Polar mesosphere summer echoes: a comparison of simultaneous observations at three wavelengths

On 5 July 2005, simultaneous observations of Polar Mesosphere Summer Echoes (PMSE) were made using the EISCAT VHF (224 MHz) and UHF (933 MHz) radars located near Tromsø, Norway and the ALWIN VHF radar (53.5 MHz) situated on Andøya, 120 km SW of the EISCAT site. During the short interval from 12:20 UT until 12:26 UT strong echoes at about 84 km altitude were detected with all three radars. The radar volume reflectivities were found to be 4×10<sup>−13</sup> m<sup>−1</sup>, 1.5×10<sup>−14</sup> m<sup>−1</sup> and 1.5×10<sup>−18</sup> m<sup>−1</sup> for the ALWIN, EISCAT-VHF and UHF radars, respectively. We have calculated the reflectivity ratios for each pair of radars and have compared them to ratios obtained from the turbulence-theory model proposed by Hill (1978a). We have tested different values of the turbulent energy dissipation rate ε and Schmidt number <i>S<sub>c</sub></i>, which are free parameters in the model, to try to fit theoretical reflectivity ratios to the experimental ones. No single combination of the parameters ε and <i>S<sub>c</sub></i> could be found to give a good fit. Spectral widths for the EISCAT radars were estimated from the spectra computed from the autocorrelation functions obtained in the experiment. After correction for beam-width broadening, the spectral widths are about 4 m/s for the EISCAT-VHF and 1.5–2 m/s for the UHF radar. However, according to the turbulence theory, the spectral widths in m/s should be the same for both radars. We also tested an incoherent scatter (IS) model developed by Cho et al. (1998), which takes into account the presence of charged aerosols/dust at the summer mesopause. It required very different sizes of particles for the EISCAT-VHF and UHF cases, to be able to fit the experimental spectra with model spectra. This implies that the IS model cannot explain PMSE spectra, at least not for monodisperse distributions of particles

Kink-antikink interactions in the double sine-Gordon equation and the problem of resonance frequencies

We studied the kink-antikink collision process for the "double sine-Gordon" (DSG) equation in 1+1 dimensions at different values of the potential parameter $R>0$. For small values of $R$ we discuss the problem of resonance frequencies. We give qualitative explanation of the frequency shift in comparison with the frequency of the discrete level in the potential well of isolated kink. We show that in this region of the parameter $R$ the effective long-range interaction between kink and antikink takes place.Comment: 9 pages, LaTeX, 4 figures (eps

P38α-MAPK Signaling Inhibition Attenuates Soleus Atrophy during Early Stages of Muscle Unloading

To test the hypothesis that p38α-MAPK plays a critical role in the regulation of E3 ligase expression and skeletal muscle atrophy during unloading, we used VX-745, a selective p38α inhibitor. Three groups of rats were used: non-treated control (C), 3 days of unloading/hindlimb suspension (HS), and 3 days HS with VX-745 inhibitor (HSVX; 10 mg/kg/day). Total weight of soleus muscle in HS group was reduced compared to C (72.3 ± 2.5 vs 83.0 ± 3 mg, respectively), whereas muscle weight in the HSVX group was maintained (84.2 ± 5 mg). The expression of muscle RING-finger protein-1 (MuRF1) mRNA was significantly increased in the HS group (165%), but not in the HSVX group (127%), when compared with the C group. The expression of muscle-specific E3 ubiquitin ligases muscle atrophy F-box (MAFbx) mRNA was increased in both HS and HSVX groups (294% and 271%, respectively) when compared with C group. The expression of ubiquitin mRNA was significantly higher in the HS (423%) than in the C and HSVX (200%) groups. VX-745 treatment blocked unloading-induced upregulation of calpain-1 mRNA expression (HS: 120%; HSVX: 107%). These results indicate that p38α-MAPK signaling regulates MuRF1 but not MAFbx E3 ligase expression and inhibits skeletal muscle atrophy during early stages of unloading

Design and Manufacture of the Superconducting Bus-bars for the LHC Main Magnets

The main magnets of the LHC are series-connected electrically in different powering circuits by means of superconducting bus-bars, carrying a maximum current of 13 kA. These superconducting bus-bars consist of a superconducting cable thermally and electrically coupled to a copper profile all along the length. The function of the copper profile is essentially to provide an alternative path for the current in case the superconducting cable loses its superconducting state and returns to normal state because of a transient disturbance or of a normal zone propagation coming from the neighbouring magnets. When a superconducting bus-bar quenches to normal state its temperature must always stay below a safe values of about 100°C while the copper is conducting. When a resistive transition is detected, the protection systems triggers the ramping down of the current from 13000 A to 0. The ramp rate must not exceed a maximum value to avoid the transition of magnets series-connected in the circuit. This paper concerns the design and the manufacture of the high current superconducting bus-bars needed to interconnect the magnetic elements of the main dipoles, the main quadrupoles of the arcs and of the dispersion suppressors of the LHC

