[en] The accumulation of paramagnetic centers – NO₂^· and O^·− in RbNO₃ and CsNO₃ crystals under γ-irradiation at 310 K and their thermal stability has been studied. The values of the initial radiation chemical yield of NO₂^· were calculated to be ∼2.5 × 10⁻² (100 eV)⁻¹ in both nitrates. These values for O^·− are equal to 0.05 and 0.38 (100 eV)⁻¹ for RbNO₃ and CsNO₃, respectively. The heating of irradiated crystals results in the decay of NO₂^· and O^·− centers with simultaneously appearance of the ozonide ion. The mechanism for paramagnetic centers formation under γ-irradiation of RbNO₃ and CsNO₃ crystals has been discussed

[en] Full text: Numerous researches devoted to dissociation of water molecule on the surface of solid state have been performed for water vapor - solid state interface. Current experimental techniques such as X-ray scattering, LEED and neutron diffraction have helped to identify many characteristics of dissociation on solid-water interface region. In the case of 'condensed phase' - liquid water (bulk water) - solid state interface the characteristics of dissociation is essentially changes. For obtaining the characteristics of dissociation of water in 'condensed phase' the data on on behavior of double layer capacitance of the wetted surface. In this work the experimental impedance curves for water on the metals (Ni, Al, Au, Ti) and semiconductors (Si, Ge, SiC) are presented. To interpretation of the impedance measurements the suitable equivalent circuits are proposed taking into account the presence of thin oxide films on the border. It is shown that the impedance spectroscopy technique (IS) may be used in order to study the dissociation process of water molecules on the solid state surface. (authors)

[en] Complete text of publication follows. The goal of the present paper is to study the paramagnetic centers formation under γ-radiolysis of crystalline RbNO₃ and CsNO₃ at 300 K and their decay under the heating to develop the mechanism for radiolysis products formation. The RbNO₃ and CsNO₃ crystals were irradiated with ⁶⁰Co γ-rays at ∼ 310 K. The irradiated RbNO₃ and CsNO₃ crystals were thermal annealed at 393 K and 423 K, respectively. O·^- and NO₂· centers are registered in ESR spectra of irradiated crystals. The kinetics of O·^- accumulation has a nonlinear character, when for NO₂· it is linear. The values of O·^- initial radiation chemical yield - G(O·^-) are equal to 0.01 and 0.14 (100 eV)^-1 for RbNO₃ and CsNO₃, respectively, when G(NO₂·) - 0.03 (100 eV)^-0 for studied nitrates. The thermal annealing of irradiated samples results in the drop of the initial centers with simultaneously appearance of the O₃·^-, but not O₂·^-. The initial product of radiolysis of the nitrates is the complex [xNO₂^- ... O_x]. Because O₃·^- formation from O·^- under thermal annealing is possible if the molecular oxygen formed under irradiation only, then x = 2. Therefore O·^- formation is not due to the localization of the electron on the atomic oxygen of the complex. The complex [NO₂· ... O·^-] may be formed under the dissociation of the excited nitrate ion formed under irradiation. Hence, the formation of that complex in crystalline nitrates is at variance to the fact that G(O·^-) disagree with G(NO₂·). The mechanism for the paramagnetic centres formation under the radiolysis of RbNO₃ and CsNO₃ crystals and the heating can be written as follows. Under irradiation: NO₃^- + e → NO₃·^2- → [NO₂^- ... O·^-]; 2NO₃^- h → (NO₃)₂·^- → [NO₂· ... O₂ ... NO₂^-]. Under the heating: [NO₂· ... O₂ ... NO₂^-] → [NO₂· ... NO₂^-] + O₂; O₂ + [NO₂^- ... O·^-] → [NO₂^- ... O₃·^-]. Acknowledgements: This research was conducted with financial support from Federal Target Programme 'Scientific and Scientific - Pedagogic Manpower of Innovation Russia' 2009-2013 years.

