The polyacrylic acid/modified chitosan capsules with tunable release of small hydrophobic probe and drug

© 2015 Elsevier B.V. Nanocapsules (≤200. nm) with a protection effect toward small hydrophobic guests (p-nitrophenyl laurate and acetylsalicylic acid, aspirin) and a tunable sustained release behavior have been fabricated through the layer-by-layer deposition of polyacrylic acid and modified chitosan. Cationic surfactant, cetyltrimethylammonium bromide, was used to increase the affinity of polyelectrolyte to the substrate. The release profile was monitored through original protocol involving a fast cleavage of the substrate released and a spectrophotometric control of the product. The shell permeability of the capsules and hence their protective effect may be tuned through the variation of the number of layers deposited, the sonication, and the adjustment of solution pH. Importantly, the dispersed loads serving as a template for the capsule fabrication may control their properties, including shell permeability

ОЦЕНКА НАВЕДЕННОЙ АКТИВНОСТИ В ОБЛУЧАЕМЫХ МАТЕРИАЛАХ ПРИ ИСПОЛЬЗОВАНИИ ОТРАБОТАВШЕГО ТОПЛИВА РЕАКТОРА ВВЭР-1200 В РАДИАЦИОННЫХ ТЕХНОЛОГИЯХ И ПУТИ ЕЕ ОСЛАБЛЕНИЯ

Technical ability to use the VVER-1200 spent nuclear fuel as a source of γ-radiation to solve radiation technology problems is substantiated. The technology area for these sources is limited to the problems which do not require large absorbed doses. EGSnrs program is used to determine the absorbed dose in irradiated materials from the spent fuel assemblies (SFA). This program is a computer code system, which forms a versatile package for simulation by Monte Carlo method the bound transfer of electrons and gamma-rays with energy above a few keV. The design of the radiation installation with the irradiator based on the SFA or composed of a number of fuel rods is proposed. The irradiator is located on the bottom of the pool and can be raised above the water level, or remain under its surface, if necessary. This layer of water plays a role of the shield and decreases neutron activation of irradiated material to a safe level. In some cases, boric acid dissolved in water allows reduction of the thickness of the water layer. Results of the evaluation of materials irradiation time and the thickness of the water shield are presented. Обосновывается техническая возможность использования отработавшего ядерного топлива реактора ВВЭР- 1200 в качестве источника гамма-излучения в радиационных технологиях, не требующих больших поглощенных доз. Для определения мощности поглощенной дозы в облучаемых материалах от отработавшей тепловыделяющей сборки (ОТВС) применена программа EGSnrc, представляющая систему компьютерных кодов, которая образует универсальный пакет для моделирования методом Монте-Карло связанного переноса электронов и γ-квантов применительно к энергиям выше нескольких килоэлектронвольт. Предложена конструкция радиационной установки, в которой облучатель на основе ОТВС или составленный из ряда твэлов, находящийся на дне бассейна, для облучения может подниматься как выше уровня воды, так и при необходимости оставаться под ее поверхностью. При этом слой воды между облучателем и облучаемым материалом играет роль экрана, ослабляющего наведенную нейтронную активность до безопасного уровня. В некоторых случаях уменьшить толщину слоя воды позволяет растворенная в воде борная кислота. Представлены результаты оценки времени облучения материалов и толщины экрана.

Исследования в областях физики ядерных реакторов и ионизирующих излучений в Объединенном институте энергетических и ядерных исследований - Сосны НАН Беларуси

The history of the development of the science researches on nuclear reactor physics and techniques, description of the experimental and calculate-analytical base of JNE and JINPR - Sosny as well as the scientific links with other organizations in the past and nowadays are presented. A few new tendency of the fundamental science researches on increasing nuclear and radiation NPP safety in the future and the ways of using radiation of the nuclear spent fuel are described.В связи с началом строительства АЭС в Республике Беларусь представляется целесообразным ознакомить общественность Беларуси с характером и результатами некоторых работ в Институте ядерной энергетики (ИЯЭ) АН БССР и его правопреемнике Объединенном институте энергетических и ядерных исследований -Сосны (ОИЭЯИ - Сосны) НАН Беларуси в области физики ядерных реакторов и использования радиоактивных излучений, что является основной целью настоящей статьи. Приводятся история развития в Беларуси с 1958 г. научных исследований по физике и технике ядерных реакторов, описание экспериментальной и рас-четно-аналитической базы ИЯЭ и ОИЭЯИ - Сосны, научных связей с другими организациями в прошлом и в настоящее время. Представлены некоторые новые направления фундаментальных научных исследований по повышению ядерной и радиационной безопасности АЭС

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Evidence for the η_b(1S) Meson in Radiative Υ(2S) Decay

We have performed a search for the η_b(1S) meson in the radiative decay of the Υ(2S) resonance using a sample of 91.6 × 10^6 Υ(2S) events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at E_γ = 609.3^(+4.6)_(-4.5)(stat)±1.9(syst) MeV, corresponding to an η_b(1S) mass of 9394.2^(+4.8)_(-4.9)(stat) ± 2.0(syst) MeV/c^2. The branching fraction for the decay Υ(2S) → γη_b(1S) is determined to be [3.9 ± 1.1(stat)^(+1.1)_(-0.9)(syst)] × 10^(-4). We find the ratio of branching fractions B[Υ(2S) → γη_b(1S)]/B[Υ(3S) → γη_b(1S)]= 0.82 ± 0.24(stat)^(+0.20)_(-0.19)(syst)

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30