scholarly journals The potency of natural and synthetic composites for ballistic resistance: A review

2020 ◽  
Vol 1 (2) ◽  
pp. 43-55
Author(s):  
Mohd Yuhazril bin Yaakob ◽  
Mohamad Pazlin bin Saion ◽  
Mohd Amirhafizan bin Husin
Keyword(s):  
Synthetic Fibre ◽  
Fibre Composite ◽  
Mechanical Energy ◽  
Impact Resistance ◽  
Laminated Composite ◽  
Natural Fibre ◽  
The Body ◽  
Ballistic Resistance ◽  
Artificial Fibre ◽  
Natural And Synthetic

Mechanical characteristics of the laminated composite crafted from fabric type reinforcement perhaps inspired via the weaving method and reinforcement agent's usage due to each layer's constructional parameter. As a result, research on the arrangement configuration between bio composite and synthetic fibre for the material shape was proposed to enhance the composite structure's biodiversity and physical characteristics. Substitute for natural fibre in synthetic fibre composite works has shown the excessive capacity to be explored scientifically. The evaluation focused on the concept and essential of bio composite and the synthetic composite fabric positioned over the years from the previous studies of the preliminary researches. The sorts and features of matrix and fibre filler reinforcement materials in composites were also discussed. This assessment's main findings indicated that the composite centre relied on the weave styles and inter-ply and interplay lamination roles. Therefore, the state-of-the-art intraply for synthetic fibre and bio composite fibre in a composite shape was anticipated performing higher in mechanical energy, particularly within the application of ballistic resistance, besides decreased dependency on artificial fibre. It would ultimately suggest the excellent weave sample designs in the proper combination shape of natural and synthetic fibres embedded with polymers. The statistical results were compared with the experimental parameters available inside the literature review. The review explains approximately the studies and evolution within the enhancement of characteristic fibres reinforced polymer composites in ballistic resistance use. This paper goes over the body armour's profitable and present advancement materials, structure and development procedures, and related works on upgrading ballistic energy captivation and upgrading the mechanical tenacity for high impact resistance applications.

scholarly journals The Influence of Natural and Synthetic Fibre Reinforcement on Wood-Gypsum Composites

2017 ◽  
Vol 11 (1) ◽  
pp. 350-362 ◽  
Author(s):  
Rodríguez-Liñán Carmen ◽  
Morales-Conde María J. ◽  
Rubio-De-Hita P. ◽  
Pérez-Gálvez F. ◽  
Pedreño-Rojas Manuel A.
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Glass Fibre ◽  
Mechanical Behaviour ◽  
Synthetic Fibre ◽  
Natural Fibre ◽  
Fibre Reinforcement ◽  
Experimental Procedure ◽  
Wood Shavings ◽  
Natural And Synthetic

Objective: This paper studies the influence of natural and synthetic fibres on the mechanical behaviour of recycled wood-gypsum composites. These composites of wood waste, such as wood shavings and sawdust, were tested using different proportions of each type of recycled wood. The fibres used, straw as a natural fibre and glass fibre as a synthetic fibre, were analysed in two different proportions. Method: The experimental procedure was based on the analysis of the physical properties, density and mechanical properties, flexural strength and compression of the reinforced mixtures. Water absorption by capillarity and the thermal behaviour of the new wood-gypsum materials were also studied. Results and Conclusion: The results show that the use of both types of fibres in the mixtures produces lighter composites, and reinforcement by glass fibre represents a significant increase in their flexural strength.

Fabrication and Comparison of Mechanical Properties of Jute and Glass Fibre Reinforced Composites

2014 ◽  
Vol 592-594 ◽  
pp. 344-348
Author(s):  
Ram Rohit ◽  
Linford Pinto ◽  
K.Mallikharjuna Babu ◽  
Martin Jebraj ◽  
Harsha R. Gudi
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Fibre Composite ◽  
Damping Ratio ◽  
Weight Ratio ◽  
High Strength ◽  
Natural Fibre ◽  
Mechanical Tests ◽  
Reinforced Composites ◽  
Artificial Fibre

The properties of fiber reinforced composites (FRP) like high strength to weight ratio, high stiffness to weight ratio, flexibility in design, ease of fabrication with economical savings as compared to metal alloys, make it an excellent choice for various range of products from building materials, sporting equipment, appliances, automotive parts, boats, canoe hulls to bodies for recreational vehicles. In this study the properties of natural fibre composite are compared with composite made of artificial fibres. The natural fibre chosen is jute fibre and the artificial fibre chosen is glass fiber. Polyester resin was the matrix used because of compatibility, cost effectiveness and easy availability. The composites were fabricated by Hand Layup technique and the number of layers of composite laminate was varied as three, four and five. The specimens were subjected to mechanical tests and Young’s Modulus, Ultimate Strength were evaluated. Modal analysis was carried out to determine the damping characteristics through damping ratio. A comparison of the two composites in terms of mechanical properties is made and the results are tabulated.

scholarly journals Self-rechargeable cardiac pacemaker system with triboelectric nanogenerators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hanjun Ryu ◽  
Hyun-moon Park ◽  
Moo-Kang Kim ◽  
Bosung Kim ◽  
Hyoun Seok Myoung ◽  
...  
Keyword(s):  
Medical Devices ◽  
Mechanical Energy ◽  
Cardiac Pacemaker ◽  
Operation Time ◽  
Lithium Ion ◽  
The Body ◽  
Body Motion ◽  
Triboelectric Nanogenerator ◽  
Implantable Medical Devices ◽  
Energy Harvesters

