Minimized Triple-Band Eight-Element Antenna Array for 5G Metal-frame Smartphone Applications

A multiple-input-multiple-output (MIMO) antenna array for triple-band 5G metal-frame smartphone applications is proposed in this paper. Each single antenna element consists of an S-shaped feeding strip and an L-shaped radiation strip on the metal frame. The dimension of the antenna element is only 6.5 mm × 7 mm (0.076 λ0 × 0.082 λ0, λ0 is the free-space wavelength at the frequency of 3.5 GHz). The −6 dB impedance bandwidth of the proposed eight-antenna array can cover 3.3–3.8 GHz, 4.8–5 GHz, and 5.15–5.925 GHz. The evolution design and the analysis of the optimal parameters for a single antenna element are derived to investigate the principle of the antenna. The measured total efficiency is larger than 70%. The measured isolation is better than 13 dB. The measurements of the prototype agree well with the simulation results.

Estimating Water Transport from Short-Term Vessel-Based and Long-Term Bottom-Mounted Acoustic Doppler Current Profiler Measurements in an Arctic Lagoon Connected to the Beaufort Sea

Acoustic Doppler current profilers (ADCP) are quasi-remote sensing instruments widely used in oceanography to measure velocity profiles continuously. One of the applications is the quantification of land–ocean exchange, which plays a key role in the global cycling of water, heat, and materials. This exchange mostly occurs through estuaries, lagoons, and bays. Studies on the subject thus require that observations of total volume or mass transport can be achieved. Alternatively, numerical modeling is needed for the computation of transport, which, however, also requires that the model is validated properly. Since flows across an estuary, lagoon, or bay are usually non-uniform and point measurements will not be sufficient, continuous measurements across a transect are desired but cannot be performed in the long run due to budget constraints. In this paper, we use a combination of short-term transect-based measurements from a vessel-mounted ADCP and relatively long-term point measurements from a moored ADCP at the bottom to obtain regression coefficients between the transport from the vessel-based observations and the depth-averaged velocity from the bottom-based observations. The method is applied to an Arctic lagoon by using an ADCP mounted on a buoyant platform towed by a small inflatable vessel and another ADCP mounted on a bottom deployed metal frame. The vessel-based measurements were performed continuously for nearly 5 h, which was sufficient to derive a linear regression between the datasets with an R2-value of 0.89. The regression coefficients were in turn applied to the entire time for the moored instrument measurements, which are used in the interpretation of the subtidal transport variations.

Computational Analysis of the Forces Distribution in a Metal Frame Structure Taking into Account Plastic Deformations of the Material

Постановка задачи. С целью снижения материалоемкости строительных конструкций нормативные документы рекомендуют учитывать пластические свойства стали в прочностных расчетах. Это требует развития соответствующих методов расчета с применением современного программного обеспечения. Результаты. Усовершенствована методика расчета плоского стального рамного каркаса на статическую нагрузку на основе принципа предельного равновесия с применением программно-вычислительного комплекса «ЛИРА». Исследован поэтапный характер разрушения конструкции при воздействии сверхнормативных нагрузок. Выводы. Показано, что применение пошагового метода нагружения позволяет моделировать поведение конструкции в ходе увеличения нагрузки. Проведенные исследования позволяют давать верхнюю оценку максимально возможной нагрузки, возникающей в исключительных условиях эксплуатации. Statement of the problem. In order to reduce the material consumption of building structures, in regulatory documents it is recommend that the plastic properties of steel in strength calculations are taken into account. This requires the development of appropriate calculation methods by means of modern software. Results. The method of calculating a flat steel frame structure for static load based on the principle of limiting equilibrium using the design-computational complex LIRA has been improved. The gradual nature of structural failure under the influence of excessive loads is studied. Conclusions. It is shown that the application of the step-by-step loading method makes it possible to model the behavior of the structure during an increase in load. The studies allow us to provide an upper estimation of the maximum possible load that occurs under exceptional operating conditions.

REGULATION OF STRESS-DEFORMED STATE IN COMPRESSED ELEMENTS OF STEEL FRAMES

The article is devoted to the regulation of the stress-strain state in the compressed elements of steel frames under full operating load. It is proposed to perform reinforcement of such elements with different end eccentricities of load application by rational regulation of the stress-strain state in the reinforcement elements. It is shown that the use of SDS adjustment for frame racks increases their bearing capacity and reduces deformability and welds. The new proposed technology of SDS regulation and possible constructive decisions are offered. Numerical experiment revealed high efficiency of application of the proposed solutions during the reconstruction and reinforcement of the metal frame system. The implementation of the proposed method of SDS regulation confirmed its effectiveness.

Icosahedron [Cl12]12- Templated Gigantic Gd158Co38 Nanocluster with the Largest Ln158 Core for Magnetic Cooling

The synthesis of large nano-sized cluster-molecules is a goal that synthesists and structural scientists have been pursuing, as well as a huge challenge. Herein, the largest 3d-4f metal clusters Cl12@Gd158Co38 and Br12@Gd158Co38 until now are obtained through the “multi-anions-template” strategy, with a protein-sized metal frame (ca. 4.3 × 3.6 × 3.5 nm3). Different from the mixed distribution of 3d and 4f metals and the hollow structure in the previous giant 3d-4f clusters, for the dense core-shell structure Cl12@Gd158Co38 and Br12@Gd158Co38, the Ln158 core with the highest Ln nuclearity number is induced by icosahedra-shaped templates [Cl12]12- or [Br12]12-, while 3d metals (Co) are distributed on its periphery. Their appearances point out a new structure type of non-open giant Ln-based clusters (metal number > 100) and provide an ideal model for studying the multi-level assembly of complex macromolecules. Additionally, Cl12@Gd158Co38 shows the largest magnetic entropy change (-∆Smmax = 46.95 J kg-1 K-1 under 2.0 K and ΔH = 7 T) among reported high-nuclearity 3d-4f clusters.

Containers made of composite materials for transportation and storage of aircraft engines

The description and the main structural components of the design construction of the container made of composite materials are given. There are two options for the container frame — with a composite frame and a metal frame. The use of an inert gas pressurization system of a body is described. The selection of materials for the construction of the container is substantiated, the features and properties of the developed model are considered. Keywords: container, composite materials, transportation, storage, construction. [email protected].