oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 181 )

2018 ( 320 )

2017 ( 296 )

2016 ( 454 )

Custom range...

Search Results: 1 - 10 of 297552 matches for " J. Marciniak "
All listed articles are free for downloading (OA Articles)
Page 1 /297552
Display every page Item
Modification of surface films on chromium-nickel-molybdenum steel implants used in orthopaedics and traumatology
J. Marciniak
Journal of Achievements in Materials and Manufacturing Engineering , 2010,
Abstract: Purpose: the paper is to characterize stainless steel of modyfied sufrace as a material used in orthopaedics andtraumatology on the example of LCP (Locking Compression Plate) used in long bones treatment.Design/methodology/approach: In order to reach the goal biomechanical analyses, both numerical andexperimental, were carried out. The results of the analyses are the basis for selecting geometrical features ofa plate stabiliser and biomaterial mechanical properties. The degree of stress and deformation also determinesareas where corrosion can start to develop. Chromium-nickel-molybdenum steel widely applied for makingimplants used in orthopaedics and traumatology was selected for testing implant surface modification. Passiveand passive-carbon films were formed on the implants. The structure of the created films was tested togetherwith their susceptibility to deformation and resistance to corrosion.Findings: It was shown that formation of passive-carbon DLC coatings is an effective method of increasingsteel resistance to pitting, crevice and stress corrosion and of increasing its biocompatibility.Practical implications: The proposed surface treatment seems to be effective method that allow to reduce therisk of post-surgical complications. The coatings can be formed by using electrolytic polishing and passivationand a final RF PACVD process.Originality/value: The author also presents results of the coating surface topography examination, results oftests on its chemical and phase structure as well as mechanical and physicochemical properties.
Experimental and numerical analysis of urological stents
W. Kajzer,J. Marciniak
Archives of Materials Science and Engineering , 2007,
Abstract: Purpose: In order to evaluate the characteristic changes of the stents’ diameters in function of the elongation (during elastic expansion) the biomechanical tests were carried out. The numerical analysis of the selected forms of urological stents was performed. The numerical results were compared with the experimental ones.Design/methodology/approach: The urethral stent commonly used in clinical practice was analyzed. Two types of research were carried out: experimental – in order to determine the displacement characteristic of the stent, and numerical (by means of the finite element method) – in order to evaluate stresses and strains in the stent. Findings: The comperative analysis of the obtained experimantal and numerical results showed good correlation, that proves the proper selection of the modeling conditions, and boundary conditions adequate to the real object.Research limitations/implications: The limitations were connected with the necessity of simplifications applied to the numerical model of the urological stent, and also with the difficulties caused by the established boundary conditions.Practical implications: The self-expanding stents analyzed in the work are implants for which the change of the diameter causes the significant change of the length. Due to the fact, the very important issue during implantation of this type of stent is the appropriate positioning in the narrowed part of urethra. The worked out characteristics allows to determine the length of the implant for the given diameter.Originality/value: The work presents the dispacement characteristics of the stent obtained on the basis of the experimental and numerical tests. The correlation of the obtained results is also presented.
Numerical method in biomechanical analysis of intramedullary osteosynthesis in children
A. Krauze,J. Marciniak
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The paper presents the biomechanical analysis of intramedullary osteosynthesis in 5-7 year old children.Design/methodology/approach: The numerical analysis was performed for two different materials (stainless steel – 316L and titanium alloy – Ti-6Al-4V) and for two different fractures of the femur (1/2 of the bone shaft, and 25 mm above). Furthermore, the stresses between the bone fragments were calculated while loading the femur with forces derived from the trunk mass. In the research the Metaizeau method was applied. This method ensures appropriate fixation without complications.Findings: The numerical analysis shows that stresses in both the steel and the titanium alloy nails didn’t exceed the yield point: for the stainless steel Rp0,2,min = 690 MPa and for the titanium alloy Rp0,2,min = 895 MPa.Research limitations/implications: The obtained results are the basis for the optimization of mechanical properties of the metallic biomaterial.Practical implications: On the basis of the obtained results it can be stated that both stainless steel and titanium alloy nails can be aplied in elastic osteosythesis in femur fractures in children.Originality/value: The obtain results can be used by physicians to ensure elastic osteosythesis that accelerate bone union.
The preoperative miniplates treatment - influence on the corrosion behavior
A. Zi?bowicz,J. Marciniak
