Magnetic reconnection and current sheets in 2D and 3D magnetic configurations

Experimental results are presented on the study magnetic reconnection phenomena and current sheet formation and evolution in 2D and 3D magnetic configurations with some topological singularities: null-lines, null points, singular lines. Current sheet evolution in 2D fields with null-lines manifests qualitative agreement with principal features of flare-type phenomena. Current sheet formation was revealed to occur in various 3D magnetic configurations, both with and without isolated magnetic null-points, specifically in agnetic configurations with Xlines. Results demonstrate self-organization of current sheets to be a general process for plasma dynamics in nonuniform magnetic fields

Ultra-high energy cosmic ray investigations by means of EAS muon density measurements

A new approach to investigations of ultra-high energy cosmic rays based on the ground-level measurements of the spectra of local density of EAS muons at various zenith angles is considered. Basic features of the local muon density phenomenology are illustrated using a simple semi-analytical model. It is shown that muon density spectra are sensitive to the spectrum slope, primary composition, and to the features of hadronic interaction. New experimental data on muon bundles at zenith angles from 30 degrees to horizon obtained with the coordinate detector DECOR are compared with CORSIKA-based simulations. It is found that measurements of muon density spectra in inclined EAS give possibility to study characteristics of primary cosmic ray flux in a very wide energy range from 10^15 to 10^19 eV.Comment: 7 pages, 7 figures. Presented at CRIS-2006, Catania, Italy, May 29 - June 2, 2006. Accepted for publication in Nucl. Phys. B (Proc. Suppl.

Characteristics of ADS target irradiated by 200…400 MeV proton beam

The problems of target choice for compact ADS with reactor thermal power 200…400 MW and 200…400 MeV proton beam are considered. Simulation results of neutron yield from fissile and non-fissile targets are presented and the optimal target sizes are calculated. The principal target design characteristics and its thermal condition are also considered.Рассмотрены вопросы выбора мишени для компактной электроядерной установки с мощностью реактора 200…400 МВт и энергией протонов 200…400 МэВ. Представлены результаты моделирования выходов нейтронов из размножающих и неразмножающих мишеней и определены оптимальные размеры мишени. Рассмотрены особенности конструкции мишени и вопросы ее температурного состояния.Розглянуто питання вибору мішені для компактної електроядерної установки з потужністю реактора 200…400 МВт і енергією протонів 200…400 МеВ. Представлено результати моделювання виходів нейтронів із розмножуючих і нерозмножуючих мішеней та визначені оптимальні розміри мішені. Розглянуто особли-вості конструкції мішені і питання її температурного стану

Study of polytopic membrane protein topological organization as a function of membrane lipid composition.

A protocol is described using lipid mutants and thiol-specific chemical reagents to study lipid-dependent and host-specific membrane protein topogenesis by the substituted-cysteine accessibility method as applied to transmembrane domains (SCAM). SCAM is adapted to follow changes in membrane protein topology as a function of changes in membrane lipid composition. The strategy described can be adapted to any membrane system

Linking Distributed Optimization Models for Food, Water, and Energy Security Nexus Management

Traditional integrated modeling (IM) is based on developing and aggregating all relevant (sub)models and data into a single integrated linear programming (LP) model. Unfortunately, this approach is not applicable for IM under asymmetric information (ASI), i.e., when “private” information regarding sectoral/regional models is not available, or it cannot be shared by modeling teams (sectoral agencies). The lack of common information about LP submodels makes LP methods inapplicable for integrated LP modeling. The aim of this paper is to develop a new approach to link and optimize distributed sectoral/regional optimization models, providing a means of decentralized cross-sectoral coordination in the situation of ASI. Thus, the linkage methodology enables the investigation of policies in interdependent systems in a “decentralized” fashion. For linkage, the sectoral/regional models do not need recoding or reprogramming. They also do not require additional data harmonization tasks. Instead, they solve their LP submodels independently and in parallel by a specific iterative subgradient algorithm for nonsmooth optimization. The submodels continue to be the same separate LP models. A social planner (regulatory agency) only needs to adjust the joint resource constraints to simple subgradient changes calculated by the algorithm. The approach enables more stable and resilient systems’ performance and resource allocation as compared to the independent policies designed by separate models without accounting for interdependencies. The paper illustrates the application of the methodology to link detailed energy and agricultural production planning models under joint constraints on water and land use

New technique and results of cosmic ray investigations in the energy interval 1015–1019 eV

New technique of EAS investigations based on the measurements of local muon density spectra (LMDS) is developed. Application of this method to investigations of inclined EAS allows exploration of CR energy interval from 10 15 to 10 19 eV by means of a relatively small detector with area ∼100m 2 due to very strong dependence of EAS muon density on zenith angle. During 2002-2007, long-term NEVOD- DECOR experiment (about 20,000h live time) was conducted, and more than two million muon bundles in zenith angle interval 30-88 degrees were registered. Comparison of experimental data with results of CORSIKA-based simulations showed that the new method is sensitive to all main peculiarities of CR energy spectrum: the knee, increase of the energy spectrum slope with energy, the second knee. But the observed progressive excess of muon bundles with the increase of primary CR energy in comparison with simulations (even for pure iron composition) can indicate the appearance of new processes of muon generation. In this case, for correct investigations of EAS, the experimental arrays must be supplemented by detectors which can measure or evaluate the energy of muons