An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Purpose The purpose of this paper is to provide information about the long-term ex-post impacts of Vision 2023 technology foresight (TF) on the defense sector and to identify critical success factors (CSFs) of impactful foresight. Design/methodology/approach In the present research, a theory-based evaluation approach was adopted with the logic-model of defense TF to identify the intended outcomes, impacts and leading mechanisms. The impact assessment framework developed by Johnston, R. (2012) was adopted to identify (un)intended impacts and possible measures. Findings TF had some effects on technological developments, foresight capacity and capability and skills on the sector. The overall impact was assessed at the “some contribution” level with 2.9 out of 5.0 points. It contributed to the development of science technology and innovation (STI) policies and research and development programs, awareness-raising in STI, increase in cooperation between government-university-industry and the development of foresight culture. However, the impacts were more visible in the early years of TF. Additionally, country/sector-specific CSFs were identified. In consequence, it was proposed to measure the maturity of strategic technologies with technology readiness level as a tangible indicator. Originality/value According to the authors, this is the first study to assess the long-term ex-post impact of TF in defense. An instrument was developed to assess TF’s contribution to impact measures. The constructs and weights of the instrument differentiated from the adopted framework/schema reflecting the national/sectoral context of TF. Additionally, the study revealed country/sector-specific CSFs and new tangible impact measures.
The motion of plasma density enhancements (barium clouds) artificially introduced into the postsunset equatorial F region is investigated with a two‐dimensional model incorporating flux tube integrated quantities. The temporal development of the ionosphere, in which the density perturbations are imbedded, is derived from a one‐dimensional set of relations modeling plasma transport and the vertical electric field from initial conditions and a prescribed variation of the horizontal electric field as a function of time. The calculations show that the strong horizontal shear flows existing at the nighttime F region ledge (where the perturbations were placed) reduce the growth of polarization fields associated with the enhancements and adjacent relative depletions of plasma for weak perturbations. The reason is that the perturbations develop a strong tilt with respect to the horizontal. More massive density perturbations lead to stronger drop velocities with respect to the rising ambient plasma. At a later time they develop secondary horizontal density perturbations on the side unstable to E × B drift instability due to the motion of neutral constituents. When rising “bubbles” of low density are produced, they (1) form on the steepened eastward side of the enhancement perturbation, (2) have a width comparable to the scale size of the enhancement perturbation, and (3) are most easily produced when the enhancement perturbation size is comparable to the scale height of the integrated density. These simulations show why experimental efforts of initiating rising bubbles and equatorial spread F have not been successful. The experiments require larger‐scale and stronger density perturbations than what can be achieved with conventional sounding rocket releases of barium vapors.
Purpose Technologies are constantly developed to address new demands and provide further opportunities. Owing to a number of potential application areas of nanotechnologies within this sector, the purpose of this study is to take defense as a case and propose a strategic roadmap for the use of nanotechnologies in the Turkish Defense Industry. Design/methodology/approach The study presented in this paper uses a bibliometric analysis of the most cited publications in the past decade with the aim of identifying the trends in the development of nanotechnology. Interviews were carried out with experts based on the featured words of bibliometric analysis (nanoparticles, nanostructure, self-assembly, drug delivery, graphene, etc.) to reveal the commercialization time of nanotechnology products and applications. After that, a survey was carried out with engineers for determining the possible emergence time of nanotechnology applications and/or products used in military up to year 2035. Finally, a roadmap was created based on the obtained data from bibliometric analysis, interviews and survey results. Findings Nanotechnology roadmap was prepared, one which would contribute to the preparation of the defense industry for the future and help in keeping up with technological developments. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Interviews and surveys have limitation with the bounded rationality of corresponders. Practical implications The paper proposed a nanotechnology roadmap for the defense sector with a data-led foresight practice. Originality/value Performing such a study is considered to be crucial for the armies of developed and developing countries, so that the military sector also avails benefits from this revolutionary technology. Quantitative and qualitative methods were mixed for developing the roadmap.
Summary form only given. We developed 1d3v Particle in Cell/Monte Carlo Collision (PIC/MCC) numerical code for the Radio-Frequency (RF) capacitive glow discharge. This method includes the solution of the Lorentz force equation for the motion of super particles and the Poisson equation for the electric field. Collisions between the particles are modeled with the Monte Carlo method. In this process, the elastic and charge exchange collisions between the ion-neutral pairs, as well as the elastic, excitation and ionization collisions between the electron-neutral pairs are taken into account. Test calculations were carried out for the plasma of RF discharge. Numerical code was validated by comparison with the published simulation results. Parallelization of this code was performed and the efficiency in time was studied. This efficiency was also analyzed according to increasing number of cores in a cluster.
