Free-form optimization of nanophotonic devices: from classical methods to deep learning

Nanophotonic devices have enabled microscopic control of light with an unprecedented spatial resolution by employing subwavelength optical elements that can strongly interact with incident waves. However, to date, most nanophotonic devices have been designed based on fixed-shape optical elements, and a large portion of their design potential has remained unexplored. It is only recently that free-form design schemes have been spotlighted in nanophotonics, offering routes to make a break from conventional design constraints and utilize the full design potential. In this review, we systematically overview the nascent yet rapidly growing field of free-form nanophotonic device design. We attempt to define the term “free-form” in the context of photonic device design, and survey different strategies for free-form optimization of nanophotonic devices spanning from classical methods, adjoint-based methods, to contemporary machine-learning-based approaches.

Analysis of damages and defects of the repair and operational unit of the compressor station

The need to maintain the technical condition of buildings with a significant service life determines the regularity of their inspection. The paper presents the analysis of the results of the inspection of the building of the repair and operational block of the compressor station. The analysis of the design documentation and the results of the measurement work showed that the construction is a one-story basementless building with dimensions of 54.62x18.74x5.9 m. The performed visual examination showed the presence of damages and defects of the third and fourth categories, which requires certain actions to eliminate them. Visual examination showed the need for instrumental examination. In particular, the need to determine the strength of brickwork and the strength of concrete in structures. The analysis of the results of the instrumental examination showed: the results of testing the wall masonry by the shock pulse method using the ONIKS 2.5 device showed that the compressive strength grade of silicate and ceramic bricks of the walls of the repair and maintenance block corresponds to M100, and the grade of masonry mortar is M50; The results of concrete testing by the non-destructive method of strength control in accordance with GOST 22690-88 with the DigiShmidt 2000 device showed that the class of concrete in terms of compressive strength in reinforced concrete slabs of the covering of the repair and operational block corresponds to B20, and the class of concrete in reinforced concrete beams of the covering corresponds to B25. The verification calculation showed that the strength of the reinforced concrete pavement of the repair and maintenance unit under the full design load acting at the time of the survey was ensured. The analysis showed that the technical condition of the maintenance and operation unit is of limited serviceability. The work provides recommendations for eliminating defects and damages.

A reflection on a bone tissue engineering design and commercialisation project

<p>A commercialisation project centred round a material called synthetic nacre was undertaken as a teamas part of the 2014 Masters of Advanced Technology Enterprise (MATE) programme. There were multiple goals of: examining the individual role within the group,from an engineering discipline(mechatronics), and what it means for building successful teams; finding and developing the material for a market application, in this casethe niche ofbiodegradable osteoconductive load bearing biomaterials for orthopaedic implants; andreflecting on the personalcontribution to the commercialisation processand how successful it was. The role of an engineer to solve problems was proposed and found to be partially true in this case; additionally a secondary role in communicating technical information coherently was also apparent and important to the enterprise development. An adaptive biomaterial design concept and specification for the target application was formed using the literature and extrapolating where there was no resolution or gaps in the research. The influence of mechatronics has been established on the decision making process and direction of the commercialisation project. The design process was incomplete and therefore the enterprise develop was unsuccessful as it has not been validated by going through a full design, test, evaluate cycle. The goals of the course environment and the team building approach further reinforces this belief.</p>

A reflection on a bone tissue engineering design and commercialisation project

<p>A commercialisation project centred round a material called synthetic nacre was undertaken as a teamas part of the 2014 Masters of Advanced Technology Enterprise (MATE) programme. There were multiple goals of: examining the individual role within the group,from an engineering discipline(mechatronics), and what it means for building successful teams; finding and developing the material for a market application, in this casethe niche ofbiodegradable osteoconductive load bearing biomaterials for orthopaedic implants; andreflecting on the personalcontribution to the commercialisation processand how successful it was. The role of an engineer to solve problems was proposed and found to be partially true in this case; additionally a secondary role in communicating technical information coherently was also apparent and important to the enterprise development. An adaptive biomaterial design concept and specification for the target application was formed using the literature and extrapolating where there was no resolution or gaps in the research. The influence of mechatronics has been established on the decision making process and direction of the commercialisation project. The design process was incomplete and therefore the enterprise develop was unsuccessful as it has not been validated by going through a full design, test, evaluate cycle. The goals of the course environment and the team building approach further reinforces this belief.</p>

Compact Broadband Microstrip Triangular Antennas Fed By Folded Triangular Patch for Wireless Applications

