from the Saskatchewan and Jefferson Laboratories and our calculated fission
probabilities, we infer the total photoabsorption cross sections for these four
nuclei. The resulting cross sections per nucleon agree in shape and in
magnitude with each other. However, disagreement in magnitude with
total-photoabsorption cross-section data from previous measurements for nuclei
from C to Pb calls into question the concept of a ``Universal Curve'' for the
photoabsorption cross section per nucleon for all nuclei.Comment: 39 pages including 11 figure
High rate, fast timing Glass RPC for the high {\eta} CMS muon detectors
The HL-LHC phase is designed to increase by an order of magnitude the amount
of data to be collected by the LHC experiments. To achieve this goal in a
reasonable time scale the instantaneous luminosity would also increase by an
order of magnitude up to . The region of the forward
muon spectrometer () is not equipped with RPC stations. The
increase of the expected particles rate up to (including a
safety factor 3) motivates the installation of RPC chambers to guarantee
redundancy with the CSC chambers already present. The actual RPC technology of
CMS cannot sustain the expected background level. The new technology that will
be chosen should have a high rate capability and provides a good spatial and
timing resolution. A new generation of Glass-RPC (GRPC) using low-resistivity
(LR) glass is proposed to equip at least the two most far away of the four high
muon stations of CMS. First the design of small size prototypes and
studies of their performance in high-rate particles flux is presented. Then the
proposed designs for large size chambers and their fast-timing electronic
readout are examined and preliminary results are provided.Comment: 14 pages, 11 figures, Conference proceeding for the 2016 Resistive
Plate Chambers and Related Detector
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