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1
Comparative Wear Model on Hybrid Natural Fiber Composites as Substitutions for UHMWPE Made Knee Implants
Kitap Bölümü

Kitap Bölümü
Kaynak :
Wiley Online Library
Dergi:
Synthesis and Tribological Applications of Hybrid Materials
Yayıncı:
Wiley-VCH Verlag GmbH & Co. KGaA
Yazar(lar) :
Gusztáv Fekete , Mátyás Andó
Yıl :
2018
Gusztáv Fekete
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This chapter gives a brief introduction about polymers to understand hybrid natural fiber composites (NFCs). Next, it discusses the possible use of hybrid NFCs and in total knee replacements (TKR). Among the numerous possible applications, companies involved in biomedical part production are interested in this new type of materials as a possible substitution for ultra‐high molecular weight polyethylene (UHMWPE) manufactured elements. The chapter then introduces an enhanced wear model that can be a useful tool for estimating wear outcome for NFCs, if the specific wear coefficient is available. For this, a classical UHMWPE material is chosen to give an insight on how the analytical wear model works if knee‐specific parameters such as the slide‐roll ratio or the varying load in case of non‐standard and standard squat are incorporated into it. The chapter then introduces a more realistic mathematical approach on wear propagation between the tibiofemoral connections.
DOI : 10.1002/9783527808588.ch8
ISBN:9783527343010
Sayfa: 139-161
2
Biomechanical Analysis of Augments in Revision Total Knee Arthroplasty.
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
PubMed
Dergi:
J Biomech Eng
Yazar(lar) :
Bernardo Innocenti , Gusztáv Fekete , Silvia Pianigiani
Yıl :
2018
Gusztáv Fekete
Yayıncı Web Sitesi
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Kaydet Alıntıla
Augments are a common solution for treating bone loss in revision total knee arthroplasty and industry is providing to surgeons several options, in terms of material, thickness and shapes. Actually, while the choice of the shape and the thickness is mainly dictated by the bone defect, no proper guidelines are currently available to select the optimal material for a specific clinical situation. Nevertheless, different materials could induce different bone responses and, later, potentially compromise implant stability and performances. Therefore, in this study, a biomechanical analysis is performed by means of finite element modelling about existing features for augment designs. Based upon a review of available products at present, the following augments features were analyzed: position (distal/proximal and posterior), thickness (5, 10 and 15 mm) and material (bone cement, porous and solid metal). For all analyzed configurations, bone stresses were investigated in different regions and compared among all configurations and the control model for which no augments were used. Results show that the use of any kind of augment usually induces a change in bone stresses, especially in the region close to the bone cut. The porous metal presents result very close to cement ones; thus it could be considered as a good alternative for defects of any size. Solid metal has the least satisfying results inducing the highest changes in bone stress. The results of this study demonstrate that material stiffness of the augment should be as close as possible to bone properties for allowing the best implant performances.
DOI : 10.1115/1.4040966
Sınıflandırma :
3
Ba Duan Jin Preliminary Analysis of the Second Type of Plantar Pressure
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Physical Activity and Health
Yazar(lar) :
Jia Ye , Dong Sun , Gusztáv Fekete
Yıl :
2018
Gusztáv Fekete
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Kaydet Alıntıla
The mainly subject of this study was a common Ba Duan Jin (BDJ) practitioner. The plantar pressure distribution of nine distinct regions was analyzed during the execution of the one typical BDJ movements and Normal Walking (NK). The result of the experiment demonstrated that in BDJ movements, the pressure-time integral (PTI) of the 1st MTH was the maximum and greater than other parts in BDJ movements. The peak pressure (PP) of the 1st 2nd 3rd MTH and the GT were markedly greater than in other regions (p < 0.05). The center of pressure (COP) focused on the 1st 2nd 3rd MTH, and movement displacement is little. The result indicated that the 1st MTH plantar pressure of the second type of BDJ movement relative to NK a larger, to strengthen the 1st MTH and the GT region skin sensation, improving balance control. The plantar pressure distribution characteristics of BDJ movements found in this study may be one of the important factors that BDJ exercise improves elderly balance control.
DOI : 10.5334/paah.4
Anahtar Kelimeler : Ba Duan Jin, Plantar pressure, Balance
ISSN: 2515-2270
Cilt: 2
Sayı: 1
Sayfa: 1 - 7
4
The effect of walking speed on the foot inter-segment kinematics, ground reaction forces and lower limb joint moments
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak 1:
Directory of Open Access Journals (DOAJ)
Kaynak 2:
PubMed
Yazar(lar) :
Dong Sun , Gusztáv Fekete , Qichang Mei , Yaodong Gu
Yıl :
2018
Gusztáv Fekete
Tam Metin
Kaydet Alıntıla
Background Normative foot kinematic and kinetic data with different walking speeds will benefit rehabilitation programs and improving gait performance. The purpose of this study was to analyze foot kinematics and kinetics differences between slow walking (SW), normal walking (NW) and fast walking (FW) of healthy subjects. Methods A total of 10 healthy male subjects participated in this study; they were asked to carry out walks at a self-selected speed. After measuring and averaging the results of NW, the subjects were asked to perform a 25% slower and 25% faster walk, respectively. Temporal-spatial parameters, kinematics of the tibia (TB), hindfoot (HF), forefoot (FF) and hallux (HX), and ground reaction forces (GRFs) were recorded while the subjects walked at averaged speeds of 1.01 m/s (SW), 1.34 m/s (NW), and 1.68 m/s (FW). Results Hindfoot relative to tibia (HF/TB) and forefoot relative to hindfoot (FF/HF) dorsiflexion (DF) increased in FW, while hallux relative to forefoot (HX/FF) DF decreased. Increased peak eversion (EV) and peak external rotation (ER) in HF/TB were observed in FW with decreased peak supination (SP) in FF/HF. GRFs were increased significantly with walking speed. The peak values of the knee and ankle moments in the sagittal and frontal planes significantly increased during FW compared with SW and NW. Discussion Limited HF/TB and FF/HF motion of SW was likely compensated for increased HX/FF DF. Although small angle variation in HF/TB EV and FF/HF SP during FW may have profound effects for foot kinetics. Higher HF/TB ER contributed to the FF push-off the ground while the center of mass (COM) progresses forward in FW, therefore accompanied by higher FF/HF abduction in FW. Increased peak vertical GRF in FW may affected by decreased stance duration time, the biomechanical mechanism maybe the change in vertical COM height and increase leg stiffness. Walking speed changes accompanied with modulated sagittal plane ankle moments to alter the braking GRF during loading response. The findings of foot kinematics, GRFs, and lower limb joint moments among healthy males may set a reference to distinguish abnormal and pathological gait patterns.
