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Croitoru A.S.M.,Polytechnic University of Bucharest | Pacioga B.A.,National Institute for Research and Development in Mechatronics and Measurement Technique | Comsa C.S.,National Institute for Research and Development in Mechatronics and Measurement Technique
Applied Surface Science | Year: 2017

Two models of Ti6Al4V personalized femoral stems for hip replacement have been designed and laser sintered with different sizes of fenestrated architecture that mimics the natural structure of bone, ensuring postoperative bone ingrowth and increasing the elasticity of the entire structure. They were tested statically and dynamically versus a commercial femoral stem. Mechanical tests were performed in order to determine the fatigue limit using the Locati method. The tests were conducted in a thermostatic bath (37°±1°) with the implants immersed in distilled water salted solution 0.91%. For probe embedment poly-methyl methacrylate (PMMA) was used.The characteristic curves of the two personalized fenestrated implants reveal an elastic behaviour by their nonlinear appearance. After dynamic tests an inverse relationship between displacements obtained in the static tests and the fatigue limit was observed. Large fenestrations conferred the desired elasticity to the implant, but contributed to a life service reduction.The fatigue limit for both implants was much above the minimum value specified by ISO 7602: 2010, so both models can be safely used in the medical practice, leading to increased life service of implants. © 2017 Elsevier B.V.


Alexandru C.,National Institute for Research and Development in Mechatronics and Measurement Technique | Alexandru C.,University Valahia of Targoviste | Gheorghe G.I.,National Institute for Research and Development in Mechatronics and Measurement Technique | Gheorghe G.I.,University Valahia of Targoviste
AIP Conference Proceedings | Year: 2015

The mechatronic architectures is based on 3D modeling, the design of the system assembly for the parts that compose it, the equipments analysis and synthesis for the integration and the control of them.Depending on the areas for which it is modeled and designed the mechatronic system has various features related to the purpose and operation of the equipment.In the field of the product quality were carried out architectures dimensional inspection,monitoring systems architecture, and other. The system architecture is the conceptual model that defines the structure and behavior of mechatronic equipment. © 2015 AIP Publishing LLC.


Capitanu L.,Inslitute of Solid Mechanics of Romanian Academy | Badita L.L.,National Institute for Research and Development in Mechatronics and Measurement Technique | Bursuc D.C.,Military Technical Academy
Journal of the Balkan Tribological Association | Year: 2012

There have been inspected 8 modular total hip prostheses recovered, about surface state of their components joints bearing femoral head/acetabular cup. The inspection was done visually, microscopically and by surface profilometry of femoral heads. All acetabular cups were of very high density molecular polyethylene (UHMWPE). Femoral heads were Co-Cr alloy and Ti-6A1-4V coated with mono- or multi-layer thin films. This paper presents some research findings, concerning the wear behaviour of coatings, with emphasis on coverage of TiN and Co-Cr-Mo. It highlights the loss of coating adhesion, crushing them, embedding the resulting particles in acetabular cup and the failure of total hip replacements. It shows that the lack of a suitable adhesion layer - sub-layer is the main cause of failure of coatings femoral heads.


Alexandru C.,National Institute for Research and Development in Mechatronics and Measurement Technique | Sergiu D.,National Institute for Research and Development in Mechatronics and Measurement Technique
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2014

The engineering of the manufacturing processes include both conceiving, designing and execution of the systems of manufacturing and being concerned of the quality of the products that will be done with these. The quality of the manufacturing process has a very important place today for large and small enterprises. This is reflected both through the implementation of processes and technologies of production, and by using a variety of sensors of visualization and control of processes. Ensuring quality processes in auto industry involves construction of some dimensional control systems of the parts for each manufacturing technology and the equipment where these are mounted or with which interacts. The field of application of these systems of quality checking is varied from the auto field up to areas such as the pharmaceutical, food, etc. In the auto field, where the quality of the manufacturing process represents an important component, it will present solutions for applications which target dimensional control of the parts used in the construction of motor vehicles. Analyzing dimensional control systems, the mode and the procedure, for their implementation, can be optimized for various parts of the same category, or similar control operations. © 2014, Editura Cefin. All rights reserved.


