scholarly journals Functionalization of screw implants with superelastic structured Nitinol anchoring elements

2022 ◽  
Vol 21 (1) ◽  
Author(s):  
Isabell Hamann ◽  
Stefan Schleifenbaum ◽  
Christian Rotsch ◽  
Welf-Guntram Drossel ◽  
Christoph-Eckhard Heyde ◽  
...  
Keyword(s):  
Negative Influence ◽  
Test Methods ◽  
Operating Conditions ◽  
The Novel ◽  
Artificial Bone ◽  
Functional Patterns ◽  
New Type ◽  
Current Point ◽  
Surgical Conditions ◽  
Set Up

Abstract Background Demographic change is leading to an increase in the number of osteoporotic patients, so a rethink is required in implantology in order to be able to guarantee adequate anchoring stability in the bone. The functional modification of conventional standard screw implants using superelastic, structured Ti6Al4V anchoring elements promises great potential for increasing anchoring stability. Methods For this purpose, conventional screw implants were mechanically machined and extended so that structured-superelastic-positionable-Ti6Al4V anchoring elements could be used. The novel implants were investigated with three tests. The setup of the anchoring elements was investigated in CT studies in an artificial bone. In a subsequent simplified handling test, the handling of the functional samples was evaluated under surgical conditions. The anchorage stability compared to standard screw implants was investigated in a final pullout test according to ASTM F543—the international for the standard specification and test methods for metallic medical bone screws. Results The functionalization of conventional screw implants with structured superelastic Ti6Al4V anchoring elements is technically realizable. It was demonstrated that the anchoring elements can be set up in the artificial bone without any problems. The anchorage mechanism is easy to handle under operating conditions. The first simplified handling test showed that at the current point of the investigations, the anchoring elements have no negative influence on the surgical procedure (especially under the focus of screw implantation). Compared to conventional standard screws, more mechanical work is required to remove the functional patterns completely from the bone. Conclusion In summary, it was shown that conventional standard screw implants can be functionalized with Ti6Al4V-structured NiTi anchoring elements and the new type of screws are suitable for orthopedic and neurosurgical use. A first biomechanical test showed that the anchoring stability could be increased by the anchoring elements.

scholarly journals Functionalization of Screw Implants with Superelastic Structured Nitinol Anchoring Elements

2021 ◽  
Author(s):  
Isabell Hamann ◽  
Stefan Schleifenbaum ◽  
Christian Rotsch ◽  
Welf-Guntram Drossel ◽  
Christoph-Eckhard Heyde ◽  
...  
Keyword(s):  
Demographic Change ◽  
Negative Impact ◽  
Operating Conditions ◽  
Artificial Bone ◽  
Biomechanical Test ◽  
Pull Out ◽  
Functional Patterns ◽  
Surgical Conditions ◽  
Set Up ◽  
Ct Studies

Abstract Demographic change is leading to a increase in the number of osteoporotic patients, so that a rethink is required in implantology in order to be able to guarantee adequate anchoring stability in the bone. The functional modification of conventional standard screw implants by the use of superelastic, structured Ti6Al4V anchoring elements promises great potential for increasing anchoring stability. For this purpose, conventional screw implants were mechanically machined and extended so that structured-superelastic-positionable-Ti6Al4V anchoring elements could be used. The set-up of the anchoring elements was investigated in CT studies in an artificial bone. In a subsequent handling test, the handling of the function samples was evaluated under surgical conditions. The anchorage stability to standard screw implants was investigated in a final pull-out test according to "ASTM F543".The functionalization of conventional screw implants with structured superelastic Ti6Al4V anchoring elements is technically realizable. It has been demonstrated that the anchoring elements can be set up in the artificial bone without any problems. The anchorage mechanism is easy to handle under operating conditions and the anchoring elements have no negative impact on the surgical procedure. It was shown that, compared to conventional standard screws, more mechanical work is required to remove the functional patterns completely from the bone.In summary, it was shown that conventional standard screw implants can be functionalized with Ti6Al4V structured NiTi anchoring elements and are suitable for orthopedic and neurosurgical use. A first biomechanical test showed that the anchoring stability can be increased by the anchoring elements.

