Active Monitoring and Decision Making Problem

Active monitoring and problem of non-stable of sound signal parameters in the regime of piling up response signal of environment is under consideration. Math model of testing object by set of weak stationary dynamic actions is offered. The response of structures to the set of signals is under processing for getting important information about object condition in high frequency band. Making decision procedure by using researcher’s heuristic and aprioristic knowledge is discussed as well. As an example the result of numerical solution is given

Model of Active Structural Monitoring and Decision-making for Dynamic Identification of Buildings, Monuments and Engineering Facilities

Structural monitoring and dynamic identification of the manmade and natural hazard objects is under consideration. Math model of testing object by set of weak stationary dynamic actions is offered. The response of structures to the set of signals is under processing for getting important information about object condition in high frequency band. Making decision procedure into active monitoring system is discussed as well. As an example the monitoring outcome of pillar-type monument is given

Coupling of COAMPS and WAVETECH with Improved Wave Physics

The Model Coupling Executable Library (MCEL), developed at the University of Southern Mississippi\u27s Center of Higher Learning, has been successfully used to couple the Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) and the ocean wave model WAVEWATCH. An example of its application is shown for Hurricane Gordon, showing that two-way coupling results affects boundary layer physics differently than one-way coupling --- in this case, resulting in larger o z and, consequently, larger surface fluxes and a more intense hurricane. However, since analyzing MCEL is difficult because the wave physics is inaccurate, improvements to the wave algorithms are also part of the deliverables. A new analytical expression for the wind/wave growth factor has been derived based on normal modes analysis and rapid distortion theory valid for all wave regimes except for tropical cyclone conditions. This new algorithm is validated against a numerical simulation of the Reynolds-stress transport equations and matches well. In contrast, other wave growth expression used in ocean models like the WAve Model (WAM) and WAVEWATCH do not produce the same results, with larger wave growth values peaking at smaller wave age values. These differences are attributed to the application of curve fitting by the other algorithms, while the new formulation is an analytical expression derived from first principles and includes factors missing in previous schemes such as turbulent interaction. If the Reynolds-stress transport equations solutions are reasonably accurate, it indicates that all the previous wave growth schemes, including WAVEWATCH, have serious deficiencies. Another unique result from this work includes a second analytical wave growth formulation valid for tropical cyclone conditions. An unexpected problem occurred with WAVEWATCH when it was discovered the roughness values are often one to two orders of magnitude too large. To circumvent this problem, the algorithm of Nordeng has been coded to compute roughness length for WAVEWATCH. This algorithm is a complicated iterative procedure involving integral expressions where turbulent stress, wave-induced stress, roughness length, and wave growth must converge

Theoretical Evaluations of the Fission Cross Section of the 77 eV Isomer of 235-U

We have developed models of the fission barrier (barrier heights and transition state spectra) that reproduce reasonably well the measured fission cross section of $^{235}$U from neutron energy of 1 keV to 2 MeV. From these models we have calculated the fission cross section of the 77 eV isomer of $^{235}$U over the same energy range. We find that the ratio of the isomer cross section to that of the ground state lies between about 0.45 and 0.55 at low neutron energies. The cross sections become approximately equal above 1 MeV. The ratio of the neutron capture cross section to the fission cross section for the isomer is predicted to be about a factor of 3 larger for the isomer than for the ground state of $^{235}$U at keV neutron energies. We have also calculated the cross section for the population of the isomer by inelastic neutron scattering form the $^{235}$U ground state. We find that the isomer is strongly populated, and for $E_n = 1 MeV$ the $(n,n'\gamma)$ cross section leading to the population of the isomer is of the order of 0.5 barn. Thus, neutron reaction network calculations involving the uranium isotopes in a high neutron fluence are likely to be affected by the 77 eV isomer of $^{235}$U. With these same models the fission cross sections of $^{233}$U and $^{237}$U can be reproduced approximately using only minor adjustments to the barrier heights. With the significant lowering of the outer barrier that is expected for the outer barrier the general behavior of the fission cross section of $^{239}$Pu can also be reproduced.Comment: 17 pages including 8 figure