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The fundamental aim of this paper was to determine the corrosion behavior of miniplates with thepassive-carbon layer in in vitro and in vivo tests into account the implantation technique.Design/methodology/approach: Corrosion resistance has been tested in the solution simulating tissueenvironments at temperature 37±1°C by recording of anodic polarization curves with the use of thepotentiodynamic method. The VoltaLab PGP 201 system for electrochemical tests has been applied. Chemicalcomposition investigations of the adjacent tissue to the retrieved implants have been carried out with the use ofscanning electron microscopy and energy-dispersive X-ray microanalysis (SEM-EDS)Findings: The paper presents preoperative surface treatment and its influence on corrosion and topographicalproperties and it can be useful for implants producers to take into consideration. That kind of surface coatingsensure high corrosion resistance of the implants in spite of damage while load bearing and during operation(prebending of implants). Coatings are flexible enough and wear resistant too.Research limitations/implications: The future research should be focused on the evaluation of new miniplatedesign and optimization of the surgical procedure.Practical implications: On the basis of the obtained results it can be stated that miniplates made of stainlesssteel with the passive-carbon layer can be applied in maxillo-facial surgery.Originality/value: The investigations indicate that the deformation of the surface layer does not depend on theresistance of implant to corrosion.
Expandable intramedullary nail - experimental biomechanical evaluation
A. Kajzer,W. Kajzer,J. Marciniak
Archives of Materials Science and Engineering , 2010,
Abstract: Purpose: The paper presents results of experimental analysis of femur and femur – expandable intramedullary nail system. The aim of the work was to determine displacement in three models. In addition, the torsion of the system aiming at determining the moments depending on the torsional angle of the bone was carried out.Design/methodology/approach: Three femurs were selected for studies. The analysis was carried out on the femur – expandable intramedullary nail system. The influence of the loads and displacements on the bone – nail system on the results of experimental analysis was analysed. In order to carry out calculations, three models were selected: model I – bone without fracture gap, model II and III – femur with expansion intramedullary nails – fracture gap was located 100 mm under greater trochanter. The studies were performed on femur models produced by Swedish company Sawbones. The intramedullary Fixion IM” nails (Ti-6Al-4V alloy) were implanted into the bone. Displacements of determinated models were being recorded from the sensors every 100 N from 10 N to 2000 N.Findings: The analyses showed the difference in displacements, depending on the selected models.Research limitations/implications: The limitations were connected with simplification of boundary conditions during analysis which were the result of the simplification of the models. While studying, muscles and ligaments supporting the bone in anatomic position were not taken into consideration. Instead, the system has been loaded with the axial force (compression).Practical implications: The obtained results can be useful in clinical practice. They can be applied in selection of stabilization methods or rehabilitation as well as in describing the biomechanical conditions connected with type of bone fracture obtained from medical imaging.Originality/value: . The work compares the values of displacement of characteristic points of femur (healthy – model I) with the femur – expandable intramedullary nail system (models II and III) with the applied force. In order to estimate the value of the torsional angle of the upper part in relation to the lower one depending on the applied force, the torsion of the model was conducted. On this basis, it was indicated a maximum moment in which the nail would not become loose in medullar canal.
Biomechanical analysis of plates used in treatment of pectus excavatum
A. Krauze,J. Marciniak,A. Marchacz
Archives of Materials Science and Engineering , 2007,
Abstract: Purpose: The paper presents computer simulation results of displacement, strain and stresses in the plate used in treatment of the pectus excavatum.Design/methodology/approach: The numerical analysis was performed for selected models of the stabilizing plates made of the Cr-Ni-Mo stainless steel (AISI 316L) and Ti-6Al-4V ELI alloy.Findings: The displacement, strain and stress analyses showed the diverse results depending on the plates geometry and the properties of the applied metallic biomaterial. The numerical analysis shows that stresses in plates didn’t exceed the yield point: for the stainless steel Rp0,2min=690 MPa and Ti-6Al-4V ELI - Rp0,2min=895 MPa.Research limitations/implications: The limitations were connected both with the necessity of simplifications applied to the numerical model and with the established boundary conditions.Practical implications: The obtained results are the basis for the stabilizing plate optimization to ensure favorable conditions for the pectus excavatum treatment.Originality/value: The work presents the displacement-strain-stress characteristics obtained on the basis of the numerical analysis.
Corrosion resistance of metallic implants used in bone surgery
M. Kiel,A. Krauze,J. Marciniak
Archives of Materials Science and Engineering , 2008,
Abstract: Purpose: The purpose of the research was analysis of influence of mechanical damages on the implants’ surfacemade of Cr-Ni-Mo steel on the pitting corrosion resistance. Analysis was performed for implants after differenttime of implantation applied for stabilization of the funnel chest and for stabilization bone fractures, as well as forintramedullary nails in the initial state.Design/methodology/approach: Research were performed on three groups of implants after differentimplantation time. Research were based on the potentiodinamic tests by recording the anodic polarization curves.The tests were performed in the Tyrode’s physiological solution.Findings: The research effect was determination the corrosion potential Ecorr and breakdown potential Eb for threegroups of implants after different time of implantation and different mechanical surface damages. On the basis ofinvestigation it was stated that for all implants the breakdown potential was in the range of Eb = +549 – +1017 mVand the corrosion potential was in the range of Ecorr = -143 – +103 mV.Research limitations/implications: The obtained results can be applied to comparing the effects of possiblepostoperative complications. They also show the relation between the damage of surface layers and implantationtime. The values of corrosion and breakdown potentials indicate good corrosion resistance of the applied austeniticstainless steel.Practical implications: The essential influence on the corrosion resistance had the time of implantation andsize of surface damages. The results of research of implants made of Cr-Ni-Mo austenitic stainless steel presentsthat the steel was performed quality requirements for metallic biomaterials used for tested implants.Originality/value: The work presents the results of pitting corrosion tests for metallic implants made of Cr-Ni-Mo steel in the initial state and after different implantation time.
