Effect of Plasticizers on the Physicochemical properties of Bioplastic Extracted from Banana Peels

Plasticizers are the binding substances used to increase the elasticity of materials. In this research work, bioplastic is extracted from banana peels using various plasticizers such as, glycerol, urea, distilled water and glucose. The prepared bioplastics were characterized by using Fourier-transform infrared spectroscopy (FTIR) spectroscopic analysis which showed that the peak at 3355 cm-1 indicate the H-bonding formation between N-H urea and starch. The physicochemical properties such as water absorption test, soil decomposition and load test of synthesized bioplastics were analyzed at ambient temperature. The water uptake analysis showed that bioplastic absorbs water for up to 4 days without being decay. The load test showed that urea plasticized bioplastic has a high tensile strength of 2.3 KPa. The result revealed that the bioplastic with glucose as a plasticizer showed the effective result in water uptake and soil decomposition test whereas the urea plasticized bioplastic showed relatively good tensile strength.

Mechanical and microstructural characterization of Ti-SiC reinforced AA5083 surface composites fabricated via friction stir process

A mixture of Titanium and silicon-carbide powders was embedded in the AA5083 matrix by Friction Stir Processing (FSP). Experiments were performed as per Taguchi L8 orthogonal array, and the effect of reinforcement on hot strength (at 100oC), processed zone (PZ) geometry, and microstructure were investigated. The effect of PZ geometry on the surface properties was also analyzed. The effect of heating the tensile test specimens to 540ºC on the strength at 100oC was also separately investigated. It was observed that surface hardness was significantly enhanced by FSP, and the highest mean hardness of 90.4 HV was observed. Furthermore, it was observed that the surface properties also significantly depend on PZ geometry. From experimental results, it was found that the specimens with the lowest width to depth ratio bears the highest hardness and vice versa. A clear effect of parameters was evident on the geometry of processed zones with a deep bowl, and shallow cup-shaped zones were formed with smaller and larger shoulder diameters, respectively. The samples were processed at 355 rpm, 63 mm/min, 17 mm shoulder, and 355 rpm, 80 mm/min. The 20 mm shoulder showed high tensile strength 292 MPa and 294 Mpa, respectively. The strength of these samples did not reduce much even after heating to 540oC.

Effect of the Structure Morphology on the Mechanical Properties of Crumpled Graphene Fiber

Crumpled graphene fiber is a promising structure to be a graphene precursor to enhance the production and mechanical properties of various carbon fibers. The primary goal of the present work is to study the crumpled graphene of different morphologies using molecular dynamics simulations to find the effect of the structural peculiarities on the mechanical properties, such as the tensile strength, elastic modulus, and deformation characteristics. Mono- and poly-disperse structures are considered under uniaxial tension along two different axes. As it is found, both structures are isotropic and stress–strain curves for tension along different directions are very similar. Young’s modulus of crumpled graphene is close, about 50 and 80 GPa; however, the strength of the polydisperse structure is bigger at the elastic regime. While a monodisperse structure can in-elastically deform until high tensile strength of 90 GPa, structure analysis showed that polydisperse crumpled graphene fiber pores appeared two times faster than the monodisperse ones.

Tilapia skin: technological advance in the treatment of burns?