Badita L.-L.,National Institute for Research and Development in Mechatronics and Measurement Technique
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2014

Hip prosthesis is a complex mechanical biotribosystem with multiple functions. Under the action of cyclic dynamic loadings, developed in a biological adversely environment, it can lose the optimal functionality during the time. As an alternative, to improve mechanical characteristics of hip prostheses, TiN thin films were deposited on cylindrical samples, made of 316L stainless steel, with hardness of 150 HV30 using pulsed laser deposition (PLD) technique. The number of applied laser pulses varied between 5000 and 20000 pulses. Adhesion strength of the layer on the substrate was evaluated by scratch tests accompanied by microscopy methods. The Atomic Force Microscopy (AFM) study offered information referring to the surface of deposited layers, before and after de scratch tests, by determining topographic parameters from ultraprecise measurements. Following these studies, and those made using Scanning Electron Microscopy (SEM) was concluded that the essential factor for increasing the hardness of femoral heads with thin layers is to provide a strong adherent coating to the substrate using PLD. This work points out that TiN protective coatings deposited by PLD technique with 20000 laser pulses can represent an alternative technology to ensure adhesion and scratch resistance of TiN coatings on femoral heads. The success condition for such coating is to provide an optimal surface roughness of femoral head that serves as substrate for TiN coating. © 2014, Editura Cefin. All right reserved.


Vaduva S.,National Institute for Research and Development in Mechatronics and Measurement Technique | Constantin A.,National Institute for Research and Development in Mechatronics and Measurement Technique
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2014

This paper deals with the mechatronic driving systems with stepper motors, used in micro-mechanics, their applications, features and the relationships between them. Also, a few types of experimental booths are discussed. © 2014, Editura Cefin. All rights reserved.


Alexandru C.O.,National Institute for Research and Development in Mechatronics and Measurement Technique | Gheorghe G.I.,National Institute for Research and Development in Mechatronics and Measurement Technique
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2014

The characterization of mechatronic systems requires knowledge of the requirements, and their tendency for the realization of the equipment and measurement tools that can be used for a long time in the conditions required by the market. The solutions and results will be presented in the following analysis of the products of the control equipment. Will be analyzed several variants of articulated arms for dimensional inspection and will be taking into account the following types of characteristics: volume measured, accuracy, precision, working time, productivity. © 2014, Editura Cefin. All right reserved.


Alexandru-Horia M.,National Institute for Research and Development in Mechatronics and Measurement Technique
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2015

Today, all modern industrial processes are automated, being controlled by complex systems with the following advantages: Eliminate the possibility of human error;- Ensure a high level of security;- Allow a good tracking and a good analysis of technological flow up to workstation level;- Allow tracking and marking, up to each part level, for finished product in hand.One of the characteristics of units designated to industrial production of heavy equipment (as is the car manufacturing) consists in developing the technological process of production over large areas, with several stations for processing, testing and installation to be inter-related, and the existence of posts with multiple concomitant technological operations.To control this process distributed automatized systems are used, in which control and execution components are distanced from central units of tracking and decision.Such schemes involve the transport of data (information and commands) in both directions (central unitexecutive) over long distances and ensure a high degree of data security and immunity to interference characteristic industrial processes.To achieve these requirements, families of industrial equipment have been developed that are aligned to various standards such as Ethernet (option for distributed industrial systems as PROFINET), RS485 (version for distributed industrial systems as PROFIBUS), CAN. © 2015, Editura Cefin. All rights reserved.


Sorin S.,National Institute for Research and Development in Mechatronics and Measurement Technique | Sergiu D.,National Institute for Research and Development in Mechatronics and Measurement Technique
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2015

Quality and performance of the MEMS systems are determined in good measure by the quality of electronic control and the interface due to specific problems of coupling between different technologies with different specific parameters. Possible solutions will be presented in the following analysis of the actuators control electronics architectures Will be analyzed several variants of actuators, particullary magnetic actuators. © 2015, Editura Cefin. All rights reserved.


Gheorghe G.I.,National Institute for Research and Development in Mechatronics and Measurement Technique | Badita L.-L.,National Institute for Research and Development in Mechatronics and Measurement Technique
Advanced Materials Research | Year: 2013

Total hip prosthesis (THP) is the most success of the 20th century in orthopaedic biomedical engineering. However due to difficult conditions within the human body its durability is generally limited to 15-16 years. THP is a bio-tribosystem, on which many mechanical, thermal, chemical and biological factors act. This paper presents the results of an analysis regarding the topography and tribological parameters of femoral heads structures before and after TiN coating. We report on the synthesis of TiN thin films on steel substrates by pulsed laser deposition (PLD) method for improving the mechanical characteristics of the structures. Adhesion resistance of the coating on the sub-layer was evaluated by scratching tests accompanied by Optical Microscopy (OM), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). As a principal result, this work points out that TiN protective coatings deposited by PLD technique with the maximum number of pulses can represent an alternative technology to ensure adhesion and scratch resistance of TiN coatings on femoral heads. © (2013) Trans Tech Publications, Switzerland.

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