Influence of medium and surface modification on corrosion behaviour of the cobalt alloy
W. Kajzer,M. Kaczmarek,J. Marciniak
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The work presents the influence of artificial urine environment and surface treatment of Co-Cr-W-Ni alloy, intended for implants applied in urogenital surgery, on their corrosion resistance. The tests were carried out in three artificial urine solutions that differed in chemical composition at the temperature 37±1°C and pH = 5.6-6.4. In particular, the pitting and crevice corrosion resistance tests were carried out.Design/methodology/approach: The corrosion tests were realized by recording of anodic polarization curves with the use of the potentiodynamic method. The VoltaLab PGP 201 system for electrochemical tests was applied. The tests were carried out in electrolyte simulating urine (pH = 5.6-6.4) at the temperature of 37±1°C.Findings: The obtained results indicate diverse corrosion resistance of the Co-Cr-W-Ni alloy depending on the applied surface treatment and chemical composition of the artificial urine that can be connected with individual reactivity of patients.Research limitations/implications: The obtained results are the basis for optimization of physicochemical properties of the Co-Cr-W-Ni alloy and allow to select only one artificial urine solution for further corrosion tests.Practical implications: On the basis of the obtained results it can be stated that Co-Cr-W-Ni alloy can be applied in urology.Originality/value: The paper presents the influence of artificial urine environment and the surface treatment on corrosion resistance of Co-Cr-W-Ni alloy.
Numerical analysis of femur in living and dead phase
A. Krauze,M. Kaczmarek,J. Marciniak
Journal of Achievements in Materials and Manufacturing Engineering , 2008,
Abstract: Purpose: The paper presents numerical analysis results of stresses and displacement in femur in a living and a dead phase. The aim of the work was to present the influence of different mechanical properties of bone tissue on the obtained results. The appropriate selection of the properties ensures correct results, comparable with the results obtained in real conditions.Design/methodology/approach: The analysis was carried out on the femur of adult. The influence of the selected properties on the results of numerical analyses was analyzed. In order to carry out calculations, 3 models of diverse mechanical properties (Young modulus of bone in a living phase EI=17260 MPa, Young modulus in order to carry out a comparison analysis EII.=18600 MPa and Young modulus of bone in a dead phase EIII=20202 MPa) were selected.Findings: The analyses showed the difference in displacements and reduced stresses depending on the selected mechanical properties. The analyses show that in order to select the appropriate stabilization method, mechanical characteristics of bone structures should be considered as viscoelastic. Quality of bone structures depends on individual features (genetic, hormonal, metabolic and circulatory factors).Research limitations/implications: The limitations were connected with simplification of numerical model of femur as well as with the selected boundary conditions.Practical implications: The obtained results can be useful in clinical practice. They can be applied in selection of stabilization methods or rehabilitation as well as in describing the biomechanical conditions connected with type of bone fracture obtained from medical imaging.Originality/value: Stress – displacement characteristics of femur for different degrees of demineralization, obtained from the numerical analyses were presented in the work.
FEM analysis of compression screws used for small bone treatment
W. Kajzer,A. Kajzer,J. Marciniak
Journal of Achievements in Materials and Manufacturing Engineering , 2009,
Abstract: Purpose: The paper presents results of numerical analysis in metatarsal bone I” - compression screws system. The aim of the work was determined stresses, strain and displacement in the inserted screws.Design/methodology/approach: Metatarsal bone I” was selected to researches. The analysis was carried out on the metatarsal bone I” - compression screws system. The influence of the loads and displacements on the bone - screws system on the results of numerical analyses was analyzed. In order to carry out calculations, 2 models of diverse mechanical properties of screw - Ti-6Al-4V alloy - model 1, stainless steel (Cr-Ni-Mo) - model 2 and two load steps were selected.Findings: The analyses showed the difference in displacements, strains and stresses depending on the selected mechanical properties screws and the way of loads.Research limitations/implications: The limitations were connected with simplification of numerical model of femur as well as with the selected boundary conditions. Two difference way of loads metatarsal bone I” - compression screws system: 1_force F = 500 N, 2_ displacement l = 1 mm were applied.Practical implications: The obtained results can be useful in clinical practice. They can be applied in selection of stabilization methods or rehabilitation as well as in describing the biomechanical conditions connected with type of bone fracture obtained from medical imaging.Originality/value: Stress-strain-displacement characteristics of metatarsal bone I” - compression screws system, obtained from the numerical analysis were presented in the work.
Page 1 /297552
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.