Introduction: Burn is one of the greatest aggressions the body can suffer. The approach varies according to the degree of the burn, since the use of chlorhexidine, silver sulfadiazine, debridement of necrotic tissue, biosynthetic dressings and artificial skins. However, these latter two have high costs, so several studies have emerged with the objective of seeking more viable options, such as the use of Nile Tilapia skin in burns, due to its healing properties. That said, the present article has as a guide question: Is this new method, in fact, a technological advance as important for the treatment of burned patients as it appears to be? Objective: To analyze the use of Nile Tilapia skin in patients with burn injuries, as well as to compare with other pre-established techniques. Methods: This is an integrative bibliographic review with a qualitative approach. Data were collected through PubMed databases and Virtual Health Library (VHL), from 2015 to 2020. Results: The articles indicate a good prognosis to the use of Nile Tilapia skin in relation to the other options in force for the treatment of burns, with a significant advantage in reducing the number of dressings required, for better adhesion to the wound. Moreover, it presents microscopic characteristics similar to human skin, such as high tensile strength and breakage extension, reducing reepithelialization time and pain intensity, as well as reducing treatment costs. Conclusion: In view of the findings of the literature reported in the present review, it is concluded that studies with nile tilapia skin proves to be a revolutionary modality with benefits in the treatment of patients with superficial and deep skin lesions. Therefore, the researchers concluded, answering the guide question, that the new method is, yes, an important advance in the field of burn treatment, because it's employability is confirmed, besides demonstrating an advantage over some of the main preexisting alternatives.

SIFAT TARIK DAN SIFAT LENTUR PADA BODY MOTOR KOMPOSIT LAMINA DENGAN PERLAKUAN ALKALI

Composite is a combination of two or more materials that have different mechanical propertiesand characteristics. One of the reinforcement materials or reinforcement that is widely used is naturalmaterials. One of Indonesia's natural materials and a very large source of bamboo is widely used inbuilding construction as an alternative to wood because it has high flexibility and strength. To balancethe strength of bamboo with high tensile strength while low flexural strength, a solution is needed tomaximize the strength of bamboo by combining it with a bamboo composite system. In this study, bamboothat has been processed into woven sheets manually with plain weave type is then given a certain amountof epoxy resin and then a Tensile Strength Test is carried out using ASTM D3039 / D3039M and aflexural test using ASTM D7264 / 7264M to obtain maximum composite and flexural strength. After thetest was carried out, it was continued by observing the microstructure of the specimen using SEM(Scanning Electron Microscope). The results showed the tensile test value with a value of 50 Mpacompared to the ABS tensile strength value of 53 Mpa, the Modulus of Elasticity with a value of 0.38 GPacompared to the ABS modulus of elasticity of 0.41 Gpa. The results of the flexural test obtained flexuralstrength with a value of 47.06 Mpa compared to the value of ABS flexural strength of 49.6 Mpa, flexuralmodulus with a value of 0.52 Gpa compared to the value of ABS flexural modulus of 0.55 Gpa.

Modulation of Multiple Precipitates for High Strength and Ductility in Al-Cu-Mn Alloy

The category and morphology of precipitates are essential factors in determining the mechanical behaviors of aluminum alloys. It is a great challenge to synthetically modulate multiple precipitates to simultaneously improve strength and ductility. In the present work, by optimizing the precipitations of the GP zone, θ’-approximant and θ’ phase for an Al-Cu-Mn alloy, a high tensile strength of 585 MPa with large elongation of 12.35% was achieved through pre-deformation and aging. The microstructure evolution pattern was revealed by detailed characterizations of scanning electron microscopy and transmission electron microscopy. It was found that such high tensile strength of the samples was due to a combination of strengthening by the high density of dispersive fine precipitates and dislocations, and the high elongation to failure was primarily attributed to the multimodal precipitates and elimination of precipitation-free zones along the grain boundaries. The strategy proposed here is a promising way of preparing ultra-strong Al-Cu-Mn alloys.

In-Plane Strengthening of Unreinforced Masonry Walls by Glass Fiber-Reinforced Polyurea

Strengthening techniques have been employed in Korea to unreinforced masonry walls (UMWs) for several years to protect them from damage caused by the intermittent occurrence of earthquakes. Polyurea, which has a high tensile strength and elongation rate, can be utilized as a strengthening material to enhance the in-plane strength and ductility of UMWs. Glass fiber-reinforced polyurea (GFRPU) is a composite elastomer manufactured by progressively adding milled glass fiber to polyurea. The purpose of this study is to investigate the enhancement of the in-plane strength and ductility of UMWs using GFRPU, depending on the shape of the GFRPU coating on the wall. Four masonry wall specimens are tested with test variables of the number of strengthening sides and coating shapes. It is illustrated that the GFRPU reinforcement of masonry wall leads to enhanced load-carrying capacity, ductility, and energy absorption. An empirical formula to represent the degree of strengthening effected by GFRPU is proposed in this study. Doi: 10.28991/cej-2021-03091782 Full Text: PDF