This study presents two new designs of reduced size broadband microstrip patch antennas for ultra-wideband (UWB) operation. A folded triangular patch’s feeding technique, V-shaped slot, half V-shaped slot and shorting pins are employed to design the suggested antennas. The shorting pins are applied at the edge of structures to miniaturize the size of the patches. The suggested design with the V-shaped slot provides the measured impedance bandwidth (S11˂-10 dB) of 3.91-12 GHz (101.7%) for broadband application. In the suggested design with the V-shaped slot, the wide bandwidth with an acceptable size reduction is achieved. By introducing a suggested half design with the half V-shaped slot, the impedance bandwidth of the proposed half structure is improved from 4 to 17.22 GHz. The half design includes a measured impedance bandwidth of 124.6% with reduced size of more than 93% compared to the corresponding full design and an enhanced measured bandwidth of 23%. The obtained radiation and impedance results show that the suggested designs are applicable for wideband operation. Besides, the effects of some basic concepts and surface currents on the suggested structures are investigated to explain their broadband performance.

Design, Simulation and Analysis of the Propulsion and Control System for an Electric Vehicle

The problems of global warming, a decrease of the available natural resources and many other problems in the world that happen recently become the major cause for increasing the demand for a new type of vehicle. That vehicle can be an environmental friend and so that a new generation of vehicles has been invented and tried to solve and avoid many problems. In this chapter, the proposed system is called the Multi-Converter/Multi-Machine system (MCMMS) which consists of two Synchronous Reluctance Motor (SynRM) that drive the two rear wheels of Pure Electric Vehicle (PEV). The SynRM speed and torque are controlled by using three different strategies of the PID controller. The PSO algorithm has been used as an optimization technique to find the optimal PID parameter to enhance the drive system performance of the PEV. In this system, the space vector pulse width modulation inverter for voltage source (VS-SVPWMI) has been employed to convert the DC battery voltage to three-phase AC voltage that feeds the SynRM motor in the PEV. The linear speed of the vehicle is controlled by an Electronic Differential Controller (EDC) which gives the reference speed for each driving wheel which depends on the driver reference speed and the steering angle. The specified driving route topology with three different road cases has been applied to acting and show the resistive forces that affected on the PEV during its moving on the road. In addition, to test the efficiency and stability of the PEV on the roads. Hence, this chapter has a full design, simulation and several comparison results for the propulsion electric vehicle system and it has tested implemented in the Matlab/Simulink environment version R2020a.

A Realization of Stabilizing the Output Light Power from a Laser Diode: A Practical Approach

Semiconductor Laser Diodes (LDs) are known for their sensitivity to variation in ambient temperature. With the rise in case temperature the threshold current of the LD increases, causing the output light power to deteriorate drastically. Therefore, it is necessary to stabilize the temperature of the diode. Various approaches could be adopted in this regard. In this paper, an active cooling approach using the temperature compensation technique has been followed and presented in the form of a full design of the circuit according to the various datasheet parameters of the LD and other components. As a result of temperature stabilization, a significant improvement in the output light power stabilization was observed and the results are presented.

Design A Multi Biometric System for Safe Access to Buildings

Designing a multi-biometric system for safe access to buildings is a very critical process because this system will act as an alternative of humans in observation, and must make smart decisions to protect the building from any intruder depending on the biometric information of the entering persons. In this paper a full design of a proposed multi-biometric system will be presented, two sensors are used (Visible and Thermal). the proposed system consists of several subsystems The first is the construction of a database that contains all the photos and information about each person who belongs to the building, the central system using visible and thermal cameras, and the peripheral system using visible cameras only. The central system is capable of remotely identifying and ensure of the health condition (Temperature, Heart Rate, Respiration Rate) of each entering person which is a very important process, especially with the COVID-19 pandemic. The peripheral system monitors any suspicious issue like crowed or walking outside allowed lines.

Design of the MIDES plant

This chapter presents the full design of two microbial desalination cells (MDCs) at pilot-plant scale from the MIDES project. The final MDC pilot unit design was based on the knowledge gained through up scaling of the MDC from lab- to prepilot scale. The MDC pilot plant consists of one stack of 15 MDC pilot units with 0.4 m2 electrode area. This chapter also presents the piping and instrumentation diagram (P&ID) and layout of the MDC pilot plant. The MIDES pilot plants are comprised of an MDC pilot plant housed in a 40-ft container with the rest of the peripheral elements. Finally, this chapter presents the improvement made from the first to the second MDC stack in terms of stability and the chemical compatibility of the end plates.