DOI : 10.7717/peerj.5517
Anahtar Kelimeler : Kinetics, Foot kinematics, Walking speed, Multi-segment foot model
ISSN: 2167-8359
Cilt: 6
Sayfa: e5517
Sınıflandırma :
5
Cytotoxic and radiosensitizing potential of silver nanoparticles against HepG-2 cells prepared by biosynthetic route using Picrasma quassioides leaf extract
Dergi Makalesi

Dergi Makalesi
Kaynak :
Science Direct
Dergi:
Journal of Drug Delivery Science and Technology
Yayıncı:
Elsevier
Yazar(lar) :
Kumari Jyoti , Ajeet Singh , Gusztáv Fekete , Tej Singh
Yıl :
2020
Gusztáv Fekete
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Kaydet Alıntıla
Synthesizing silver nanoparticles (AgNPs) from medicinal plants is an emerging and eco-friendly biosynthetic route. An aqueous extract of Picrasma quassioides (P. quassioides) leaves was used for the synthesis of AgNPs. The synthesized AgNPs were characterized using different methods, namely; ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), dynamic light scattering (DLS) and atomic force microscope (AFM). The UV–Vis spectrum of the synthesized AgNPs showed absorption peak at 412 nm. The FTIR study provides evidence for the occurrence of possible biomolecules responsible for the reduction of silver ions to a zero-valent metal as well as capping agent that helps in increasing the stability of the fabricated AgNPs. The XRD pattern analysis revealed peaks at 38.35° (111), 46.75° (200), 64.65° (220) and 77.75° (311) corresponding to the diffraction facets of silver. TEM, AFM and SEM analysis showed that the AgNPs were almost spherical in shape with an average size of 5–40 nm. Cytotoxic and radiosensitization potential of AgNPs formulation was determined on HepG-2 cell lines.
DOI : 10.1016/j.jddst.2019.101479
Anahtar Kelimeler : Picrasma quassioides, AgNPs, TEM, AFM, Anticancerous, Radiosensitization
ISSN: 1773-2247
Cilt: 55
Sayfa: 101479
Sınıflandırma :
6
Optimal design of needlepunched nonwoven fiber reinforced epoxy composites using improved preference selection index approach
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Journal of Materials Research and Technology
Yazar(lar) :
Tej Singh , Sachin Tejyan , Amar Patnaik , Ranchan Chauhan , Gusztáv Fekete
Yıl :
2020
Gusztáv Fekete
Yayıncı Web Sitesi
Kaydet Alıntıla
Viscose and polypropylene fiber-based needlepunched nonwoven fabric mat reinforced epoxy composites with varying mass per unit area (200, 400 and 600 g/m2) and varying fabric mat weight percentage (20, 30, and 40 wt.%) were fabricated. The manufactured composites were characterized for physical (density, void content), mechanical (impact energy, flexural, tensile and inter-laminar shear strength) and erosive wear properties. The evaluated properties were considered as performance defining attributes (PDAs) for the assessment of the composites. The experimental results indicate that there was no single composite which satisfied all the selected PDAs. Therefore, the improved preference selection index (PSI) approach was proposed to select the best composite alternative which yielded optimized physico-mechanical and erosive wear properties by considering all the PDAs at a single time. It was found that the composite alternative containing 40 wt.% of 600 g/m2 polypropylene fiber displayed the optimal physico-mechanical and erosive wear properties.
Anahtar Kelimeler : Needlepunched nonwoven fiber, Polymer composite, Physico-mechanical, Erosive wear, Improved PSI
Cilt: 9
Sayı: 4
Sayfa: 7583 - 7591
Sınıflandırma :
7
Physical, mechanical, and thermal properties of Dalbergia sissoo wood waste‐filled poly(lactic acid) composites
Dergi Makalesi

Dergi Makalesi
Kaynak :
Wiley Online Library
Dergi:
Polymer Composites
Yazar(lar) :
Tej Singh , László Lendvai , Gábor Dogossy , Gusztáv Fekete
Yıl :
2021
Gusztáv Fekete
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The present work intended to investigate the effect of Dalbergia sissoo wood waste on physical, mechanical, and thermal properties of poly(lactic acid) (PLA)‐based composites. The composite specimens, containing wood waste (2.5%, 5%, 7.5%, and 10% by weight) mixed with PLA granules, were prepared by melt compounding. It was found that increased wood waste content resulted in higher modulus, porosity, and water absorption with decreased density, tensile strength, impact strength, and stress at break. Nevertheless, the flexural strength values of the composites were similar to unfilled PLA and they remained almost constant irrespective of the wood waste content. Differential scanning calorimetry analysis revealed that the presence of wood waste content increased the glass transition and cold crystallization temperature of the PLA composites. Moreover, the fractured surfaces of the composites were examined with a scanning electron microscope to study the possible failure mechanisms. The conducted investigations demonstrated that low‐cost wood waste‐based composites can be used as an environmentally and economically attractive substitute for lightweight applications.