A Nanosheet-Assembled SnO2-Integrated Anode

There is an ever-increasing trend toward bendable and high-energy-density electrochemical storage devices with high strength to fulfil the rapid development of flexible electronics, but they remain a great challenge to be realised by the traditional slurry-casting fabrication processes. To overcome these issues, herein, a facile strategy was proposed to design integrating an electrode with flexible, high capacity, and high tensile strength nanosheets with interconnected copper micro-fibre as a collector, loaded with a novel hierarchical SnO2 nanoarchitecture, which were assembled into core–shell architecture, with a 1D micro-fibre core and 2D nanosheets shell. When applied as anode materials for LIBs, the resultant novel electrode delivers a large reversible specific capacity of 637.2 mAh g−1 at a high rate of 1C. Such superior capacity may benefit from rational design based on structural engineering to boost synergistic effects of the integrated electrode. The outer shell with the ultrathin 2D nanoarchitecture blocks can provide favourable Li+ lateral intercalation lengths and more beneficial transport routes for electrolyte ions, with sufficient void space among the nanosheets to buffer the volume expansion. Furthermore, the interconnected 1D micro-fibre core with outstanding metallic conductivity can offer an efficient electron transport pathway along axial orientation to shorten electron transport. More importantly, the metal’s remarkable flexibility and high tensile strength provide the hybrid integrated electrode with strong bending and stretchability relative to sintered carbon or graphene hosts. The presented strategy demonstrates that this rational nanoarchitecture design based on integrated engineering is an effective route to maintain the structural stability of electrodes in flexible LIBs.

Knots Tied With High–Tensile Strength Tape Biomechanically Outperform Knots Tied With Round Suture

Background: Tape-type suture material is well-accepted in arthroscopy surgery. Purpose: To compare the knot security of a high–tensile strength round suture and high–tensile strength tape with commonly used arthroscopic knots. Study Design: Controlled laboratory study. Methods: We compared the performance of No. 2 braided nonabsorbable high-strength suture with that of 1.3-mm braided nonabsorbable high-strength tape. Five commonly used arthroscopic knots were investigated: the Roeder knot; the Western knot; the Samsung Medical Center (SMC) knot; the Tennessee knot; and a static surgeon’s knot. Seven knots were tied for each combination of knots and suture types. Knots were tied on a 30-mm circumferential metal post, and the suture loops were transferred to a materials testing machine. After preloading to 5 N, all specimens were loaded to failure. The clinical failure load, defined as the maximal force to failure at 3 mm of crosshead displacement, yield load, and stiffness, were recorded. A 2-way analysis of variance was used to determine differences between the groups. Results: Both suture type and knot type significantly affected the clinical failure load, yield load, and stiffness ( P = .002). The high-strength tape resulted in a significantly greater clinical failure load than the high-strength suture in the case of the Roeder knot, Western knot, and SMC knot ( P = .027, .005, and .016, respectively). When the high-strength round suture was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the Tennessee knot ( P = .011, .003, and .035, respectively) and the static surgeon’s knot ( P < .001 for all). When the high-strength tape was used, the Roeder knot, Western knot, and SMC knot resulted in significantly smaller clinical failure loads compared with the static surgeon’s knot ( P = .001, .001, and .003, respectively). Conclusion: The results of this study indicated that arthroscopic knots tied using 1.3-mm high-strength tape biomechanically outperformed knots tied using a No. 2 high-strength suture. While the static surgeon’s knot exhibited the best biomechanical properties, the Tennessee knot resulted in generally better biomechanical properties among the arthroscopic sliding knots. Clinical Relevance: Elongation and loosening of tied knots possibly affects the clinical results of repaired constructs.