Enhanced catalyst performance using integrated structured functionalities

A compact, single-layer, wideband, tilted-beam microstrip antenna with customized tilt angle is presented. The antenna is comprised by one subwavelength driven patch and several subwavelength parasitic patches. The tilt angle of the antenna is determined by the index distributions of those subwavelength patches. The detailed index-modulation principle is developed from the generalized law of refraction, wherein the reflection phase is mapped to the index by utilizing the equivalent transmission-line theory and the transverse resonance technique. As a result, the tilt angle could be customized by allocating patch cells following specific index distributions. On top of that, as a new degree of freedom in design, one could choose subwavelength patches with low dispersion characteristics as unit cells to further enhance the operational bandwidth and improve the stability of radiation pattern. For demonstration, two types of I-shaped patch units with different dispersion characteristics have been utilized to configure tilted-beam antennas that follow the same index distributions. In addition, the effectiveness of the developed tilted-beam antenna for array application has been proven. Experiments have been carried out to verify their performance.

Laser welding application for car body manufacturing has many advantages in the stiffness and the lightness of vehicle, the productivity of assembly line, and the degree of freedom in design. This presentation will express the innovation of car body manufacturing including parameter optimization, process modeling, and system integration. In this application the investment for systems was cut down dramatically by real time switching over the laser path between two welding stations. Points of technical discussion are as follows: optimization of parameters such as laser power, robot speed and trajectory, compact and useful design of jig & fixture to assure welding quality for 3 sheet-layer zinc-coated steel, system integration between 4kW Nd:YAG laser device and the other systems, on-line real time welding quality monitoring system, perfect safety standards for high power laser, minimization of consumption costs such as arc lamp, protective glass for optic, etc.Laser welding has found a place on Hyundai’s production plant in conjunction with the startup of mass production of new sports car, and this production system is the result of a collaboration of its engineers. Outer side sheets are joined to inner side sheets by 122 stitch welds totally. And the length is about 2.4meter.Laser welding application for car body manufacturing has many advantages in the stiffness and the lightness of vehicle, the productivity of assembly line, and the degree of freedom in design. This presentation will express the innovation of car body manufacturing including parameter optimization, process modeling, and system integration. In this application the investment for systems was cut down dramatically by real time switching over the laser path between two welding stations. Points of technical discussion are as follows: optimization of parameters such as laser power, robot speed and trajectory, compact and useful design of jig & fixture to assure welding quality for 3 sheet-layer zinc-coated steel, system integration between 4kW Nd:YAG laser device and the other systems, on-line real time welding quality monitoring system, perfect safety standards for high power laser, minimization of consumption cos...

Recent advances have made it viable to fabricate optical surfaces that are not rotationally symmetric using a new generation of diamond-turning machines. This new fabrication capability allows for surfaces whose departure from a sphere varies both radially and azimuthally in the aperture to be machined into an optical surface. This new degree of freedom allows for the design of unobscured optical systems that are truly non-symmetric by tilting the optical surfaces themselves. With this new design degree of freedom, the aperture and field of view can be pushed to yield an order of magnitude increase in aerial coverage over current production while maintaining a compact solution. In one particular case, to be presented, a diffraction limited (< λ/10), long wave infrared (LWIR), F/1.9, 10° full field of view sensor telescope is designed by introducing these non-symmetric surfaces into the optical surface prescription.

Castings and the cast metals are among the most important facets creating a foundation for modern life. [...]

Commonplace electronic appliances for consumer or industrial use are still mostly rigid or at maximum flexible entities. The flexibility of foldable units like laptops or cell phones is usually realized through flexible circuit board (FCB) interconnectors. Although flexibility allows for considerably enhanced degrees of freedom in design, it is not compatible with more complex three dimensional curvatures and dynamics thereof. In the past years a number or approaches to realize stretchable electronic circuits in order to reach beyond unidirectional bending or folding of electronics have been reported. In the frame of the European Project STELLA a particular fabrication technology for stretchable electronic systems has been developed at Technische Universitaet Berlin. This technology, termed ?stretchable circuit board? (SCB) technology, is derived from conventional printed circuit board manufacturing. Stretchability of the boards is enabled by (i) using polyurethane instead of FR4 or polyimide as a carrier material of the copper structures and (ii) a meandering design of the Cu interconnects between commercial (rigid) electronic components. Such boards can be (once) extended by up to 300% before fracture of the Cu interconnections. For repeated elongation/relaxation cycles elongations with a few percent are allowable in order reach high cycle numbers. Electronic components are assembled after local application of a solder mask and surface finish for solderability. The electronic interconnection is established using a low temperature solder alloy (SnBi, Tm=142?C). For protection and enhanced system robustness all components are subsequently encapsulated within a polyurethane capping. Systems thus realized can be readily attached to different kinds of surfaces. Most interesting for various application cases is the easy attachment to textile substrates by a simple lamination process. The field use case studies of stretchable systems in the frame of the STELLA are mostly sensor applications in the field of medical electronics like a breathing frequency monitor for babies, a shoe insole pressure sensor for diabetes patients, or a band aid inlay to measure pressure and humidity of an acute wound when pressure therapy is applied. The latter application will be described in more detail since different aspects of bio-medical applications can be explained with this example. Another emerging field of applications is textile electronics, where it has been proven, that stretchable electronics can serve a versatile building blocks for complex electronic systems integrated in textiles.