DOI : 10.1002/pc.26155
ISSN: 0272-8397
Sayı: 9
Cilt: 42
Sayfa: 4380-4389
8
The Effect of Prolonged Running on the Symmetry of Biomechanical Variables of the Lower Limb Joints
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak 1:
Directory of Open Access Journals (DOAJ)
Kaynak 2:
MDPI
Dergi:
Symmetry
Yazar(lar) :
Zixiang Gao , Qichang Mei , Gusztáv Fekete , Julien S Baker , Yaodong Gu
Yıl :
2020
Gusztáv Fekete
Piri Tam Metin Bulucu
Kaydet Alıntıla
The aim of this study was to examine whether there are kinematic and kinetic differences in the lower limb and whether the symmetry of the lower extremities is different after prolonged-running. Fifteen healthy male amateur runners (age: 22 ± 1 years, height: 173 ± 8 cm, mass: 65 ± 7 kg, BMI: 21.62 ± 2 kg/m2) were recruited as participants for this study. A Vicon eight-camera motion capture system and Kistler force plate were used to collect kinematic and kinetic parameters. A motorized treadmill, 15-point Borg scale and heart rate bands were used to monitor fatigue during a running-induced fatigue protocol. Paired sample T tests were used to check statistical difference (p = 0.05) between the lower limbs and the symmetry changes in pre-fatigue and post-fatigue running sessions. The symmetry angle (SA) of the knee flexion angle, hip flexion angle and hip extension angle in post-fatigue was significantly greater than in pre-fatigue, increasing by 4.32%, 10.71%, and 23.12%, respectively. Moreover, the SA of hip flexion moment increased by 2.61%. However, the knee extension velocity and hip flexion velocity became more symmetrical than in pre-fatigue (p < 0.05), the SA decreased by 5.91% and 5.45%, respectively. Differences in limb function during post-fatigue may lead to changes of symmetry in the lower limbs. The variables of asymmetry may be used as a compensation mechanism to maintain gait stability. Physical therapy assessment of fatigue injuries and long-distance running training programs may want to consider the changes in symmetry due to limb dominance.
DOI : 10.3390/sym12050720
Anahtar Kelimeler : Symmetry, fatigue, prolonged running
ISSN: 2073-8994
Cilt: 12
Sayı: 720
Sayfa: 720
9
Parametric Optimization of Erosive Wear Response of TiAlN-Coated Aluminium Alloy Using Taguchi Method
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Journal of Materials Engineering and Performance
Yazar(lar) :
Vinayaka R. Kiragi , Amar Patnaik , Tej Singh , Gusztáv Fekete
Konu :
Mechanical Engineering, Mechanics of Materials, General Materials Science
Yıl :
2019
Gusztáv Fekete
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In this research work, high-velocity oxy-fuel thermal spraying is used to develop TiAlN coatings on AA1050 and AA5083 aluminium alloy substrates. Slurry wear behavior of coatings is evaluated using jet-type test rig. Surface studies were carried out to investigate the potential erosion mechanism. The influence of key parameters identified using the Taguchi analysis is also corroborated with a wear model. The potential mechanism identified by wear model is in excellent convergence with that observed experimentally. Mixed ploughing and cutting, formation of platelets, abrasion grooves and cracks are witnessed as primary mechanisms causing loss of coating. Results indicate that impact velocity is recognized as a highly contributing parameter with contribution ratio of 79.24 and 83.75% followed by impingement angle with contribution ratio of 15.81 and 11.58% for AA1050 and AA5083, respectively. The important sequences of the control parameters are recognized to be impact velocity > impingement angle > erodent feed rate > erodent size for AA1050 and impact velocity > impingement angle > erodent size > erodent feed rate for AA5083. The best possible combination of control parameters for AA1050 and AA5083 to achieve minimal wear rate with respect to impact velocity, erodent size, impingement angle and erodent feed rate is 30 m/s, 225 µm, 30°, 160 g/min and 25 m/s, 150 µm, 30°, 160 g/min, respectively.
DOI : 10.1007/s11665-018-3816-6
Anahtar Kelimeler : Aluminium alloy, erosive wear, HVOF coating, Taguchi method
ISSN: 1059-9495 1544-1024
Sayı: 2
Cilt: 28
Sayfa: 838-851
10
Application of hybrid analytical hierarchy process and complex proportional assessment approach for optimal design of brake friction materials
Dergi Makalesi

Dergi Makalesi
Kaynak :
Wiley Online Library
Dergi:
Polymer Composites
Yazar(lar) :
Tej Singh , Amar Patnaik , Gusztáv Fekete , Ranchan Chauhan , Brijesh Gangil
Yıl :
2018
Gusztáv Fekete
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In this article, hybrid analytical hierarchy process (AHP) and complex proportional assessment (COPRAS) approach was proposed to optimize automotive brake friction materials. Sixteen formulations based on phenolic resin, barium sulfate, Kevlar fiber, Lapinus fiber, multiwall carbon nanotube (MWCNT), nanoclay and graphite were formulated and evaluated for tribological properties. The tribo‐evaluation parameters such as coefficient of friction, friction‐fluctuations, friction‐variability, friction‐fade, wear, friction‐recovery, friction‐stability and disc temperature rise were considered as criterion for the performance optimization. The optimization of formulations was carry out in two steps: (1) finding the weight of each criterion by AHP method and (2) ranking the formulations with COPRAS method. The AHP‐COPRAS results show that the formulation of 50 wt% barium sulfate, 15 wt% phenolic resin, 2.5 wt% graphite, 5 wt% Kevlar fiber, 25 wt% Lapinus fiber with 2.5 wt% MWCNT exhibits the optimal tribological properties. POLYM. COMPOS., 40:1602–1608, 2019. © 2018 Society of Plastics Engineers
DOI : 10.1002/pc.24907
ISSN: 0272-8397
Sayı: 4
Cilt: 40
Sayfa: 1602-1608
11
Analyzing the effect of an arch support functional insole on walking and jogging in young, healthy females.