A plasma antenna, diverging from the conventional metal conductors, operates using noble gases. This study encompassed simulations and experiments on both dipole plasma antennas and dipole metal antennas operating within the very high frequency (VHF) band. The plasma dipole antenna configuration comprises two specially designed plasma sources positioned as the arms of a standard metal dipole. Initially, simulations were conducted to determine the plasma parameters and calculate the dielectric permittivity. The gas-filled plasma tube was energized by directly connecting it to the electrodes via an ac power supply (10 kV, 30 mA). Experimental and simulated results for return loss, gain, and impedance were presented for both the dipole plasma antenna and the dipole metal antenna. The findings indicate superior impedance, voltage standing wave ratio (VSWR), and gain characteristics in the dipole plasma antenna compared with its metal counterpart. In addition, the rapid on/off functionality of plasma antennas, unachievable with metal antennas, renders them particularly appealing for stealth applications like radar systems.
By using Cs atomic sensor, the differences between the measurement results of double radiooptical resonance (DROR) and the ratio of Doppler amplitude to DROR signal (Doppler/DROR) for the far-field microwave magnetic field were illustrated experimentally. The effects of laser power and atomic sensor temperature to the DROR and Doppler/DROR ratio were investigated. At constant laser power, Cs atomic cell temperature and microwave magnetic field strength, the maximum deviations for DROR and Doppler/DROR ratio were calculated over time. The fluctuation of the Doppler/DROR ratio measurement results was calculated approximately as 0.5 dB in 24-h measurement time interval. On the other hand, the fluctuation of the measured DROR values was calculated as 0.9 dB in the same time interval. As a consequence, Doppler/DROR ratio measurements yield better and repeatable results by comparison with DROR measurements.
This study demonstrated our prototyped Micro Electro Mechanical System (MEMS) electron emitter which is a nc-Si (nanocrystalline silicon) ballistic electron emitter array integrated with an active-matrix driving LSI for high-speed Massively Parallel Electron Beam Direct Writing (MPEBDW) system. The MPEBDW system consists of the multi-column, and each column provides multi-beam. Each column consists of emitter array, a MEMS condenser lens array, an MEMS anode array, a stigmator, three-stage deflectors to align and to scan the multi beams, and a reduction lens as an objective lens. The emitter array generates 100x100 electron beams with binary patterns. The pattern exposed on a target is stored in one of the duplicate memories in the active matrix LSI. After the emission, each electron beam is condensed into narrow beam in parallel to the axis of electron optics of the system with the condenser lens array. The electrons of the beams are accelerated and pass through the anode array. The stigmator and deflectors make fine adjustments to the position of the beams. The reduction lens in the final stage focuses all parallel beams on the surface of the target wafer. The lens reduces the electron image to 1%-10% in size. Electron source in this system is nc-Si ballistic surface electron emitter. The characteristics of the emitter of 1:1 projection of e-beam have been demonstrated in our previous work. We developed a Crestec Surface Electron emission Lithography (CSEL) for mass production of semiconductor devices. CSEL system is 1:1 electron projection lithography using surface electron emitter. In first report, we confirmed that a test bench of CSEL resolved below 30 nm pattern over 0.2 um square area. Practical resolution of the system is limited by the chromatic aberration. We also demonstrated the CSEL system exposed deep sub-micron pattern over full-field for practical use. As an interim report of our development of MPEBDW system, we evaluated characteristics of the emitter array integrated with an active-matrix driving LSI on the CSEL system in this study. The results of its performance as an electron source for massively parallel operation are described. The CSEL as an experimental set consisted of the emitter array and a stage as a collector electrode that is parallel to the surface of the emitters. An accelerating voltage of about -5 kV was applied to the surface of the emitter array with respect to the collector. The target wafer and the emitter array were set between two magnets. The two magnets generated vertical magnetic field of 0.5 T to the surface of the target wafer. A gap between the emitter array and the target wafer was adjusted to a focus length depending on electron trajectories in the electromagnetic field in the system. The emitter array projected 100x100 electron beams with binary patterns and a dots image of its original size on the target wafer. The certain array was examined in order to evaluate the property of the e-beam exposure.
Abstract. and n In step index fibers, core and cladding refractive index respectively n 1 2 have small difference from each other and they are independent from radius. There are a lot of methods to solution of the electromagnetic wave which propagate in a step index fiber. However, most of them have large matrix equations in their solution. This means that a lot of time is spend to solution of wave equation. Therefore, different methods should be used for wave equation solution. In this study, a series solution was used for solutions in step-index fibers. Some drawings were obtained from solutions by using a computer program and they were compared with the literature. The results are consistent each other. In this method, computation time is very low. Furthermore, both electric and magnetic fields can be computed by using this method. These are the important reasons to prefer this method. Keywords: Step-Index Fibers, Wave Equation Solutions, Series Solutions Much kind of optical fibers are used for optical waveguides. Some of them are very suitable for calculation in the theory and for application in the practice. A cylindrical optical waveguide is used often in calculation because of its structure. In this structure, there are two different region; core and cladding. In the core of the fiber, refractive index is called