With recent advances in robustness and design predictability of additive manufacturing (AM), this production method has taken its first steps towards implementation in heavy duty industrial applications such as gas turbines and heat exchangers. Among the benefits of using AM, the most important may be the significant higher degree of freedom in design than when using conventional manufacturing methods. In order to take advantage of these new possible solutions and to consider the surface roughness that arises from AM, it is necessary to have reliable correlations for pressure losses and heat transfer. In this study, the thermal performance for additively manufactured circular channels in Inconel 939 using the Selective Laser Melting (SLM) process are experimentally investigated.

Process window for electron beam melting of Ti-6Al-4V

Ferrofluids have been used in development of active dampers due to their controllable magnetic and mechanical properties. However, design and control of these actuators are far from exhausted. The fluid nature of volumetric energy converters using ferrofluids provides additional degrees of freedom in design and operation, yet numerical analysis of such devices includes inherent multi-physics computations that can be complex. Control of a three-dimensional motion can result in substantial reduction in cost and design of electro mechanic actuators. In this paper, a ferrofluid valve is proposed. Ferrofluid is used as an actuator to open and close water flow through a channel. By changing the distribution of ferrofluid, the cross-section area of the open passage in the flow channel is controlled. To reduce the deterioration of ferrofluid in the presence of water, the ferrofluid and the controlled flow are separated by a nitrile rubber film. By varying the strength of magnetic field, the ferrofluid valve can be fully closed and opened. A multi-physics numerical simulation of the valve has been carried out to determine the opening and closing time of the valve, maximum cut off flow rate, pressure drop and resolution. The valve closing time is simulated to be 125ms in a 4 inches by 2 inches prototype. This prototype has been built to validate the simulation results.

Although we usually hope a system to be fully-actuated, unfully system often occur in practice, of which under actuated second-order systems are rather common in various applications, such as mechanical systems, robotics control, aircraft design, etc. In this paper, a direct parametric approach is proposed, solving the control problem of a class of under-actuated second-order system rather completely. According to the method in this paper, under proper assumptions, the under-actuated second-order nonlinear systems can actually be converted into a constant linear one satisfying desired eigenstructure. The method also further provides all the degrees of freedom in design which can be utilized to achieve other desired control performance. The solution of the problem is based on the solution to a type of second-order Sylvester matrix equations. Besides, the numerical example also shows the efficiency of the method.

In the design process of electrical machines – especially those with challenging performance requirements like traction motors – an individual adaption of the number of turns per phase plays an important role. Choosing a delta-connected winding instead of a Y-connection gives an additional degree of freedom in design. This can be of special importance in case of hairpin windings with their tightly restricted choice of the number of conductors per slot, as it allows to find a better match of flux, rated speed, and given voltage level. Although delta-connected windings are common in low voltage industrial applications, they are still underrepresented in traction applications. This chapter presents the most suitable design options for delta-connected PM synchronous machines and discusses their performance and efficiency in traction applications. Moreover, a new calculation method for a skewed rotor is presented. Instead of FEM calculations of several rotor slices, just one slice needs to be calculated by FEM. The flux density in all other slices is then derived from this result analytically.

Comparing Constrained Controllers for Nonlinear Hydraulic Plant Using Matlab Interface

The article presents SOLID as a system of constructive constraints that disciplines the degrees of freedom in design and transforms the evolution of software systems into a controlled process. It explains the relationship of the principles with the foundations of object-oriented programming, design patterns, and architectural styles. Non-obvious effects are examined, including premature abstractions under OCP, hidden configuration coupling under DIP/DI, class explosion and responsibility fragmentation under SRP/ISP, and semantic violations of LSP that are not captured by type signatures. An operational approach to decision validation is proposed through metrics, contract-based tests, and threshold controls for introducing abstractions, along with practical decision-making protocols.

