79 research outputs found
The influence of the Earth's magnetosphere on the high-energy solar protons
In the Earth's polar regions the intensity of the solar protons with the energy above the critical energy of geomagnetic cutoff is the same as in the interplanetary space. The penumbra in the polar regions is small and the East-West effect is also small. However the geomagnetic cutoff rigidity R sub c in polar regions is difficult to calculate because it is not sufficient to include only the internal sources of the geomagnetic field. During the magneto-quiescent periods the real value of R sub c can be less by 0.1 GV than the calculated value because of the external sources. During the geomagnetic storms the real value of R sub c is still lower
Raman spectroscopy as a structural characterization tool for lithium iron phosphates
Lithium iron phosphate LiFePO4 (LFP) with olivine structure was proposed to be used as a positive electrode material for lithium batteries in 1997 [1]. Twenty one years later LFP-based cells are widely used in traction batteries (LFP is the dominating cathode material for electric buses batteries) and stationary energy storages systems for grid balancing and renewables. Maybe, partially due to such a fast transition from promising to industrial-scale-produced positive electrode material, LFP still needs in some basic researches. One of the most important in the times of fast production scaling-up and steady price per kW∙h decreasing is the structural characterization...
Ionization in the atmosphere, comparison between measurements and simulations
A survey of the data on measured particle fluxes and the rate of ionization
in the atmosphere is presented. Measurements as a function of altitude, time
and cut-off rigidity are compared with simulations of particle production from
cosmic rays. The simulations generally give a reasonable representation of the
data. However, some discrepancies are found. The solar modulation of the
particle fluxes is measured and found to be a factor 2.70.8 greater than
that observed for muons alone near sea level.Comment: Accepted for publication in Astrophysics and Space Science
Transactions. Typographical errors fixe
РЕАБІЛІТАЦІЯ ДІТЕЙ ІЗ ПРОЯВАМИ СИНДРОМУ ДИСПЛАЗІЇ СПОЛУЧНОЇТКАНИНИ
50 children in the age of from 12 till 17years are surveyed. All children have been divided into 3 groups. The first group included 22 children with an easy degree of weight of hypermobility of joints. The second group included 16 children with the moderate degree of hypermobility of joints. Into the third group have entered practically healthy 12 children who have made control group. Complexes of the exercises used in complex treatment of children with hypermobility of joints are in detail described. Efficiency of these complexes is established. They allow to strengthen support - motor apparatus impellent device and to prevent progressing hypermobility of joints.Обследовано 50 детей в возрасте от 12 до 17 лет. Все дети были разделены на 3 группы. В первую группу вошло 22 детей с легкой степенью тяжести гипермобильности суставов. Во вторую группу вошло 16 детей с умеренной степенью гипермобильности суставов. В третью группу вошло 12 практически здоровых детей, составивших контрольную группу. Подробно описаны комплексы упражнений, использованных в комплексном лечении детей с гипермобильностью суставов. Установлена эффективность этих комплексов. Они позволяют укрепить опорно - двигательный аппарат й предотвратить прогрессирование гипермобильности суставов.Обстежено 50 дітей у віці від 12 до 17 років. Усі діти були розділені на 3 групи. У першу групу ввійшло 22 дітей з легким ступенем ваги гіпермобільності суглобів. В другу групу ввійшло 16 дітей з помірним ступенем гіпермобільності суглобів. У третю групу ввійшло 12 практично здорових дітей, що склали контрольну групу. Докладно описані комплекси вправ, використаних у комплексному лікуванні дітей з гіпермобільністю суглобів. Встановлено ефективність цих комплексів. Вони дозволяють зміцнити опорно – руховий апарат і запобігти прогресуванню гіпермобільності суглобів
Analysis of atmospheric pressure and temperature effects on cosmic ray measurements
In this paper, we analyze atmospheric pressure and temperature effects on the records of the cosmic ray detector CARPET. This detector has monitored secondary cosmic ray intensity since 2006 at Complejo Astronómico El Leoncito (San Juan, Argentina, 31S, 69W, 2550m over sea level) where the geomagnetic rigidity cutoff, Rc, is ~9.8 GV. From the correlation between atmospheric pressure deviations and relative cosmic ray variations, we obtain a barometric coefficient of ?0.440.01 %/hPa. Once the data are corrected for atmospheric pressure, they are used to analyze temperature effects using four methods.