Detection of hidden explosives and drugs

Technical discussions of advanced mass spectrometry methods for explosives and drug detection are presented. The discussions are part of an effort to develop fast neutron alternative technologies and optimal synergistic detection systems. Topics covered include: (1) general assessment of detection applications of neutronic techniques, (2) the US Argonne National Laboratory inelastic scattering approach; (3) the Russian Kurchatov Institute elastic scattering approach, and (4) benefits of combining the Argonne and Kurchatov approaches. Specific areas for modeling and analysis are noted. 11 refs., 8 figs

Electrochemical reduction of multilayer graphene oxide in alkaline electrolyte

The results of the study of the electrochemical reduction of multilayer graphene oxide in the potentiostatic mode are presented and the possibility of using alkaline electrolyte (KOH) with the concentration below 0.1 M is shown. The identification of the electrochemically reduced graphene oxide was carried out using the XRD, FTIR and Raman-spectroscopy methods. Applying the method of Raman spectroscopy the increase in the intensity of the G and 2D bands, indicating the formation of few-layer forms of reduced graphene oxide was found. The surface morphology of the electrochemically reduced graphene oxide was studied by means of the SEM method

МОДИФИКАЦИЯ ЭПОКСИДНЫХ ПОЛИМЕРОВ НАНОДИСПЕРСНЫМ ОКСИДОМ АЛЮМИНИЯ

The aim of this work was to improve the physical, chemical and mechanical properties of epoxy composites with the use of nanosized aluminium oxide. The studies proved the possibility of directional control of the operational properties of epoxy composites by the use of small additions of nanosized aluminium oxide ensuring the creation of epoxy composites with high performance, satisfying the requirements of most industries. The rational content of aluminium oxide as a nanostructuring additive in an epoxy composition was selected (0,05 parts by weight). It ensures an increase in the complex of physico-mechanical properties (the breaking stress increases 3.3-fold, and the flexural modulus increases by 27%, the breaking stress in compression improves by 43%, the breaking stress and the tensile modulus of elasticity increases by 47-50%, the toughness increases 3-fold, and the hardness increases by 67%), while maintaining heat resistance. The introduction of nanosized aluminium oxide changes the parameters of the epoxy oligomer curing kinetics: the gelation duration increases from 45 to 75 minutes, and the duration of cure, from 53 to 100 minutes, while the maximum curing temperature is practically unchanged. Thus, the developed materials may be used for sealing electronic articles, for impregnating and filling components in aircraft engineering, shipbuilding and, automotive industry.Целью данной работы являлось повышение физико-химических и механических свойств эпоксидных композитов с применением в качестве структурирующей добавки нанодисперсного оксида алюминия. В результате проведенных исследований доказана возможность направленного регулирования эксплуатационных свойств эпоксидных композитов за счет использования малых добавок наноразмерного Al2O3, обеспечивающего создание эпоксидных композитов с высокими эксплуатационными свойствами, удовлетворяющими требованиям большинства отраслей промышленности. Выбрано рациональное содержание Al2O3 как наноструктурирующей добавки в составе эпоксидной композиции (0.05 масс. ч.), обеспечивающее повышение изученного комплекса физико-механических свойств: в 3.3 раза возрастает разрушающее напряжение и на 27% повышается модуль упругости при изгибе, на 43% повышается разрушающее напряжение при сжатии, на 47-50% возрастает разрушающее напряжение и модуль упругости при растяжении, в 3 раза возрастает ударная вязкость, а также на 67% возрастает твердость, при сохранении термостойкости. Установлено, что введение Al2O3 оказывает влияние на процессы структурообразования эпоксидной композиции при отверждении - увеличивается продолжительность гелеобразования с 45 до 75 мин и продолжительность отверждения с 53 до 100 мин, при этом максимальная температура отверждения не изменяется. Таким образом, разработанные материалы могут быть использованы для герметизации изделий электронной техники, для пропитки и заливки узлов в авиа-, судо- и автомобилестроении

The neutron and its role in cosmology and particle physics

Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic