The solar energetic particles (SEPs) effect in the Earth's atmosphere is presented and considered in terms of energy deposition and ionisation produced by SEPs passing through the atmosphere. We ...choose the most powerful solar energetic particle events recorded in the Earth environment during 1956-2005. Evaluation of SEPs energy spectra was done on the basis of peak particle fluxes measured during these events by different instruments in the 10 MeV - few GeV energy range. We performed Monte Carlo simulations using GEANT4 to determine energy deposition and ion production rate in the atmosphere during selected events. We discussed the cutoff-rigidity dependence obtained results.
An overview is presented of basic results and recent developments in the field of cosmic ray induced ionisation in the atmosphere, including a general introduction to the mechanism of cosmic ray ...induced ion production. We summarize the results of direct and indirect measurements of the atmospheric ionisation with special emphasis to long-term variations. Models describing the ion production in the atmosphere are also overviewed together with detailed results of the full Monte-Carlo simulation of a cosmic ray induced atmospheric cascade. Finally, conclusions are drawn on the present state and further perspectives of measuring and modeling cosmic ray induced ionisation in the terrestrial atmosphere.
We report comprehensive, demonstrably contaminant-free measurements of binary particle formation rates by sulfuric acid and water for neutral and ion-induced pathways conducted in the European ...Organization for Nuclear Research Cosmics Leaving Outdoor Droplets chamber. The recently developed Atmospheric Pressure interface-time of flight-mass spectrometer was used to detect contaminants in charged clusters and to identify runs free of any contaminants. Four parameters were varied to cover ambient conditions: sulfuric acid concentration (105 to 109 mol cm−3), relative humidity (11% to 58%), temperature (207 K to 299 K), and total ion concentration (0 to 6800 ions cm−3). Formation rates were directly measured with novel instruments at sizes close to the critical cluster size (mobility size of 1.3 nm to 3.2 nm). We compare our results with predictions from Classical Nucleation Theory normalized by Quantum Chemical calculation (QC-normalized CNT), which is described in a companion paper. The formation rates predicted by the QC-normalized CNT were extended from critical cluster sizes to measured sizes using the UHMA2 sectional particle microphysics model. Our results show, for the first time, good agreement between predicted and measured particle formation rates for the binary (neutral and ion-induced) sulfuric acid-water system. Formation rates increase with RH, sulfuric acid, and ion concentrations and decrease with temperature at fixed RH and sulfuric acid concentration. Under atmospheric conditions, neutral particle formation dominates at low temperatures, while ion-induced particle formation dominates at higher temperatures. The good agreement between the theory and our comprehensive data set gives confidence in using the QC-normalized CNT as a powerful tool to study neutral and ion-induced binary particle formation in atmospheric modeling.
We studied the effects of S100b protein in doses stimulating (500 and 50 ng) or inhibiting (5 ng) apoptosis in nerve cells on acquisition, retention, and retrieval of extinction of the acoustic ...startle response and conditioned fear in adult rats. After application to the vermis of the cerebellum S100b protein in doses of 500 and 50 ng impaired, while in a dose of 5 ng facilitated acquisition of both forms of defensive behavior. Different behavioral effects of S100b protein are probably related to its pro- and antiapoptotic effects on cerebellar cells relevant to the studied forms of behavior. Our results suggest that regulators of apoptosis are involved in the mechanisms of learning and memory.
The intermolecular charge-transfer complex (CTC) between the conjugated polymer MEH-PPV and the low-molecular organic acceptor trinitrofluorenone (TNF) has been studied by Raman and optical ...absorption spectroscopy. On mixing MEH-PPV with TNF, an absorption band due to the CTC appeared in the optical gap of the polymer, whereas, in the Raman spectra, characteristic bands of the polymer are shifted and their widths and intensities change. The low-frequency shift of the strongest band at 1580 cm{sup -1} in the Raman spectrum of the polymer, assigned to the symmetric stretching vibration of the phenyl group, is shown to be due to electron density transfer from the {pi}-conjugated system of the polymer to the acceptor and is as large as 5 cm{sup -1}, which corresponds to a charge transfer on the order of 0.1e{sup -1}. Even at a low acceptor concentration (one TNF molecule per 10 monomer units of the polymer), most Raman-active conjugated chains are involved in the CTC. It is suggested that conjugated segments of the polymer can form a CTC of variable composition MEH-PPV: TNF = 1: X, where 0.1 {<=} X {<=} 0.5 (for each monomer unit of the polymer), and one TNF molecule can thereby interact with two conjugated segments of MEH-PPV. The conjugated polymer chains involved in the CTC can become more planar, and their interaction with the local environment can noticeably change; however, their conjugation length, most likely, remains unaltered.
The objectives and scientific tasks of the planned space experiment “Solntse-Terahertz” to be performed onboard the ISS Russian Segment are briefly described in the paper. In particular, the aim of ...the experiment is to study uninvestigated solar electromagnetic emission in the terahertz domain, in ~ 1012 – 1013 Hz (300-30 µm) frequency range. It is expected to obtain new data on solar active region emission including solar flare emission. These data are necessary to clarify the nature of solar activity and construct physical model of charged particle acceleration in active regions during solar flares and other astrophysical objects. We focus on the telescope optical system design and evaluation of main characteristics of this system. Results of simulations and comparison with the experimental verification of obtained characteristics are presented. A close correlation of the estimations and experimental results was obtained. As a result, main parameters of the telescope optical system of experimental hardware “Solntse-Terahertz” were determined.
Key words: Sun, solar flares, terahertz emission, optical system.
To study changes in microcirculation of the lower urinary tract in different diseases we used laser analyzer of capillary circulation LAKK-01. The control group consisted of 25 volunteers, the study ...group--of 65 patients with different vesico-urethral diseases. Normal values of microcirculation in the wall of the urinary bladder, prostatic gland and urethra were determined. These values were significantly reduced in patients with vesico-urethral disorders. Thus, alterations in microcirculation in different pathological conditions of the vesicourethral segment confirm the hypothesis of a direct involvement of microcirculation disorders in pathogenesis of many urological diseases.
PDF