Three methods are based on the surface temperature and the temperature at the altitude of maximum production of secondary cosmic rays. The fourth method, the integral method, takes into account the temperature height profile between 14 and 111 km above Complejo Astronómico El Leoncito. The results obtained from these four methods are compared on different time scales from seasonal time variations to scales related to the solar activity cycle. Our conclusion is that the integral method leads to better results to remove the temperature effect of the cosmic ray intensity observed at ground level.Fil: De Mendonça, R. R. S.. National Institute for Space Research. Division of Space Geophysics; Brasil;Fil: Raulin, J. P.. Universidade Presbiteriana Mackenzie; Brasil;Fil: Echer, E.. National Institute for Space Research. Division of Space Geophysics; Brasil;Fil: Makhmutov, V. S.. Russian Academy of Sciences. Lebedev Physical Institute; Rusia;Fil: Fernandez, German Enzo Leonel. Consejo Nacional de Invest.cientif.y Tecnicas. Ctro Cientifico Tecnologico Conicet - San Juan. Complejo Astronomico
Analysis of cosmic ray variations observed by the CARPET in association with solar flares in 2011-2012
The CARPET cosmic ray detector was installed on April 2006 at CASLEO (Complejo Astronmico El Leoncito) at the Argentinean Andes (31.8S, 69.3W, 2550 m, Rc=9.65 GV). This instrument was developed within an international cooperation between the Lebedev Physical Institute RAS (LPI; Russia), the Centro de Radio Astronomia e Astrofsica Mackenzie (CRAAM; Brazil) and the Complejo Astronmico el Leoncito (CASLEO; Argentina). In this paper we present results of analysis of cosmic ray variations recorded by the CARPET during increased solar flare activity in 2011-2012. Available solar and interplanetary medium observational data obtained onboard GOES, FERMI, ISS, as well as cosmic ray measurements by ground-based neutron monitor network were also used in the present analysis.Fil: Makhmutov, V.. Lebedev Physical Institute; Rusia. Universidade Presbiteriana Mackenzie; BrasilFil: Raulin, J. P.. Universidade Presbiteriana Mackenzie; BrasilFil: De Mendonca, R. R. S.. National Institute for Space Research; BrasilFil: Bazilevskaya, G. A.. Lebedev Physical Institute; RusiaFil: Correia, E.. Universidade Presbiteriana Mackenzie; Brasil. National Institute for Space Research; BrasilFil: Kaufmann, Pierre. Universidade Presbiteriana Mackenzie; BrasilFil: Marun, Adolfo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Fernandez, German Enzo Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Echer, E.. National Institute for Space Research; Brasi
The Gnevyshev Gap Effect in Galactic Cosmic Rays
Abstract During the last three solar cycles and in a wide energy range of galactic cosmic rays both the modulation and the variability of the intensity demonstrate effects related to the Gnevyshev Gap (GG) -a substantial decrease once or twice during the maximum phase of each solar cycle of a parameter that generally varies in phase with the cycle. The GG-effect also manifests itself in the behaviour of both the strength of the average interplanetary magnetic field and the power of its fluctuating component. The energy dependence of the GGeffect in the modulation and in the variability of the cosmic ray intensity was found to be different. The start of the GG-effect in the cosmic ray modulation practically coincides with a change in the energy dependence of the cosmic ray modulation
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Results from the CERN pilot CLOUD experiment
During a 4-week run in October–November 2006, a pilot experiment was performed at the CERN Proton Synchrotron in preparation for the Cosmics Leaving OUtdoor Droplets (CLOUD) experiment, whose aim is to study the possible influence of cosmic rays on clouds. The purpose of the pilot experiment was firstly to carry out exploratory measurements of the effect of ionising particle radiation on aerosol formation from trace H2SO4 vapour and secondly to provide technical input for the CLOUD design. A total of 44 nucleation bursts were produced and recorded, with formation rates of particles above the 3 nm detection threshold of between 0.1 and 100 cm−3 s−1, and growth rates between 2 and 37 nm h−1. The corresponding H2SO4 concentrations were typically around 106 cm−3 or less. The experimentally-measured formation rates and H2SO4 concentrations are comparable to those found in the atmosphere, supporting the idea that sulphuric acid is involved in the nucleation of atmospheric aerosols. However, sulphuric acid alone is not able to explain the observed rapid growth rates, which suggests the presence of additional trace vapours in the aerosol chamber, whose identity is unknown. By analysing the charged fraction, a few of the aerosol bursts appear to have a contribution from ion-induced nucleation and ion-ion recombination to form neutral clusters. Some indications were also found for the accelerator beam timing and intensity to influence the aerosol particle formation rate at the highest experimental SO2 concentrations of 6 ppb, although none was found at lower concentrations. Overall, the exploratory measurements provide suggestive evidence for ion-induced nucleation or ion-ion recombination as sources of aerosol particles. However in order to quantify the conditions under which ion processes become significant, improvements are needed in controlling the experimental variables and in the reproducibility of the experiments. Finally, concerning technical aspects, the most important lessons for the CLOUD design include the stringent requirement of internal cleanliness of the aerosol chamber, as well as maintenance of extremely stable temperatures (variations below 0.1 _C)
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Experimental investigation of ion-ion recombination under atmospheric conditions
We present the results of laboratory measurements of the ion–ion recombination coefficient at different temperatures, relative humidities and concentrations of ozone and sulfur dioxide. The experiments were carried out using the Cosmics Leaving OUtdoor Droplets (CLOUD) chamber at CERN, the walls of which are made of conductive material, making it possible to measure small ions. We produced ions in the chamber using a 3.5 GeV c−1 beam of positively charged pions (π+) generated by the CERN Proton Synchrotron (PS). When the PS was switched off, galactic cosmic rays were the only ionization source in the chamber. The range of the ion production rate varied from 2 to 100 cm−3 s−1, covering the typical range of ionization throughout the troposphere. The temperature ranged from −55 to 20 °C, the relative humidity (RH) from 0 to 70 %, the SO2 concentration from 0 to 40 ppb, and the ozone concentration from 200 to 700 ppb. The best agreement of the retrieved ion–ion recombination coefficient with the commonly used literature value of 1.6 × 10−6 cm3 s−1 was found at a temperature of 5 °C and a RH of 40 % (1.5 ± 0.6) × 10−6 cm3 s−1. At 20 °C and 40 % RH, the retrieved ion–ion recombination coefficient was instead (2.3 ± 0.7) × 10−6 cm3 s−1. We observed no dependency of the ion–ion recombination coefficient on ozone concentration and a weak variation with sulfur dioxide concentration. However, we observed a more than fourfold increase in the ion–ion recombination coefficient with decreasing temperature. We compared our results with three different models and found an overall agreement for temperatures above 0 °C, but a disagreement at lower temperatures. We observed a strong increase in the recombination coefficient for decreasing relative humidities, which has not been reported previously
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