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
PubMed
Dergi:
Technol Health Care
Yazar(lar) :
Xiaoxue Zhao , Meizi Wang , Gusztáv Fekete , Julien S Baker , Huw Wiltshire , Yaodong Gu
Yıl :
2018
Gusztáv Fekete
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Kaydet Alıntıla
The aim of this study was to explore the effectiveness of arch support functional insoles to prevent metatarsalgia.
DOI : 10.3233/THC-181373
Anahtar Kelimeler : Arch support, biomechanics, gait, insoles
Sınıflandırma :
12
Comparative performance assessment of pineapple and Kevlar fibers based friction composites
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Journal of Materials Research and Technology
Yazar(lar) :
Tej Singh , Catalin I. Pruncu , Brijesh Gangil , Vedant Singh , Gusztáv Fekete
Yıl :
2020
Gusztáv Fekete
Yayıncı Web Sitesi
Kaydet Alıntıla
Novel friction composites materials using pineapple fiber as a sustainable alternative for automotive industry were developed by increasing its amount from 5−20 wt.% in the step of 5 %. To compare the performance of pineapple fiber, friction composites with 5−10 wt.% of Kevlar fiber were also manufactured. The results of physico-mechanical properties reveal that density, hardness and ash content decrease whereas water absorption, porosity and compressibility increase with the increased pineapple/Kevlar fiber contents. Further, the friction and fade performance were found to decrease whereas the recovery performance and wear was found to increase with increased pineapple fiber content. Among pineapple fiber reinforced composites, the best composite is the one having 5 wt.% pineapple fibers that exhibits the highest performance in terms of coefficient of friction (0.548), lowest fade-% (36.31 %) along with the lowest specific wear rate (3.49 × 10−8 cm3/N-m). Nonetheless, the results show that the 5 wt.% Kevlar fiber based composite reveals good performance in terms of coefficient of friction (0.592) with slightly lower fade-% (35.98 %), recovery-% (107.43 %) and specific wear rate (3.46 × 10−8 cm3/N-m) when comparing to 5 wt.% pineapple fiber based composites. Finally, the possible wear mechanisms were discussed with the help of composites worn surface morphologies. Keywords: Pineapple fiber, Kevlar fiber, Polymer composite, Brake materials
Cilt: 9
Sayı: 2
Sayfa: 1491 - 1499
Sınıflandırma :
13
Selection of natural fibers based brake friction composites using hybrid ELECTRE-entropy optimization technique
Dergi Makalesi

Dergi Makalesi
Kaynak :
Science Direct
Dergi:
Polymer Testing
Yayıncı:
Elsevier
Yazar(lar) :
Tej Singh , Punyasloka Pattnaik , Catalin I. Pruncu , Avinash Tiwari , Gusztáv Fekete
Yıl :
2020
Gusztáv Fekete
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Selecting the best brake friction composite composition amongst a set of natural fibres reinforced composites using hybrid optimization method - ELECTRE (elimination and choice translating priority) II - entropy is discussed in this article. Three sets of natural fibres containing different amounts of banana, hemp, and pineapple reinforced brake friction composites were tested according to IS 2742 (part-4) regulations on a chase friction testing machine. The experimental results have been discussed in terms of seven performance defining attributes such as coefficient of friction, fade, wear, friction stability coefficient, friction recovery, friction fluctuations, and friction variability coefficient. The composite containing 5 wt% pineapple fiber exhibit the highest coefficient of friction, whereas wear performance and friction stability remain highest for 5 wt% hemp fiber based composites. The recovery performance remains highest for the composite containing 15 wt% banana fiber, while fade, friction variability, and fluctuations remain lowest for 10 wt% banana fiber reinforced composites. The tribological results indicate that the inclusion of disparate natural fibers in varying amounts may differently affect the tribological performances and therefore to choose the best brake friction composite satisfying the maximum beneficial criteria hybrid ELECTRE II- entropy optimization technique is used. Brake friction composite containing ~10 wt% banana fibers was ranked first, in meeting the desired performance tribological properties. A comparison of this optimization approach with other multi-criteria decision-making techniques is also made for validating the performance ranking of these composites.
DOI : 10.1016/j.polymertesting.2020.106614
Anahtar Kelimeler : Natural fibers, Polymer composite, Brake material, ELECTRE II, Optimization
ISSN: 0142-9418
Cilt: 89
Sayfa: 106614
Sınıflandırma :
14
A systematic review on gait analysis methods and assistive devices in lower limb prosthetics
Dergi Makalesi

Dergi Makalesi
Kaynak :
Science Direct
Dergi:
Materials Today: Proceedings
Yayıncı:
Elsevier BV
Yazar(lar) :
Radheshyam Rathor , Amit Kumar Singh , Himanshu Choudhary , Chandramani Goswami , Gusztáv Fekete
Yıl :
2021
Gusztáv Fekete
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Kaydet Alıntıla
In recent years there is a high demand for assistive devices for the lower limb amputees. Assistive devices play a major role in rehabilitation post prosthesis globally due to problems associated with the prosthesis. This literature research aims to find out an affordable, accessible, and easy to adapt assistive devices for lower limb amputees to analyze gait cycle post prosthesis. The performance of different techniques used to analyze the walking patterns of patients having lower limb amputations by the previous researchers is presented. The efforts made by healthcare professionals in developing rehabilitation duration and prognostics are also identified. A structured review of the literature of the rehabilitation, assistive devices used is carried out. The various methods for the synthesis of planar single and multi-loop linkages along with the methods for defect-rectification are explored. This review addresses the gait analysis methods and assistive devices in lower limb prosthetics systematically and thoroughly.