SummaryThis paper presents a new observer‐based controller design method for Lipschitz nonlinear systems with uncertain parameters and ‐bounded disturbance inputs. In the presence of uncertain parameters, the separation principle is not applicable even in the case of linear time invariant systems. A state of the art review for uncertain linear systems is first presented to describe the shortcomings and conservatism of existing results for this problem. Then a new LMI‐based design technique is developed to solve the problem for both linear and Lipschitz nonlinear systems. The features of the new technique are the use of a new matrix decomposition, the allowance of additional degrees of freedom in design of the observer and controller feedback gains, the elimination of any need to use equality constraints, the allowance of uncertainty in the input matrix and the encompassing of all previous results under one framework. An extensive portfolio of numerical case studies is presented to illustrate the superiority of the developed design technique to existing results for linear systems from literature and to illustrate application to Lipschitz nonlinear systems. Copyright © 2016 John Wiley &amp; Sons, Ltd.

We propose a wide-angle, polarization independent and fabrication-tolerant perfect absorber, which is based on a one-dimensional stacked array consisted of vertically cascaded two pairs of metal-dielectric bilayers. The results show that the absorption peaks are over 99% at the wavelength of 5.25 μm for different polarization angles, and remain very high within wide ranges of incident and azimuthal angles. We attribute those excellent performances to the excitation of the magnetic resonance (MR) and the guided mode resonance (GMR) for the TM and TE polarization, respectively, and are further expounded by the inductor-capacitor (LC) circuit model and the eigen equation of the GMR, respectively. More importantly, this one-dimensional absorber is very robust to the spacing distance between the neighboring stacks and the metallic strip thickness, which releases degrees of freedom in design and makes the absorber extremely flexible and simple in fabrication, thus it can be a good candidate for many fascinating applications.

This dissertation investigates the application of additive manufacturing to novel microwave components, including a dielectric-loaded antenna, an antenna solution for intra-chip wireless interconnects, an all-dielectric wave-bending structure for Ka-band and a compact multiband antenna for mobile device applications. First, a novel methodology is proposed to control antenna radiation pattern based on 3D printing of specially-designed dielectric material, which realizes spatially-dependent dielectric constants around the antenna. As a proof of concept, we design a quarter-wavelength monopole antenna surrounded by a 3D-printed polymer structure with an optimized dielectric property distribution. Unlike the conventional donut-shaped pattern of a quarter-wavelength monopole antenna, one-beam and multiple-beam patterns are obtained using a genetic-algorithm-based optimization. Different dielectric constant spatial distributions are realized by changing the ratio of the dielectric to air at the unit cell level in the entire antenna volume. A two-beam monopole prototype is designed, fabricated and tested. Second, we introduce a novel antenna design enabled by 3D printing technology for future wireless intra-chip interconnects with applications to multicore architectures and system-on-chips (SoCs). In the proposed design, vertical quarter-wavelength monopoles at 160 GHz on a ground plane are used to avoid low antenna radiation efficiency caused by the silicon substrate. The monopoles are surrounded by a specially-designed dielectric distribution. This additional degree of freedom in design enabled by 3D printing technology is used to tailor wave propagation path. Simulation results show that the proposed dielectric loading approach improves the desired link gain by 8-15 dB and reduces the undesired link gain by 9-23 dB from 155 to 165 GHz. As a proof-of-concept, a 60 GHz prototype is designed, fabricated and characterized. The measurements match the simulation results and demonstrate 10 - 18 dB improvement of the desired link gain and 10 - 30 dB reduction in the crosstalk from 55 to 61 GHz. The demonstrated path loss of the desired link at a distance of 17 mm is only 15 dB, which is over 10 dB better than the previously reported work. Moreover, based on liquid crystal material, we can achieve reconfigurable antennas for intra-chip wireless interconnects. Third, a 90° wave-bending structure at Ka-band (26.5 - 40 GHz) based on 3D-printed metamaterial is designed, fabricated and measured. The wave-bending effect is realized through a spatial distribution of varied effective dielectric constants. Based on the effective medium theory, different effective dielectric constants are accomplished by special, 3D-printable unit cells, which allow different ratios of dielectric to air at the unit cell level. In contrast to traditional, metallic-structure-included metamaterial designs, the reported wave-bending structure here is all dielectric and implemented by the polymer-jetting technique, which features rapid, low-cost and convenient prototyping. Lastly, a compact multi-band antenna compatible with a metallic packaging for mobile devices is proposed. The antenna covers band-1 698 - 787 MHz and band-2 1710 - 2155 MHz, enabling LTE 2 / LTE 4 / LTE 12 / LTE 13 / GSM1900 applications. The current distribution shows that the quarter-wavelength, half-wavelength and one-wavelength modes together contribute to the radiation in both bands. A four-element LC circuit is utilized for antenna bandwidth matching. The antenna is fabricated and measured. Close agreement between the measurement results and simulation results is observed.