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[en] Purpose: To develop a new technique, intraoperative high dose rate brachytherapy (IOHDR), to deliver localized radiation therapy intraoperatively to head and neck tumors at sites inaccessible to intraoperative electron beam radiotherapy (IOEBRT) in the skull base region. Methods: After maximal surgical resection, afterloading catheters spaced 1 cm apart embedded in custom surface applicators made of foam or silicone were placed on resected tumor beds. IOHDR was delivered in a shielded operating room using preplanned dosimetry with a nominal 10 Ci iridium-192 source in an HDR micro-Selectron afterloader. Twenty-nine patients (20 males, 9 females) ranging in age from 9 to 80 years (median=61) were irradiated intraoperatively for advanced head and neck tumors at sites inaccessible to IOEBRT. Six patients who had previously received external beam radiation (EBRT) ranging from 50 to 75 Gy, were given 15 Gy of IOHDR only. Twenty-three patients who had no prior radiation received 7.5 to 12.5 Gy IOHDR, and 45 to 50 Gy EBRT was planned post-operatively; however, six of these patients did not complete the planned EBRT. Doses to normal tissues were reduced whenever possible by shielding with lead or by displacement with gauze or retractors. Treatment time ranged from 3.8 to 23 min (median=6.5 min). Five patients received concurrent cis-platinum based chemotherapy. Results: Twenty-nine patients treated to 30 sites had local tumor control of 67% and crude survival of 72%, with the follow-up ranging from 3 to 33 months (median=21 months). In the group of 17 previously unirradiated patients who had completed full treatment (IOHDR and EBRT) to 18 sites, the local tumor control was 89%, and all of these patients survived. Tumor control in the six previously unirradiated patients who did not complete EBRT was 50% with a crude survival of 50%. In the group of six previously irradiated patients treated by IOHDR only, the local tumor control was 17% with a crude survival of 17%. No intraoperative complications were noted. The delayed morbidity included cerebrospinal fluid (CSF) leak with bone exposure (1), chronic subdural hematoma (1), septicemia (1), otitis media (1), and severe xerostomia (1). We cannot comment on long-term morbidity due to the relatively short follow-up period of 21 months. Conclusions: It is feasible to deliver IOHDR, with acceptable toxicity, to skull base tumors at sites inaccessible to IOEBRT. The use of IOHDR as a pre-radiotherapy boost produced excellent local control and survival in the selected group of patients who had no previous radiation therapy. The use of exclusive IOHDR in the previously irradiated group resulted in poor outcome, possibly due to the limitations on re-irradiation doses and/or volumes determined by normal tissue tolerance or because these patients have inherently radioresistant tumors. Higher IOHDR doses, additional EBRT, and/or chemotherapy should be considered for this group. The use of IOHDR as a pre-EBRT boost to maximize local control has a promising future in the treatment of carefully selected patients with advanced skull base tumor

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[en] Planar silver layers have been produced on the surface of porous glass (PG) membranes by multiple impregnations with an aqueous AgNO₃ solution, followed by hydrogen reduction of the salt to silver metal. In all cases, electron emission from the surface of the metallized porous glasses is observed above threshold electric fields lower than 2 V/μm. The emittance of the Ag/PG membranes decreases as the amount of silver increases above a nominal monolayer.

[en] The paper presents the results of a study on the balance of charge in accelerator TEMP–4M operating in double-pulse mode with resistance load and ion diode. Crucially, it was found, that during the switching there is no losses of accumulated charge. It means, that all accumulated charge transferred to the load. However when the charge is transferred from the Marx generator to Blumlein line the half of accumulated charge is lost. Calibration of diagnostic equipment showed a good agreement between the calculated and experimental values of voltage and current. It means, that our diagnostic system is correct for registration parameters of the ion accelerator. A distinctive feature of the ion accelerators with self-magnetically insulated diode is that there is no need to use additional energy source for the creation of an external magnetic field. That's why the efficiency of ion diodes with an external magnetic field is not more than 10–15%. The efficiency of energy conversion in self-magnetically insulated diodes will be determined by not only the efficiency of the diode, but the energy losses in the units of the accelerator. The aim of the researches is the analysis of the balance of charge in units of the ion beams pulsed generator and definition of the most significant channels of energy loss

[en] Film phosphors are obtained by adsorption of N,N'-bis(salicylidene)-1,3-propylenediamine and its halogen derivatives from their ethanol solutions by a perfluorosulfonic membrane. Fluorescence bands with maxima at 440–460 nm are determined by the polarized state of the molecules in the membrane. We propose to consider the antibonding ${\mathrm{\pi <!--\; ??\; -->}}_{\text{(N=C)}}^{\ast <!--\; ???\; -->}$ states of the azomethine fragments (HC=N–) of the molecules as emitting ones.