On the Influence of the Slot Orifice in Diesel Common Rail Nozzle

2018 ◽  
Vol 11 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Giancarlo Chiatti ◽  
Ornella Chiavola ◽  
Fulvio Palmieri ◽  
Roberto Pompei
Keyword(s):  
Cross Section ◽  
Flow Rate ◽  
Experimental Analysis ◽  
Common Rail ◽  
Spray Angle ◽  
The Novel ◽  
Hydraulic Behavior ◽  
Reference Information ◽  
Light Duty ◽  
Set Up

Background:The paper deals with a diesel common rail nozzle in which a novel orifice layout is implemented.Objective:Its influence on the nozzle mechanical-hydraulic behavior and on the spray shape transient development is experimentally investigated.Methods:In the research, a solenoid injector for light duty diesel engines is equipped with the novel nozzle prototype and tested. The prototype layout is described, pointing out the features of the nozzle orifices, in which a Slot cross-section is adopted; the investigation is accomplished extending the hydraulic tests and the spray visualizations to a reference nozzle with standard holes. The influence of the hole layout on the mechanical-hydraulic behavior of the nozzle is assessed by experimental analysis based on the rate of injection measurement, in comparison with the reference nozzle. Once the hydraulic behavior of the novel nozzle has been characterized in terms of mass flow rate, the slot influence on the spray shape is assessed analyzing the macroscopic features such as the penetration distance and the spray angle, in non evaporative conditions. The study is carried out under transient injection conditions, for different injection pressures, up to 1400 bar.Results:The results on spray characteristics also provide reference information to set up spray models suited to take the Slot orifice into account.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

Evaluation of a personal professional mentor scheme for newly qualified nurses

2021 ◽  
Vol 30 (11) ◽  
pp. 672-676
Author(s):  
Charlotte Austin ◽  
Yvonne Halpin
Keyword(s):  
Thematic Analysis ◽  
Structured Interview ◽  
Potential Outcomes ◽  
Experienced Nurses ◽  
Support Strategies ◽  
Supportive Role ◽  
New Type ◽  
Experienced Nurse ◽  
Set Up ◽  
Pastoral Support

Background: Newly qualified nurses are known to experience a range of feelings and fears in the first transitional 12 months post-qualifying, with absence and turnover among potential outcomes. Aim: To evaluate the personal professional mentor role and scheme, a new pastoral support initiative, from the perspective of participating newly qualified nurses. Methods: Newly qualified paediatric nurses (n=10), who had been assigned a personal professional mentor (an experienced nurse who worked elsewhere in their employing NHS Trust), completed a semi-structured interview. The data were analysed using thematic analysis. Findings: The personal professional mentor counteracted some aspects of transition isolation for the newly qualified nurses. They were an independent, accessible, experienced confidant and a welcome new supportive role. Conclusion: Pairing experienced nurses with newly qualified nurses provided a new type of workplace support during transition. Inexpensive to set up and run, it is an easy addition to any portfolio of support strategies.

scholarly journals A 2-D model for Intermediate Temperature Solid Oxide Fuel Cells Preliminarily Validated on Local Values

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 36 ◽  
Author(s):  
Bruno Conti ◽  
Barbara Bosio ◽  
Stephen John McPhail ◽  
Francesca Santoni ◽  
Davide Pumiglia ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Physical Parameters ◽  
Local Concentration ◽  
Oxide Fuel ◽  
Molten Carbonate ◽  
Experimental Apparatus ◽  
Set Up

Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) technology offers interesting opportunities in the panorama of a larger penetration of renewable and distributed power generation, namely high electrical efficiency at manageable scales for both remote and industrial applications. In order to optimize the performance and the operating conditions of such a pre-commercial technology, an effective synergy between experimentation and simulation is fundamental. For this purpose, starting from the SIMFC (SIMulation of Fuel Cells) code set-up and successfully validated for Molten Carbonate Fuel Cells, a new version of the code has been developed for IT-SOFCs. The new release of the code allows the calculation of the maps of the main electrical, chemical, and physical parameters on the cell plane of planar IT-SOFCs fed in co-flow. A semi-empirical kinetic formulation has been set-up, identifying the related parameters thanks to a devoted series of experiments, and integrated in SIMFC. Thanks to a multi-sampling innovative experimental apparatus the simultaneous measurement of temperature and gas composition on the cell plane was possible, so that a preliminary validation of the model on local values was carried out. A good agreement between experimental and simulated data was achieved in terms of cell voltages and local temperatures, but also, for the first time, in terms of local concentration on the cell plane, encouraging further developments. This numerical tool is proposed for a better interpretation of the phenomena occurring in IT-SOFCs and a consequential optimization of their performance.

