Asset Administration Shell Design Methodology Using Embedded OPC Unified Architecture Server

This article captures the current trends in the development of communication interoperability and common data modelling for the integration of devices into Industry 4.0 networks. The use of open standards such as the Open Platform Communications Unified Architecture (OPC UA) or the Asset Administration Shell (AAS) concept is the only way to achieve global communication and semantic interoperability. This article presents an original methodology of AAS implementation into an embedded system, dramatically reducing system requirements. The proposed workflow of the I4.0 component creation includes a procedure for the implementation of the AAS in the OPC UA information model. This methodology was verified by creating an intelligent sensor as a specific I4.0 cyber-physical system based on the 32 bit Arm Cortex Microcontroller. The outcome is the AAS as an “Embedded Industry 4.0 Component” hosted by a minimalist hardware; this is the very first design and implementation of a device with such parameters. Compared to recent studies (which implement certain types of AAS devices), the system requirements of the proposed embedded AAS are in the order of hundreds lower. The presented novel methodology enables developers and industrial manufacturers to implement relatively simple devices (e.g., smart sensors or actuators) as I4.0 Components.

Numerical Simulation of Multiple Explosively Formed Projectile Warhead Forming Characteristics considering Various Materials

To study the influence of different liner structures and materials (copper, steel, and tungsten) on the forming characteristics of multiple explosively formed projectile (MEFP) with integrated liner and shell designs, three types of liners with different structures were designed. LS-DYNA was used for numerical simulation, and the results show that the thickness change at the center of the liner has no obvious influence on the shape of the explosively formed projectile (EFP). However, the curvature radius of the liner has a significant influence on the shape of the EFP. When the liner material is copper and the curvature radius of the liner is greater than 8 mm, the EFP shape approximates an ellipsoidal or hemispherical shape and the EFP forming speed is between 1900 m/s and 2400 m/s. When the material of the liner is steel or tungsten and the curvature radius of the liner is thicker than 8 mm, the liner is not able to form projectiles in the shape of a sphere, ellipsoid, or long rod. By comparing the forming speed from 1#EFP to 4#EFP, it can be said that MEFP with integrated liner and shell design displays a certain pressurization effect. Research results show that, for small-caliber MEFP warheads, subject to the size of the warhead, when the liner is steel or tungsten, the detonation energy generated by the limited charge does not result in the liner forming an effective EFP. However, when the liner material is selected as copper, the EFP forming shape and speed are more appropriate.

Snapshots into carbon dots formation through a combined spectroscopic approach

The design of novel carbon dots with ad hoc properties requires a comprehensive understanding of their formation mechanism, which is a complex task considering the number of variables involved, such as reaction time, structure of precursors or synthetic protocol employed. Herein, we systematically investigated the formation of carbon nanodots by tracking structural, chemical and photophysical features during the hydrothermal synthesis. We demonstrate that the formation of carbon nanodots consists of 4 consecutive steps: (i) aggregation of small organic molecules, (ii) formation of a dense core with an extended shell, (iii) collapse of the shell and (iv) aromatization of the core. In addition, we provide examples of routes towards tuning the core-shell design, synthesizing five novel carbon dots that all consist of an electron-dense core covered by an amine rich ligand shell.

In Situ Ultraviolet Polymerization Using Upconversion Nanoparticles: Nanocomposite Structures Patterned by Near Infrared Light

In this paper, we report an approach to polymerization of a nanocomposite containing UV-polymerizable organic material and inorganic, NaYbF4:Tm3+ core-based nanoparticles (NPs), which are optimized for upconversion of near infrared (NIR) to ultraviolet (UV) and blue light. Our approach is compatible with numerous existing UV-polymerizable compositions and the NaYF4: Yb, Tm3+ core-based NPs are much more stable against harsh conditions than NIR organic photo-initiators proposed earlier. The use of a core-shell design for the NPs can provide a suitable method for binding with organic constituents of the nanocomposite, while maintaining efficient NIR-to-UV/blue conversion in the NaYbF4 core. The prepared photopolymerized transparent polymer nanocomposites display upconversion photoluminescence in UV, visible and NIR ranges. We also demonstrate a successful fabrication of polymerized nanocomposite structure with millimeter/submillimeter size uniformly patterned by 980 nm irradiation of inexpensive laser diode through a photomask.

Optimizing maсhining parameters for milling pockets in waffle-grid shell structures

The paper aims to develop a procedure for calculating parameters characterizing the process of milling box-shaped parts with waffle-grid shell design made of high-strength aluminum alloys. The calculated parameters are approximated by power equations and are provided for various ranges of the technological coefficient for the bottom of the waffle-grid structure. During final machining and penetration, when setting up the advance, one should take into account the inertial properties of the linear drives of the machines, in addition to this the advance of the tool and the angle of penetration should be constrained to prevent deformation of the bottom of the pocket. Based on the results of the math simulations, the ranges of acceptable values for advance per a tooth and the penetration angle were defined. The optimal ranges for milling parameters were established, which are recommended for implementation in the manufacturing processes of machining box-shaped parts with waffle-grid shell design made of high-strength aluminum alloys. Key words: milling, shell, pocket, aluminum alloys, optimization, waffle-grid structure.