Polo-Lopez, Lucas, Masa-Campos, Jose L., and Ruiz-Cruz, Jorge A.
International Journal of RF and Microwave Computer-Aided Engineering. Dec 2019, Vol. 29 Issue 12, n/a
Satellite communications, Antennas (Electronics) -- Design and construction, Waveguides -- Design and construction, Sintering, 3D printing, and Computer-aided design
Keywords: additive manufacturing; fused filament fabrication; phase shifter; reconfigurable; selective laser sintering; waveguide Abstract This work presents the design and manufacturing of a K-band reconfigurable phase shifter completely implemented in waveguide technology for reduced insertion loss, good matching, and large phase shifting range. The device is based on the combination of a short slot coupler and two tunable reactive loads implemented as a section of short-circuited waveguide where an adjustable metallic post is inserted. Three prototypes of this design have been manufactured using different techniques (conventional computer numerical control machining, a low-cost fused filament fabrication technique and direct metal laser sintering) in order to assess its performance for different applications. The prototypes have been characterized experimentally and the achieved results are evaluated and compared. The proposed phase shifter, since it is fully developed in waveguide technology, eliminates the need of adding transitions to planar structures in order to integrate lumped components like pin diodes or varactors. Therefore, this device has a great potential in high-power beam steering phased arrays. Biographical information: Lucas Polo-Lopez received the BSc and MSc degrees in Telecommunication Engineering from the Universidad Autonoma de Madrid, Madrid, Spain in 2014 and 2016, respectively. Since 2015 he has been with the Radiofrequency Circuits, Antennas and Systems (RFCAS) group of this same university, where he works toward the PhD degree. His current research interests include the computer-aided design of horn antennas and passive waveguide devices, as well as the application of additive manufacturing techniques to the construction of waveguide devices. Jose L. Masa-Campos received the Master degree in 1999 and the PhD Degree in 2006, from the Universidad Politecnica de Madrid, Spain. From 1999 to 2003 he developed his professional activity in the R&D department of the company RYMSA with the design of base station antennas for mobile communications and satellite antennas. From 2002 to 2003 he directed the R&D department of RYMSA. From 2003 to 2007, he worked as Researcher for Universidad Politecnica de Madrid, and in 2005 he joined to Universidad Autonoma de Madrid as Associate Professor in the Radiofrequency Circuits, Antennas and Systems (RFCAS) group. His main current research interests are in active and passive planar array antennas. Jorge A. Ruiz-Cruz received the Ingeniero de Telecomunicacion degree and the PhD degree from the Universidad Politecnica de Madrid, Madrid, Spain, in 1999 and 2005, respectively. Since 2006, he has been with the Universidad Autonoma de Madrid, Madrid, where he became an Associate Professor in 2009. His current research interests include the computer-aided design of microwave passive devices and circuits (filters, multiplexers, and orthomodes). Byline: Lucas Polo-Lopez,Jose L. Masa-Campos,Jorge A. Ruiz-Cruz
This article presents a novel methodology to design swash plate type axial piston machines based on computationally based approach. The methodology focuses on the design of the main lubricating interfaces present in a swash plate type unit: the cylinder block/valve plate, the piston/cylinder, and the slipper/swash plate interface. These interfaces determine the behavior of the machine in term of energy efficiency and durability. The proposed method couples for the first time the numerical models developed at the authors’ research center for each separated tribological interface in a single optimization framework. The paper details the optimization procedure, the geometry, and material considered for each part. A physical prototype was also built and tested from the optimal results found from the numerical model. Tests were performed at the authors’ lab, confirming the validity of the proposed method.
Byline: Mohamed Farid Shehab, Nabila Mohammed Abdel Hamid, Nevien Abdullatif Askar, Ahmed Mokhtar Elmardenly Keywords: CAD-CAM, electron beam melting; immediate mandibular reconstruction; patient-specific titanium mesh; rapid prototyping Abstract Background Immediate mandibular reconstruction was performed using a patient-specific titanium mesh tray fabricated by electron beam melting (EBM) /rapid prototyping techniques. Methods Patient-specific titanium trays were virtually designed and fabricated using EBM technology/rapid prototyping for patients requiring mandibular resection and immediate reconstruction using an iliac crest bone graft. Dental implants were placed in the grafted sites and the patients received prosthetic rehabilitation with a follow-up of one year. Clinical data, postoperative bone formation and complications were evaluated. Results A symmetric appearance of facial contours was achieved. The titanium tray incorporated the particulate iliac crest bone graft that provided significant bone formation (mean 18.97 [+ or -] 1.45 mm) and predictable results. Stability of the dental implants was achieved. Conclusion The patient-specific titanium meshes and immediate particulate autogenous bone graft showed satisfactory clinical and surgical results in improving patients' quality of life and decreasing the overall treatment time with adequate functional rehabilitation.
