On the simultaneous generation of radio and soft X-ray emission by AXP 4U 0142+61

In the present paper we study the possibility of a simultaneous generation of radio waves and soft X-rays by means of the quasi-linear diffusion (QLD) in the anomalous pulsar AXP 4U 0142+61. Considering the magnetosphere composed of the so-called beam component and the plasma component respectively, we argue that the frozen-in condition will inevitably lead to the generation of the unstable cyclotron waves. These waves, via the QLD, will in turn influence the particle distribution function, leading to certain values of the pitch angles, thus to an efficient synchrotron mechanism, producing soft X-ray photons. We show that for physically reasonable parameters of magnetospheric plasma, the QLD can provide generation of radio waves in the following interval 40 MHz - 111 MHz connected to soft X-rays for the domain 0.3 keV - 1.4 keV.

Electron Kinetic Instability Driven by Electron Temperature Anisotropy and Electron Beam in the Solar Wind

<p>Electron temperature anisotropy instabilities are believed to constrain the distributions of the electron parallel and perpendicular temperatures in the solar wind. When the electron perpendicular temperature is larger than the parallel temperature, the whistler instability is normally stronger than the electron mirror instability. While the electron parallel temperature is larger than the perpendicular temperature, the electron oblique firehose instability dominates the parallel firehose instability. Therefore, previous studies proposed the whistler and electron oblique firehose instabilities constraint on the electron dynamics in the solar wind. Based on the fact that there always exists the differential drift velocity among different electron populations, we consider the electron kinetic instability in the plasmas containing the electron anisotropic component and the electron beam component. Consequently, we give a comprehensive electron kinetic instability analysis in the solar wind. Furthermore, we propose that the electron acoustic/magneto-acoustic instability can arise in the low electron beta regime, and the whistler electron beam instability can be triggered in a wide beta regime. These two instabilities can provide a constraint on the electron beam velocity. Moreover, we find a new instability in the regime of the electron beta ~ 1, and this instability produces obliquely-propagating fast-magnetosonic/whistler waves. These results would be helpful for distinguishing the electron instability and for analyzing the constraint mechanism on the electron temperature distribution in the solar wind.</p>

Optimal Method for Identification of Cracks in Different Beams using Fuzzy with Elephant Based Neural Network

Failure of Structures i.e., beams can be avoided by identifying the damage in the structure at its beginning and proper retrofitting. Recently, the researchers created a structure to recognize crack damage using a cracked beam component model that originates from the fracture mechanics and local flexibility rules. The present work exhibits the analysis of cracked beam with a machine learning model to assess the stiffness of the structure. Here Fuzzy Optimal Neural Network (FONN) is considered, in addition, the stiffness reduction technique, especially concerning thick beams, is featured with a survey of other crack models. The extricated model data are utilized to conversely recognize the cracks with the cracked beam component model through a model updating technique. The optimal Neural Network based stiffness computation utilizes a global searching procedure using Adaptive Elephant Herding Optimization (AEHO) to identify the number of cracks in various beams. From the proposed model, the attained results are compared with the existing research work, and other optimization and machine learning models.

Simulation and design of collector array units within large systems

Solar radiation data is necessary for the design of solar heating systems and used to estimate the thermal performance of solar heating plants. Compared to global irradiance, the direct beam component shows much more variability in space and time. The global radiation split into beam and diffuse radiation on collector plane is important for the evaluation of the performance of different collector types and collector field designs.

Investigation of the C3+ Auger KLL spectrum obtained in collisions of 6-15 MeV C4+ (1s2, 1s2s 3S) with gas targets

Single electron transfer to the 1s2s 3S long-lived component of the naturally occurring mixed-state(1s2, 1s2s 3S) C4+ion beam in collisions with gas targets was investigated using zero-degree Auger projectile spectroscopy at the Demokritos 5.5 MV tandem accelerator. The observed KLL Auger spectrum contains 1s2s2p 2P and 4P states resulting from direct 2p transfer to the 1s2s 3S. Higher lying (1s2s 3S)nl2,4L states produced by nl transfer (n>2) were also observed and can in principle feed the lower lying 1s2s2p2Pand 4Pstates. However, due to spin selection rules only the quartets have large enough radiative branching ratios resulting in a proposed selective feeding of only the 1s2s2p 4P state by E1 cascades, while minimally affecting the 1s2s2p 2P states. In the absence of cascades, the ratio of cross sections for 2p transfer to the 1s2s 3S state, Rm≡ σm(4P)/σm(2P), is 2 according to spin statistics. However, the 1s2ground state beam component also contributes to the production of the 1s2s2p 2P doublet states by transfer-excitation. To isolate just the 1s2s 3S transfer contribution and compute Rm, a new technique was employed requiring the recording of two KLL spectra, with the same collision energy, but each with appreciably different 1s2s 3S content, varied by stripping techniques. Our determination of Rmshows this to be >2, in agreement with spin statistics, but contrary to the expected 4P enhancement due to cascade feeding. Details of the analysis and results are discussed.