DOI : 10.1016/j.matpr.2020.10.541
Anahtar Kelimeler : Lower limb amputation, Prosthesis, Gait analysis, Gait assistive devices
ISSN: 2214-7853
Cilt: 44
Sayfa: 4251-4255
15
Do Novice Runners Show Greater Changes in Biomechanical Parameters?
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Hindawi Limited
Dergi:
Applied Bionics and Biomechanics
Yayıncı:
Hindawi
Yazar(lar) :
Wenjing Quan , Feng Ren , Dong Sun , Gusztáv Fekete , Yuhuan He
Yıl :
2021
Gusztáv Fekete
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Kaydet Alıntıla
Purpose. Examining and understanding the biomechanics of novice runners and experienced runners can further improve our knowledge within the field of running mechanics and running injuries. The purpose of this study was to classify the differences in lower limb biomechanics during a 3.3 m/s running task among both experienced runners and novice runners. Method. Twenty-four participants (12 experienced runners and 12 novice runners) ran at 3.3 m/s across a force plate; kinematics and kinetics data were collected by the Vicon motion system and Kistler force plate. Group comparisons were made using an independent samples -test to identify differences in the impact peak, loading rate, contact time, ankle, knee, and hip joint kinematics and kinetics during the stance phase. Results. No significant differences were observed between novice and experienced runners for both ankle and knee joint kinetics except that the ankle joint plantar flexion torque was significantly greater in the novice runners. However, the plantar flexion, dorsiflexion, range of motion (ROM), plantar flexion torque, and max angular velocity of ankle joint significantly increased in novice runners than inexperienced runners. Additionally, the flexion angle and range of motion of the hip joint were observed to be larger in the novice runners. Moreover, the maximum extension torque and the maximum extension power in the hip joint were significantly increased in the experienced runners. There were no significant differences in the first peak, contact time, and average vertical loading rate. Novice runners showed a larger vertical instantaneous loading rate than experienced runners. Conclusion. These preliminary findings indicate that novice runners are prone to running injuries in comparison to experienced runners. Novice runners showed larger kinematics and kinetic parameters in the joint of the ankle and hip. Novice runners should enhance muscle strength in the hip and choose scientific training methods.
DOI : https://doi.org/10.1155/2021/8894636
Cilt: 2021
ISSN: 1176-2322
Sınıflandırma :
16
Comparative 3-dimensional kinematic analysis of snatch technique between top-elite and sub-elite male weightlifters in 69-kg category.
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak 1:
PubMed
Kaynak 2:
Directory of Open Access Journals (DOAJ)
Dergi:
Heliyon
Yazar(lar) :
Gongju Liu , Gusztáv Fekete , Hongchun Yang , Jing Ma , Dong Sun , Qichang Mei , Yaodong Gu
Yıl :
2018
Gusztáv Fekete
Piri Tam Metin Bulucu
Kaydet Alıntıla
The purpose of this study was to determine the differences in technical characteristics between top-elite and sub-elite male weightlifters performing the snatch style in the 69-kg category. The obtained results can provide valuable information for lower level lifters and coaches to achieve better competition performance by altering their training methods accordingly.
DOI : 10.1016/j.heliyon.2018.e00658
Anahtar Kelimeler : Physiology
Sınıflandırma :
17
Tibiofemoral wear in standard and non-standard squat: implication for total knee arthroplasty.
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
PubMed
Dergi:
Muscles Ligaments Tendons J
Yazar(lar) :
Gusztáv Fekete , Dong Sun , Yaodong Gu , Patric Daniel Neis , Ney Francisco Ferreira , Bernardo Innocenti , Béla M Csizmadia
Yıl :
2018
Gusztáv Fekete
Yayıncı Web Sitesi
 Piri Tam Metin Bulucu
Kaydet Alıntıla
Due to the more resilient biomaterials, problems related to wear in total knee replacements (TKRs) have decreased but not disappeared. In the design-related factors, wear is still the second most important mechanical factor that limits the lifetime of TKRs and it is also highly influenced by the local kinematics of the knee. During wear experiments, constant load and slide-roll ratio is frequently applied in tribo-tests beside other important parameters. Nevertheless, numerous studies demonstrated that constant slide-roll ratio is not accurate approach if TKR wear is modelled, while instead of a constant load, a flexion-angle dependent tibiofemoral force should be involved into the wear model to obtain realistic results.
DOI : 10.11138/mltj/2017.7.4.520
Anahtar Kelimeler : analytical model, rehabilitation, slide-roll ratio, squat, tibiofemoral force, wear
Sınıflandırma :
18
Fabrication of Ceramic Hip Implant Composites: Influence of Silicon Nitride on Physical, Mechanical and Wear Properties
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Silicon
Yazar(lar) :
Chandramani Goswami , I. K. Bhat , Amar Patnaik , Tej Singh , Gusztáv Fekete
Konu :
Electronic, Optical and Magnetic Materials
Yıl :
2019
Gusztáv Fekete
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This study examined the effects of silicon nitride reinforcement on physical, mechanical and wear properties of different ceramic (zirconium oxide, magnesium oxide, chromium oxide and aluminum oxide) containing hip implant composites. The hip implant composites were produced using conventional mixing and spark plasma sintering methods by substituting aluminum oxide (68, 70.5, 73 and 75.5 wt.%) with silicon nitride (0, 2.5, 5 and 7.5 wt.%). Experimental results showed that silicon nitride content had significant effect on the evaluated physical, mechanical and wear properties. The density of the composites found to decrease whereas void content, Young’s modulus, hardness, wear resistance and fracture toughness first decreased (for 2.5 wt.%) and then increased with the increasing amount of silicon nitride content. The maximum hardness, Young’s modulus, wear resistance and fracture toughness values of 28.64 GPa, 280.18 GPa, 0.0076 mm3/million cycles and 11.84 MPa.m1/2, respectively were registered for 2.5 wt.% silicon nitride additions that also had the lowest void content (0.38%).