Dorozynski, Przemyslaw, Jamroz, Witold, Wegiarz, Wladyslaw P., Kulinowski, Wojciech, Zaborowski, Mateusz, and Kulinowski, Piotr
Dissolution Technologies. Nov 2018, Vol. 25 Issue 4, p48, 6 p.
3D printing and Testing equipment
INTRODUCTION The number of studies concerning application of three dimensional (3D) printing techniques in pharmaceutical technology has grown continuously since 2005, but the main interest in application of these techniques [...] Purpose of the research was to assess feasibility of fused deposition techniques (3D printing) for development of analytical equipment dedicated for specific dosage forms and for nonstandard applications. Dissolution profiles as well as 3D magnetic resonance imaging (MRI) of the buccal tablets during hydration in dissolution medium were analyzed. The principal result of the study was the first working example of rapid 3D prototyping of dedicated, MRI-compatible dissolution equipment for mucoadhesive buccal tablets. Rapid prototyping techniques were found to be a fast, inexpensive way to develop a dedicated dissolution testing setup. KEYWORDS: additive manufacturing, 3D printing, solid free-form fabrication, buccal bioadhesive tablets, 3D ultrashort echo time magnetic resonance imaging (3D UTE MRI), pharmaceutical dissolution testing equipment
Ferrari, A., Novara, C., Paolucci, E., Vento, O., Violante, M., and Zhang, T.
Applied Energy, 2018, 232, C, 358.
Fuel injection system, Diesel engine, Injected mass control, and Rapid prototyping hardware
A closed-loop strategy that is capable of controlling the fuel injected mass in the combustion chamber of a Common Rail diesel engine has been set up. The pressure time histories measured along the rail-to-injector pipe have been used to evaluate the instantaneous mass flow-rate entering the injector. This flow-rate has then been integrated between two time instants, and the thus calculated fuel mass has resulted to correlate well with the injected mass.
András Poppe, Gábor Farkas, Lajos Gaál, Gusztáv Hantos, János Hegedüs, and Márta Rencz
Energies, 2019, 12, 10, 1.
light emitting diodes, power LEDs, multi-domain modelling, and LED luminaire design
This paper presents our approaches to chip level multi-domain LED (light emitting diode) modelling, targeting luminaire design in the Industry 4.0 era, to support virtual prototyping of LED luminaires through luminaire level multi-domain simulations. The primary goal of such virtual prototypes is to predict the light output characteristics of LED luminaires under different operating conditions. The key component in such digital twins of a luminaire is an appropriate multi-domain model for packaged LED devices that captures the electrical, thermal, and light output characteristics and their mutual dependence simultaneously and consistently. We developed two such models with this goal in mind that are presented in detail in this paper. The first model is a semi analytical, quasi black-box model that can be implemented on the basis of the built-in diode models of spice-like circuit simulators and a few added controlled sources. Our second presented model is derived from the physics of the operation of today’s power LEDs realized with multiple quantum well heterojunction structures. Both models have been implemented in the form of visual basic macros as well as circuit models suitable for usual spice circuit simulators. The primary test bench for the two circuit models was an LTspice simulation environment. Then, to support the design of different demonstrator luminaires of the Delphi4LED project, a spreadsheet application was developed, which ensured seamless integration of the two models with additional models representing the LED chips’ thermal environment in a luminaire. The usability of our proposed models is demonstrated by real design case studies during which simulated light output characteristics (such as hot lumens) were confirmed by luminaire level physical tests.
Abstract This paper describes a Grid-like Material Transportation Network (GMTN) in which several heterogeneous means of transportation (Automated Guided Vehicles (AGVs), hoists, lifts, etc.) interact with each other via common shared workstations to provide a variety of demand-responsive material handling operations. Different material handling transport modes provide movement of workpieces between workstations along their manufacturing routes in the GMTN and they can be seen as processes realized with synergic utilization of various local periodically acting unimodal processes. The main contribution of this research is the solution of a constraint satisfaction problem addressing AGVs fleet match-up scheduling subject to GMTN and fuzzy operation time constraints. In the presented case both production rate (production takt) and operations execution time are described by imprecise (fuzzy) data. In other words, the research’s objective concerns assessing grid-like networks of periodically acting local transportation modes from the perspective of possible mass-customized oriented requirements imposed on scheduling of multimodal flows of jobs assigned to certain technological routes passing through common shared workstations.