Research of lithium sorption by KU-2-8 cation exchanger from model solutions simulating geothermal fluids in the dynamic mode

The extraction of chemical compounds from hydromineral raw materials is currently a promising objective. The geothermal deposits in the Kamchatka Territory should be considered as possible sources of lithium, boron and other chemical compounds. Their economic efficiency is justified by the complexity of the use of resources of geothermal fluids. The article presents data obtained as a result of experimental studies of lithium sorption by KU-2-8 cation exchanger from model solutions that simulate geothermal fluids in the dynamic mode. It was shown that in the first phase of sorption, ion exchange results in the absorption of lithium and sodium ions by the hydrogen form of cation exchanger up to the degree of cation exchanger saturation by 78 %. After that, the displacement of lithium ions by sodium ions is observed. The intermediate solutions were obtained in which the molar ratio of Li/Na is 80 times higher than in the initial solution. To separate sodium and lithium, it is proposed to use the lithium form of cation exchanger obtained using a portion of lithium chloride concentrate. The separation occurs due to the displacement of lithium ions by sodium ions. The effluent has a molar ratio of Li/Na = 10.4. The regeneration is carried out with 1 n hydrochloric acid, while the concentration coefficient of sodium chloride equals three

Funcionamento de causativas emotivas em complexos semânticos categoriais

The linguistics of emotions currently occupies an important position in research. Emotions, permeating all human activities, are reflected at all levels of the language. This determines the vast interest of linguists to them. The authors of the article consider the class of emotive causatives and its functional semantic features. This class is a subclass of causatives, the semantics of which is associated with the impact in order to evoke certain emotions. The functional features of these units lie in the fact that they are the result of intercategorical interaction. The language unit forms categorical semantic complexes while interacting in speech with elements of the environment and other categories within the framework of a categorical situation. The authors of the article analyze emotive-causative categorical semantic complex. Expression is the product of emotion, and emotions arise under the influence of means of expressiveness. Thus, using the example of emotive causatives, we observe intercategorical interaction of different-level elements of the language system in speech.La lingüística de las emociones ocupa actualmente un lugar importante en la investigación. Las emociones, que impregnan todas las actividades humanas, se reflejan en todos los niveles del idioma. Esto determina el gran interés de los lingüistas por ellos. Los autores del artículo consideran la clase de causativas emotivas y sus características semánticas funcionales. Esta clase es una subclase de causativos, cuya semántica se asocia con el impacto para evocar ciertas emociones. Las características funcionales de estas unidades radican en el hecho de que son el resultado de la interacción intercategórica. La unidad de lenguaje forma complejos semánticos categóricos mientras interactúa en el habla con elementos del entorno y otras categorías dentro del marco de una situación categórica. Los autores del artículo analizan el complejo semántico categórico emotivo-causativo. La expresión es producto de la emoción y las emociones surgen bajo la influencia de los medios de expresividad. Por lo tanto, utilizando el ejemplo de los causativos emotivos, observamos la interacción intercategórica de elementos de diferentes niveles del sistema del lenguaje en el habla.A lingüística das emoções ocupa atualmente uma posição importante na pesquisa. As emoções, que permeiam todas as atividades humanas, são refletidas em todos os níveis da linguagem. Isso determina o vasto interesse dos linguistas por eles. Os autores do artigo consideram a classe dos causativos emotivos e suas características semânticas funcionais. Esta classe é uma subclasse de causativos, cuja semântica está associada ao impacto para evocar certas emoções. As características funcionais dessas unidades residem no fato de serem o resultado de uma interação intercategoria. A unidade de linguagem forma complexos semânticos categóricos ao interagir na fala com elementos do ambiente e outras categorias dentro da estrutura de uma situação categórica. Os autores do artigo analisam o complexo semântico categórico emotivo-causativo. A expressão é o produto da emoção, e as emoções surgem sob a influência de meios de expressividade. Assim, usando o exemplo dos causativos emotivos, observamos a interação intercategorica de elementos de diferentes níveis do sistema de linguagem na fala

Metal-semiconductor (semimetal) superlattices on a graphite sheet with vacancies

It has been found that periodically closely spaced vacancies on a graphite sheet cause a significant rearrange-ment of its electronic spectrum: metallic waveguides with a high density of states near the Fermi level are formed along the vacancy lines. In the direction perpendicular to these lines, the spectrum exhibits a semimetal or semiconductor character with a gap where a vacancy miniband is degenerated into impurity levels.Comment: 4 pages, 3 figure