DOI : 10.1007/s12633-019-00222-5
Anahtar Kelimeler : Ceramic composite, Hip implants, Mechanical, Wear
ISSN: 1876-990X 1876-9918
Sayı: 5
Cilt: 12
Sayfa: 1237-1245
19
Health View to Decrease Negative Effect of High Heels Wearing: A Systemic Review
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Hindawi Limited
Dergi:
Applied Bionics and Biomechanics
Yayıncı:
Hindawi
Yazar(lar) :
Meizi Wang , Ci Jiang , Gusztáv Fekete , Ee-Chon Teo , Yaodong Gu
Yıl :
2021
Gusztáv Fekete
Yayıncı Web Sitesi
Tam Metin
Kaydet Alıntıla
Effective recommendations about how to decrease adverse effects of high heels (HH) need to be provided, since wearing HH is inevitable for most women in their daily life, regardless of their negative impacts on the foot morphology. The main purpose of this systematic review was to summarize studies which have provided specific information about how to effectively offset the negative effects of wearing HH, in the case of women, by means of examining heel height, insole, and heel base support (HBS). Some evidence indicate the following: (i) the range of appropriate heel height for HH shoes is 3.76 cm to 4.47 cm; (ii) compared to small HBS, the larger ones effectively increase gait stability, reduce risk of ankle injury, and improve comfort rating during HH walking; and (iii) the use of a total contact insert (TCI) significantly decreases plantar pressure and the impact on the foot, resulting in higher perceived comfort. It must be noted that these results are based on short-term research; therefore, any conclusions with regard to effects in the long term should be taken with a grain of salt. Nevertheless, future studies should be aimed at combining numerical and experimental methods, in order to provide personal recommendations for HH shoes by considering heel height and HBS size, based on the individual characters (weight, height, and age).
DOI : https://doi.org/10.1155/2021/6618581
Cilt: 2021
ISSN: 1176-2322
Sınıflandırma :
20
Utilization of Waste Marble Dust in Poly(Lactic Acid)-Based Biocomposites: Mechanical, Thermal and Wear Properties
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Journal of Polymers and the Environment
Yazar(lar) :
László Lendvai , Tej Singh , Gusztáv Fekete , Amar Patnaik , Gábor Dogossy
Konu :
Materials Chemistry, Polymers and Plastics, Environmental Engineering
Yıl :
2021
Gusztáv Fekete
Yayıncı Web Sitesi
Tam Metin
Kaydet Alıntıla
The aim of this present work was to study the applicability of waste marble dust (MD) in poly(lactic acid) (PLA)-based composites. Samples containing up to 20 wt% waste MD were prepared via melt blending. The attention was focused on the investigation of mechanical, morphological, thermal properties and the wear resistance of the PLA/MD composites. Regarding the mechanical properties, both the tensile and the flexural modulus improved remarkably, however, a slight loss was observed in strength and deformability. The impact toughness showed an increasing tendency up to 10 wt% MD loading, which was followed by a marginal decrease at higher concentration. With respect to the sliding wear rate, the composite with the highest MD content showed the best wear resistance. According to the DSC measurements, the MD hampered the chain mobility of PLA, thereby reducing the crystalline ratio. Overall, composites with improved properties were developed, while the reuse of waste MD is expected to reduce the production costs as well.
DOI : 10.1007/s10924-021-02091-9
Anahtar Kelimeler : Waste marble dust, Poly(lactic acid) (PLA), Melt mixing, Recycling, Biopolymer composites
ISSN: 1566-2543 1572-8919
Sayı: 9
Cilt: 29
Sayfa: 2952-2963
21
Natural-synthetic fiber reinforced homogeneous and functionally graded vinylester composites: Effect of bagasse-Kevlar hybridization on wear behavior
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Journal of Materials Research and Technology
Yazar(lar) :
Tej Singh , Brijesh Gangil , Bharat Singh , Shashi Kant Verma , Don Biswas , Gusztáv Fekete
Yıl :
2019
Gusztáv Fekete
Yayıncı Web Sitesi
Kaydet Alıntıla
In this work, vinylester resin based and hybrid Kevlar-bagasse fiber reinforced homogeneous and graded composites were developed and evaluated for wear performance on a pin-on-disc machine. An orthogonal array (L16) was applied to examine the influence of four tribological control factors i.e. fiber content, normal load, sliding distance and sliding velocity. The experimental results indicate that normal load emerges as the most important factor affecting the wear rate of vinylester based graded and homogeneous composites with a contribution ratio of 36.33% and 32.09% respectively. Furthermore, composites worn surfaces were analyzed using scanning electron microscopy and the possible wear mechanism was studied. Keywords: Bagasse fiber, Kevlar fiber, Graded composites, Sliding wear, Microscopy
Cilt: 8
Sayı: 6
Sayfa: 5961 - 5971
Sınıflandırma :
22
Foot Motion Character During Forward and Backward Walking With Shoes and Barefoot
Dergi Makalesi

Dergi Makalesi
Kaynak :
Taylor and Francis
Dergi:
Journal of Motor Behavior
Yayıncı:
Informa UK Limited
Yazar(lar) :
Dong Sun , Gusztáv Fekete , Julien S. Baker , Yaodong Gu
Konu :
Biophysics, Experimental and Cognitive Psychology, Cognitive Neuroscience, Orthopedics and Sports Medicine
Yıl :
2019
Gusztáv Fekete
Yayıncı Web Sitesi
Tam Metin
Kaydet Alıntıla
Backward walking (BW) has been extensively used in athletic training and orthopedic rehabilitation as it may have value for enhancing balance. This study identified the differences in foot intersegment kinematics (forward walking (FW) vs. time-reversed BW) and plantar pressure parameters of 16 healthy habitually shod individuals walking FW and BW using flexible shoes (SH) and under barefoot conditions (BF). BW was found to have shorter stride length (SL) and higher stride frequency (SF) under BF conditions compared with SH, which indicates a better BW gait stability under BF conditions. Decreased HX/FF dorsiflexion at HO in BW induces less plantar aponeurosis tension which may inhibit the windlass mechanism compared to FW walking. Increased forefoot relative to hindfoot (FF/HF) pronation and sequentially hindfoot relative to tibia (HF/TB) eversion combined with medially distributed plantar pressure and a higher plantar contact area in the medial side in BW–BF maybe beneficial in maintaining balance. These results indicate that BW training may be more reliable under BF conditions compared to the SH conditions based on greater sensory information feedback from the plantar area resulting in better biomechanical behavior.
