Synthesis and photocatalytic properties of SiO2Cd2SiO4@CdS nanocomposite powders

Inorganic composites SiO2–Cd2SiO4@CdS were synthesized. The structure and morphology of the synthesized powders were studied. The composite materials obtained are more resistant to photocorrosion under both visible and UV radiation, compared to CdS particles deposited on SiO2. The high photocatalytic activity of the synthesized SiO2–Cd2SiO4@CdS composites was demonstrated by the example of photodegradation of Nile Blue dye in water under irradiation with visible light (λ > 410 nm)

Channeling of high energy beams in nanotubes

We present simulations of particle beam channeling in carbon nanotubes and evaluate the possibilities for experimental observation of channeling effect in straight and bent nanotubes at IHEP and LNF. Different particle species are considered: protons of 1.3 and 70 GeV, and positrons of 0.5 GeV. Predictions are made for the experiments, with analysis of requirements on the quality of nanosamples and resolution of the experimental set-up. Based on Monte Carlo simulations, the capabilities of nanotube channeling technique for particle beam steering are discussed

Making Micro- and Nano-beams by Channeling in Micro- and Nano-structures

A particle beam of very small cross-section is useful in many accelerator applications including biological and medical ones. We show the capability of the channeling technique using a micron-sized structure on a surface of a single crystal, or using a nanotube, to produce beam of a cross-section down to 1 square micrometer (or nanometer). The channeled beam can be deflected and thus well separated in angle and space from the primary and scattered particles. Monte Carlo simulation is done to evaluate the characteristics of a channeled microbeam. Emittances down to 0.1-0.001 nanometer radian, and flux up to 1 million particles per square micron per second, can be achieved for protons and ions.Comment: 8 pages, 4 figure

Crystal Undulator As A Novel Compact Source Of Radiation

A crystalline undulator (CU) with periodically deformed crystallographic planes is capable of deflecting charged particles with the same strength as an equivalent magnetic field of 1000 T and could provide quite a short period L in the sub-millimeter range. We present an idea for creation of a CU and report its first realization. One face of a silicon crystal was given periodic micro-scratches (grooves), with a period of 1 mm, by means of a diamond blade. The X-ray tests of the crystal deformation have shown that a sinusoidal-like shape of crystalline planes goes through the bulk of the crystal. This opens up the possibility for experiments with high-energy particles channeled in CU, a novel compact source of radiation. The first experiment on photon emission in CU has been started at LNF with 800 MeV positrons aiming to produce 50 keV undulator photons.Comment: Presented at PAC 2003 (Portland, May 12-16

Progress in crystal extraction and collimation

Recent IHEP Protvino experiments show efficiencies of crystal-assisted slow extraction and collimation of 85.3+-2.8%, at the intensities of the channeled beam on the order of 10^12 proton per spill of 2 s duration. The obtained experimental data well follows the theory predictions. We compare the measurements against theory and outline the theoretical potential for further improvement in the efficiency of the technique. This success is important for the efficient use of IHEP accelerator and for implementation of crystal-assisted collimation at RHIC and slow extraction from AGS onto E952, now in preparation. Future applications, spanning in the energy from order of 1 GeV (scraping in SNS, slow extraction from COSY and medical accelerators) to order of 1 TeV and beyond (scraping in Tevatron, LHC, VLHC), can benefit from these studies.Comment: 7pp. Presented at HEACC 2001 (Tsukuba, March 25-30

Experience of rectosacropexy in treatment of patients with rectum prolapse

Aim of investigation. To analyze authors’ experience of rectosacropexy results at prolapse of the rectum. Material and methods. Original study included 137 patients who underwent surgery for prolapse of rectum in the State scientific center of coloproctology from January, 2007 to December, 2013. The main group have included 60 patients (43,8%) who had rectosacropexy, control group included 77 patients (56,2%) after back loop rectopexy.Results. Control examination was carried out in 24 patients (40%) of the main and in 26 patients (33,8%) of the control group. Average time of follow-up was respectively 9,8±2,0 months and 34,2±17,8 months. Relapse was diagnosed in 2 patients (7,6%) after back loop rectopexy. After surgical treatment of rectal prolapse statistically significant improvement of anal sphincter pressure was diagnosed in both groups at I and II degree of sphincter insufficiency. Application of rectosacropexy corrects pelvic floor descent syndrome and evacuatory function of the rectum. No deterioration of large intestinal transit after rectosacropexy was revealed (р>0,05). After back loop rectopexy deterioration of large intestinal emptying (р<0,05) was significant.Conclusions. Rectosacropexy is effective method of rectum prolapse treatment and improves function of anal sphincter in postoperative period, corrects pelvic floor descent syndrome and cause no constipation