AbstractSelf-powered implantable devices have the potential to extend device operation time inside the body and reduce the necessity for high-risk repeated surgery. Without the technological innovation of in vivo energy harvesters driven by biomechanical energy, energy harvesters are insufficient and inconvenient to power titanium-packaged implantable medical devices. Here, we report on a commercial coin battery-sized high-performance inertia-driven triboelectric nanogenerator (I-TENG) based on body motion and gravity. We demonstrate that the enclosed five-stacked I-TENG converts mechanical energy into electricity at 4.9 μW/cm3 (root-mean-square output). In a preclinical test, we show that the device successfully harvests energy using real-time output voltage data monitored via Bluetooth and demonstrate the ability to charge a lithium-ion battery. Furthermore, we successfully integrate a cardiac pacemaker with the I-TENG, and confirm the ventricle pacing and sensing operation mode of the self-rechargeable cardiac pacemaker system. This proof-of-concept device may lead to the development of new self-rechargeable implantable medical devices.

scholarly journals Elastic energy savings and active energy cost in a simple model of running

2021 ◽  
Vol 17 (11) ◽  
pp. e1009608
Author(s):  
Ryan T. Schroeder ◽  
Arthur D. Kuo
Keyword(s):  
Elastic Energy ◽  
Energy Cost ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Metabolic Cost ◽  
The Body ◽  
Metabolic Energy ◽  
Energetic Cost ◽  
Mass Model ◽  
Human Running

The energetic economy of running benefits from tendon and other tissues that store and return elastic energy, thus saving muscles from costly mechanical work. The classic “Spring-mass” computational model successfully explains the forces, displacements and mechanical power of running, as the outcome of dynamical interactions between the body center of mass and a purely elastic spring for the leg. However, the Spring-mass model does not include active muscles and cannot explain the metabolic energy cost of running, whether on level ground or on a slope. Here we add explicit actuation and dissipation to the Spring-mass model, and show how they explain substantial active (and thus costly) work during human running, and much of the associated energetic cost. Dissipation is modeled as modest energy losses (5% of total mechanical energy for running at 3 m s-1) from hysteresis and foot-ground collisions, that must be restored by active work each step. Even with substantial elastic energy return (59% of positive work, comparable to empirical observations), the active work could account for most of the metabolic cost of human running (about 68%, assuming human-like muscle efficiency). We also introduce a previously unappreciated energetic cost for rapid production of force, that helps explain the relatively smooth ground reaction forces of running, and why muscles might also actively perform negative work. With both work and rapid force costs, the model reproduces the energetics of human running at a range of speeds on level ground and on slopes. Although elastic return is key to energy savings, there are still losses that require restorative muscle work, which can cost substantial energy during running.

Effect of Water Absorption Behaviour on Tensile Properties of Hybrid Jute-Roselle Woven Fibre Reinforced Polyester Composites

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Agung Efriyo Hadi ◽  
Tezara Cionita ◽  
Deni Fajar Fitriyana ◽  
Januar Parlaungan Siregar ◽  
Ahmed Nurye Oumer ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Fibre Composite ◽  
Unsaturated Polyester ◽  
Water Immersion ◽  
Tensile Modulus ◽  
Natural Fibre ◽  
Jute Fibre ◽  
Thickness Swelling ◽  
Effect Of Water

Incorporating natural fibre as reinforcement in the polymer matrix has shown a negative effect since the natural fibre is hydrophilic. The natural fibre easily absorbs water which causes an effect on the mechanical properties of the composites. The objective of this paper is to investigate the water absorption behaviour of hybrid jute-roselle woven fibre reinforced unsaturated polyester composite and the effect of water absorption in terms of tensile strength and tensile modulus. The effect of hybrid composite on the thickness swelling will be tested. The fabrication method used in this study is the hand lay-up technique to fabricate 2-layer and 3-layer composites with layering sequences of woven jute (J)/roselle (Ro) fibre. The results of the study showed that pure roselle fibres for 2 and 3-layer composites have the highest water absorption behaviour 3.86% and 5.51%, respectively, in 28 days) as well as thickness swelling effect, whereas hybrid J-Ro and J-J-Ro composites showed the least water absorption (2.65% and 3.76%, respectively) in 28 days) in both the tests. The hybridisation between jute and roselle fibres reduced water absorption behaviour and improved the fibres dimensional stability. The entire composites showed a decreasing trend for both tensile strength and tensile modulus strength after five weeks of water immersion. Jute fibre composite hybridised with roselle fibre can be used to reduce the total reduction of both tensile strength and tensile modulus throughout the whole immersion period. Moreover, the tensile testing showed that jute fibre composite hybridised with roselle fibre have produced the strongest composite with the highest tensile and modulus strength compared to other types of composites. The hybridisation of diverse fibre reinforcements aids in minimising the composite water absorption and thickness swelling, hence reducing the effect of tensile characteristics.

Physical parameters of neutrality in the work of an osteopathic physician

2021 ◽  
pp. 105-120
Author(s):  
A. A. Gurichev
Keyword(s):  
Mechanical Energy ◽  
The Body ◽  
Spatial Position ◽  
Physical Parameters ◽  
Labor Organization ◽  
Physical Fatigue ◽  
Support Points

An osteopathic practitioner often meets the problem of physical fatigue, which is caused by a forced posture, excessive tension of the muscles of the trunk and arms, irrational biomechanical patterns of posture and movements, lack of support points, or switching points of mechanical energy of movement (fulcrum). These factors lead together to fatigue, which is felt as weariness and prevents the development of a pathophysiological state of overwork. Prevention of overwork by an osteopathic doctor can consist of a number of measures of labor organization and ergonomics, one of which is building a state of physical neutrality — a spatial position of the body that allows working with the patient as efficiently as possible and minimizing fatigue.

Sign in / Sign up

Export Citation Format

Share Document