CAD AND CAE TECHNOLOGIES OF A NOVEL PLANE SIX-BAR SWAYING MACHINE

2008 ◽  
Vol 07 (01) ◽  
pp. 65-67
Author(s):  
CHANGPING ZOU ◽  
LI DU ◽  
XIANDE HUANG
Keyword(s):  
High Pressure ◽  
Kinetic Analysis ◽  
Rotational Speed ◽  
Preliminary Analysis ◽  
Unit Weight ◽  
The Novel ◽  
Parameterized Modeling ◽  
New Type ◽  
Working Principle ◽  
Key Dimensions

A new type of six-bar swaying machine was put forward, which is an ingenious combination of plane multi-bar mechanism and high pressure oil cylinder. Preliminary analysis shows that this machine has many advantages, such as the torque produced by its unit weight, its small size, its light deadweight, etc. Thus it can be applied to situations that need swaying mechanism with low rotational speed and great torque. Firstly, the mechanism composition and working principle of the swaying machine were introduced. Secondly, parameterized modeling of the mechanism was carried out by utilizing software ADAMS. Then kinematic analysis and kinetic analysis were completed by using ADAMS. Finally, key dimensions were adjusted according to kinetic analysis. These tasks are believed to be beneficial to the development of the novel transmission.

Study on the working state of the five hundred-meter aperture spherical telescope using step-wise assignment method

2014 ◽  
Vol 229 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Yu Liu ◽  
Feng Gao
Keyword(s):  
Nonlinear Equations ◽  
Analytical Solutions ◽  
Driving Mechanism ◽  
Initial Value ◽  
Unknown Parameters ◽  
Support Structure ◽  
Assignment Method ◽  
New Type ◽  
Set Up ◽  
The Mathematical Model

The working state of the five hundred-meter aperture spherical telescope (FAST) is solved using the step-wise assignment method. In this paper, the mathematical model of the cable-net support structure of the FAST is set up by the catenary equation. There are a large number of nonlinear equations and unknown parameters of the model. The nonlinear equations are solved by using the step-wise assignment method. The method is using the analytical solutions of the cable-net equations of one working state as the initial value for the next working state, from which the analytical solutions of the nonlinear equations of the cable-net for each working state of the FAST and the tension and length of each driving cable can be obtained. The suggested algorithm is quite practically well suited to study the working state of the cable-net structures of the FAST. Also, the working state analysis result of the cable-net support structure of a reduced model of the cable-net structure reflector for the FAST is given to verify the reliability of the method. In order to show the validity of the method, comparisons with another algorithm to set the initial value are presented. This method has an important guiding significance to the further study on the control of the new type of flexible cable driving mechanism, especially the FAST.

Annihilation Lifetime Spectroscopy Using Positrons from Bremsstrahlung Production

2012 ◽  
Vol 331 ◽  
pp. 41-52 ◽  
Author(s):  
Andreas Wagner ◽  
Wolfgang Anwand ◽  
Maik Butterling ◽  
Thomas E. Cowan ◽  
Fine Fiedler ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Linear Accelerator ◽  
Electron Accelerator ◽  
Positron Annihilation Spectroscopy ◽  
Doppler Broadening ◽  
Electron Linear Accelerator ◽  
Positron Annihilation Lifetime ◽  
Electron Bremsstrahlung ◽  
New Type ◽  
Set Up

A new type of a positron annihilation lifetime spectroscopy (PALS) system has been set up at the superconducting electron accelerator ELBE [ at Helmholtz-Zentrum Dresden-Rossendorf. In contrast to existing source-based PALS systems, the approach described here makes use of an intense photon beam from electron bremsstrahlung which converts through pair production into positrons inside the sample under study. The article focusses on the production of intense bremsstrahlung using a superconducting electron linear accelerator, the production of positrons inside the sample under study, the efficient detector setup which allows for annihilation lifetime and Doppler-broadening spectroscopy simultaneously. Selected examples of positron annihilation spectroscopy are presented.

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