DOI : 10.1080/00222895.2019.1605972
Anahtar Kelimeler : Foot kinematics, backward walking, shoes, barefoot
ISSN: 0022-2895
Sayı: 2
Cilt: 52
Sayfa: 214-225
23
Experimental investigation and multi objective optimization of thermal-hydraulic performance in a solar heat collector
Dergi Makalesi

Dergi Makalesi
Kaynak :
Science Direct
Dergi:
International Journal of Thermal Sciences
Yayıncı:
Elsevier
Yazar(lar) :
Ranchan Chauhan , Tej Singh , Amar Patnaik , N.S. Thakur , Sung Chul Kim , Gusztáv Fekete
Yıl :
2020
Gusztáv Fekete
Yayıncı Web Sitesi
Tam Metin
Kaydet Alıntıla
The air impinging normally through the jets over the heat transmitting surface prevents the development of boundary layer in its vicinity to a large extent. The variation in system control factors such as diameter of jet, streamwising and spanwising pitch have significant effect on the performance defining attributes of a rectangular channel forced convection fluid flow. An experimental investigation is performed to study the results outcome by alteration of the control factors on performance defining attributes based upon which multi attribute decision making approach (MADM) has been proposed for optimal combination of control factors. The performance defining attributes present a desperate trend in view of which it becomes imperative to optimize the control factors for maximum utility attribute (s) and minimum regret value of the undesired attribute (s) with simultaneous consideration of all. The hybrid analytical hierarchy process (AHP) and preference ranking organization method for enrichment evaluations (PROMETHEE) technique have been processed to meet the desired target. It has been observed that the jet diameter ratio: 0.065, streamwising pitch ratio: 0.435, spanwising pitch ratio: 0.869 and Reynolds number: 16000 is the best combination of control factors among all others to deliver the highest overall performance with same energy input in each case.
DOI : 10.1016/j.ijthermalsci.2019.106130
Anahtar Kelimeler : Solar heat collector, Performance index, MADM, AHP, PROMETHEE
ISSN: 1290-0729
Cilt: 147
Sayfa: 106130
Sınıflandırma :
24
A Pilot Study of Musculoskeletal Abnormalities in Patients in Recovery from a Unilateral Rupture-Repaired Achilles Tendon
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
International Journal of Environmental Research and Public Health
Yazar(lar) :
Dong Sun , Gusztáv Fekete , Julien S. Baker , Qichang Mei , Bíró István , Yan Zhang , Yaodong Gu
Yıl :
2020
Gusztáv Fekete
Yayıncı Web Sitesi
 Piri Tam Metin Bulucu
Kaydet Alıntıla
The purpose of this study was to compare the inter-limb joint kinematics, joint moments, muscle forces, and joint reaction forces in patients after an Achilles tendon rupture (ATR) via subject-specific musculoskeletal modeling. Six patients recovering from a surgically repaired unilateral ATR were included in this study. The bilateral Achilles tendon (AT) lengths were evaluated using ultrasound imaging. The three-dimensional marker trajectories, ground reaction forces, and surface electromyography (sEMG) were collected on both sides during self-selected speed during walking, jogging and running. Subject-specific musculoskeletal models were developed to compute joint kinematics, joint moments, muscle forces and joint reaction forces. AT lengths were significantly longer in the involved side. The side-to-side triceps surae muscle strength deficits were combined with decreased plantarflexion angles and moments in the injured leg during walking, jogging and running. However, the increased knee extensor femur muscle forces were associated with greater knee extension degrees and moments in the involved limb during all tasks. Greater knee joint moments and joint reaction forces versus decreased ankle joint moments and joint reaction forces in the involved side indicate elevated knee joint loads compared with reduced ankle joint loads that are present during normal activities after an ATR. In the frontal plane, increased subtalar eversion angles and eversion moments in the involved side were demonstrated only during jogging and running, which were regarded as an indicator for greater medial knee joint loading. It seems after an ATR, the elongated AT accompanied by decreased plantarflexion degrees and calf muscle strength deficits indicates ankle joint function impairment in the injured leg. In addition, increased knee extensor muscle strength and knee joint loads may be a possible compensatory mechanism for decreased ankle function. These data suggest patients after an ATR may suffer from increased knee overuse injury risk.