Mixed-State Ionic Beams: An Effective Tool for Collision Dynamics Investigations

The use of mixed-state ionic beams in collision dynamics investigations is examined. Using high resolution Auger projectile spectroscopy involving He-like ( 1 s 2 1 S , 1 s 2 s 3 , 1 S ) mixed-state beams, the spectrum contributions of the 1 s 2 s 3 S metastable beam component is effectively separated and clearly identified. This is performed with a technique that exploits two independent spectrum measurements under the same collision conditions, but with ions having quite different metastable fractions, judiciously selected by varying the ion beam charge-stripping conditions. Details of the technique are presented together with characteristic examples. In collisions of 4 MeV B 3 + with H 2 targets, the Auger electron spectrum of the separated 1 s 2 s 3 S boron beam component allows for a detailed analysis of the formation of the 1 s 2 s ( 3 S ) n l 2 L states by direct n l transfer. In addition, the production of hollow 2 s 2 p 1 , 3 P doubly- and 2 s 2 p 2 2 D triply-excited states, by direct excitation and transfer-excitation processes, respectively, can also be independently studied. In similar mixed-state beam collisions of 15 MeV C 4 + with H 2 , He, Ne and Ar targets, the contributions of the 1 s 2 , 1 s 2 s 3 , 1 S beam components to the formation of the 2 s 2 p 3 , 1 P states by double-excitation, 1 s → 2 p excitation and transfer-loss processes can be clearly identified, facilitating comparisons with theoretical calculations.

Mixed-State Ionic Beams: An Effective Tool for Collision Dynamics Investigations

The use of mixed-state ionic beams in collision dynamics investigations is examined. Using high resolution Auger projectile spectroscopy involving He-like ($1s^2\thinspace^1\!S, 1s2s\thinspace^{3,1}\!S$) mixed-state beams, the spectrum contributions of the $1s2s\thinspace^3\!S$ metastable beam component is effectively separated and clearly identified. This is performed with a technique that exploits two independent spectrum measurements under the same collision conditions, but with ions having quite different metastable fractions, judiciously selected by varying the ion beam charge-stripping conditions. Details of the technique are presented together with characteristic examples. In collisions of 4 MeV B$^{3+}$ with H$_2$ targets, the Auger electron spectrum of the separated $1s2s\thinspace^{3}S$ boron beam component allows for a detailed analysis of the formation of the $1s2s(^3\!S)nl \thinspace^2\!L$ states by direct $nl$ transfer. In addition, the production of hollow $2s2p\thinspace^{1,3}\!P$ doubly- and $2s2p^2\thinspace^2\!D$ triply-excited states, by direct excitation and transfer-excitation processes, respectively, can also be independently studied. In similar mixed-state beam collisions of 15 MeV C$^{4+}$ with H$_2$, He, Ne and Ar targets, the contributions of the $1s^2$, $1s2s\thinspace^{3,1}S$ beam components to the formation of the $2s2p\thinspace^{3,1}\!P$ states by double-excitation, $1s\rightarrow2p$ excitation and transfer-loss processes can be clearly identified, facilitating comparisons with theoretical calculations.

System Level Design Optimization Method for Lightweight Manufacturable Design

This paper presents a method for a system level design optimization, using currently available commercial tools. A process outlining the optimization steps to be used was created based on performing topology optimization on important components and performing a conceptual topology optimization on the entire system. Using this process, a study was performed on a ceiling structure provided by an industry partner. From the design requirements, three primary areas were targeted for design optimization, the component level optimization of the cross beam component, the component level optimization of a roof attachment bracket, and the system level of the general roof structure. This study produced a design for the ceiling structure that reduced the total mass of the system by 34%, while also reducing the amount of total components in the system by 30%.