DOI : 10.3390/ijerph17134642
Anahtar Kelimeler : Achilles tendon rupture, musculoskeletal modeling, ankle
Cilt: 17
Sayı: 4642
Sayfa: 4642
Sınıflandırma :
25
A Preventive Role of Exercise Across the Coronavirus 2 (SARS-CoV-2) Pandemic
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Dergi:
Frontiers in Physiology
Yazar(lar) :
Meizi Wang , Meizi Wang , Julien S. Baker , Wenjing Quan , Siqin Shen , Gusztáv Fekete , Yaodong Gu
Yıl :
2020
Gusztáv Fekete
Yayıncı Web Sitesi
 Piri Tam Metin Bulucu
Kaydet Alıntıla
The coronavirus 2019 (COVID-19) pandemic has posed a significant threat to human health around the world. A severe risk of infection has been observed in elderly populations. In addition, individuals with obesity and obesity-related comorbidities have also been identified to be at a higher risk of infection for COVID-19. We have attempted here to provide evidence in support of exercise management as a prevention strategy for improving health and minimizing the effects of COVID-19. Therefore, exercise duration, frequency, and intensity benefits are summarized in an attempt to provide guidelines for the general population. In terms of exercise effects, there are multiple benefits of exercise related to human health. These include, decreases in adipose tissue, improvements in cardio-respiratory fitness, enhanced metabolic homeostasis, and suppress inflammation active. With respect to the amount of exercise performed individuals should exercise at a moderate intensity for at least 150 min/wk as an initial target. Increases in intensity and duration of exercise training are necessary for significant fitness benefits, weight loss, and prevention of weight regain. In relation to walking, 10,000 steps/day at a rate of 64–170 steps/minute for at least 10 min duration is reasonable for healthy adults. For exercise intensity, a combination of resistance training (RT), aerobic training (AT) as well as high-intensity interval training (HIIT) incorporated with moderate-intensity continuous training (MICT) can be recognized as an optimal exercise mode for health benefits. Aerobic training and MICT should be viewed as a basis for exercise in combination with appropriate volumes and types of RT and HIIT. Activities should be performed according to professional guidelines and advice. If implemented, these measures may reduce infection rates, underlying pathologies, and assist in decreasing mortality associated with COVID-19 pandemic.
DOI : 10.3389/fphys.2020.572718
Anahtar Kelimeler : coronavirus 2019, obesity, overweight, exercise, health
ISSN: 1664-042X
Cilt: 11
Sınıflandırma :
26
Fabrication of waste bagasse fiber‐reinforced epoxy composites: Study of physical, mechanical, and erosion properties
Dergi Makalesi

Dergi Makalesi
Kaynak :
Wiley Online Library
Dergi:
Polymer Composites
Yazar(lar) :
Tej Singh , Sachin Tejyan , Amar Patnaik , Vedant Singh , Ibolya Zsoldos , Gusztáv Fekete
Konu :
Materials Chemistry, General Chemistry, Polymers and Plastics, Ceramics and Composites
Yıl :
2019
Gusztáv Fekete
Yayıncı Web Sitesi
Tam Metin
Kaydet Alıntıla
The aim of the research work is to study the physical, mechanical, and erosive wear properties of sugarcane bagasse fiber‐reinforced epoxy composites. The physical (density, void content) and the mechanical (hardness, tensile strength, impact energy, flexural strength) properties of the composites were found to increase with the content of bagasse fiber. For erosive wear analysis, the experiments were carried out with the help of erosion test machine. To minimize the erosive wear rate, Taguchi technique is executed to explore the influence of five control factors including fiber content, impact velocity, impingement, stand‐off distance, and erodent size at three levels. Using Taguchi (L27) orthogonal array, the optimal combination of control factors, which yielded minimum erosive wear rate, was statistically predicted and experimentally verified. The fiber content and impact velocity were the two most contributing control factors for the minimization of erosive wear rate. The important sequence of the parameters is fiber content > impact velocity > impingement angle > erodent size > stand‐off distance. The optimal combination of control factors was obtained at 10 wt% of fiber content, 30 m/s of impact velocity, 30° of impingement angle, 85 mm of stand‐off distance, and 250 μm of erodent size. Finally, composites worn surfaces were examined with scanning electron microscope to study the possible erosive wear mechanism. POLYM. COMPOS., 40:3777–3786, 2019. © 2019 Society of Plastics Engineers
DOI : 10.1002/pc.25239
ISSN: 0272-8397
Sayı: 9
Cilt: 40
Sayfa: 3777-3786
27
PATELLOFEMORAL MODEL OF THE KNEE JOINT UNDER NON- STANDARD SQUATTING
Dergi Makalesi

Dergi Makalesi
Open Access
Kaynak :
Directory of Open Access Journals (DOAJ)
Yazar(lar) :
GUSZTÁV FEKETE , BÉLA MÁLNÁSI CSIZMADIA , MAGD ABDEL WAHAB , PATRICK DE BAETS , LIBARDO V. VANEGAS-USECHE , ISTVÁN BÍRÓ
Yıl :
2014
GUSZTÁV FEKETE
Yayıncı Web Sitesi
Kaydet Alıntıla
Los modelos analíticos disponibles para calcular las fuerzas patelofemorales de la rodilla están limitados al movimiento estándar de cuclillas cuando el centro de gravedad es fijo horizontalmente. En este artículo se presenta un modelo para calcular con exactitud las fuerzas patelofemorales, teniendo en cuenta el cambio de posición del centro de gravedad del tronco durante una sentadilla profunda (posición de sentadilla modificada). Se valida la exactitud del modelo desarrollado mediante comparaciones con resultados de la técnica de dinámica inversa.
Cilt: 81
Sayı: 183
Sayfa: 60 - 67

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