scholarly journals Biosynthesis of Polyhydroxybutyrate with Cellulose Nanocrystals Using Cupriavidus necator

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2604
Author(s):  
Giyoung Shin ◽  
Da-Woon Jeong ◽  
Hyeri Kim ◽  
Seul-A Park ◽  
Semin Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Fourier Transform ◽  
Cellulose Nanocrystals ◽  
Liquid Culture ◽  
Culture Media ◽  
Cupriavidus Necator ◽  
Decomposition Products ◽  
Specific Strength ◽  
High Specific Strength

Polyhydroxybutyrate (PHB) is a natural polyester synthesized by several microorganisms. Moreover, it has excellent biodegradability and is an eco-friendly material because it converts water and carbon dioxide as final decomposition products. However, the applications of PHB are limited because of its stiffness and brittleness. Because cellulose nanocrystals (CNCs) have excellent intrinsic mechanical properties such as high specific strength and modulus, they may compensate for the insufficient physical properties of PHB by producing their nanocomposites. In this study, natural polyesters were extracted from Cupriavidus necator fermentation with CNCs, which were well-dispersed in nitrogen-limited liquid culture media. Fourier-transform infrared spectroscopy results revealed that the additional O–H peak originating from cellulose at 3500–3200 cm−1 was observed for PHB along with the C=O and –COO bands at 1720 cm−1. This suggests that PHB–CNC nanocomposites could be readily obtained using C. necator fermented in well-dispersed CNC-supplemented culture media.

Effect of Core Thickness and Intermediate Layers on Mechanical Properties of Polypropylene Honeycomb Multi-Layer Sandwich Structures

2014 ◽  
Vol 59 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. Arbaoui ◽  
Y. Schmitt ◽  
J.-L. Pierrot ◽  
F.-X. Royer
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structures ◽  
Bending Test ◽  
Honeycomb Core ◽  
Lightweight Construction ◽  
Specific Strength ◽  
High Specific Strength ◽  
Intermediate Layers ◽  
Core Thickness ◽  
Strength And Stiffness

Abstract Sandwich structures are widely used in lightweight construction especially in aerospace industries because of their high specific strength and stiffness. This paper investigates the effect of core thickness and intermediate layers on the mechanical properties of a polypropylene honeycomb core/composite facing multilayer sandwich structure under three points bending. We developed a theoretical model which makes it possible to calculate the shear properties in multi-cores. The results obtained by this model are agreed with our experimental results, and the results obtained with bending test showed that the mechanical properties of the composite multilayer structures increase with core thickness and intermediate layers.

Analysis and Simulation of the Shear Deformation for Woven Cloth

2011 ◽  
Vol 201-203 ◽  
pp. 203-208
Author(s):  
Liang Chen ◽  
Shu Guang Zhao ◽  
Li Juan Zhang ◽  
Li Qiang Zhang ◽  
Wen Bing Zhang
Keyword(s):  
Mechanical Properties ◽  
Shear Deformation ◽  
Mechanical Model ◽  
Shear Behavior ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Cloth Simulation ◽  
Specific Strength ◽  
High Specific Strength

Woven fabrics are used in a wide variety of products, and they are prized for their flexibility, formability, and high specific strength. However, modeling woven cloth is difficult due, in particular, to complex mechanical properties. In this paper, the shear behavior of plain woven fabric is studied. Through the analysis, a mechanical model is proposed which take the shearing properties into account. It uses physical-based model for animating cloth objects. Furthermore, we demonstrate the efficiency of this method with examples related to accurate cloth simulation from experimental shear curve measured on actual materials.

scholarly journals Microstructure and Mechanical Properties of Rapidly Solidified β-Type Ti–Fe–Sn–Mo Alloys with High Specific Strength and Low Elastic Modulus

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1135 ◽  
Author(s):  
Li ◽  
Ma ◽  
Jia ◽  
Meng ◽  
Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Volume Fraction ◽  
High Yield ◽  
Specific Strength ◽  
High Specific Strength ◽  
Microstructure And Mechanical Properties ◽  
Low Elastic Modulus ◽  
Mo Content ◽  
Rapidly Solidified

The microstructure and mechanical properties of rapidly solidified β-type Ti–Fe–Sn–Mo alloys with high specific strength and low elastic modulus were investigated. The results show that the phases of Ti–Fe–Sn–Mo alloys are composed of the β-Ti, α-Ti, and TiFe phases; the volume fraction of TiFe phase decreases with the increase of Mo content. The high Fe content results in the deposition of TiFe phase along the grain boundary of the Ti phase. The Ti75Fe19Sn5Mo1 alloy exhibits the high yield strength, maximum compressive strength, large plastic deformation, high specific strength, high Vickers hardness, and large toughness value, which is a superior new engineering material. The elastic modulus (42.1 GPa) of Ti75Fe15Sn5Mo5 alloy is very close to the elastic modulus of human bone (10–30 GPa), which indicating that the alloy can be used as a good biomedical alloy. In addition, the large H/Er and H3/Er2 values of Ti75Fe19Sn5Mo1 alloy indicate the good wear resistance and long service life as biomedical materials.

Mechanical Properties of Al2O3 Reinforced Cast and Hot Extruded Al Based Metal Matrix Composites

2015 ◽  
Vol 813-814 ◽  
pp. 208-212
Author(s):  
S. Ghanaraja ◽  
K.L. Vinuth Kumar ◽  
K.S. Ravikumar ◽  
B.M. Madhusudan
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Base Alloy ◽  
High Strength ◽  
Matrix Composites ◽  
Specific Strength ◽  
Good Corrosion Resistance ◽  
High Specific Strength ◽  
Low Weight

The Synthesis of aluminium matrix composites is receiving considerable emphasis in meeting the requirements of various industries. Due to the desired properties such as low weight, high specific strength, good corrosion resistance and excellent wear resistance, they have received a great interest in the recent years. Metal-matrix composites (MMCs) based on aluminium and magnesium has emerged as an important class of materials and Al2O3can be considered as ideal reinforcements, due to their high strength, high aspect ratio and thermo-mechanical properties. The objective of this work is to reinforce Al 1100-Mg alloy with different wt% of Al2O3(0, 3, 6, 9 and 12) was added by melt stirring method and Extrusion is carried out (extrusion ratio of 12.25) for the same alloy and composites. Mechanical property like hardness and tensile properties have been investigated for cast and extruded of base alloy and composites.

Evaluation of Mechanical Properties of Coconut Coir Fiber Reinforced Polymer Matrix Composites

2013 ◽  
Vol 24 ◽  
pp. 34-45 ◽  
Author(s):  
P.N.E. Naveen ◽  
T. Dharma Raju
Keyword(s):  
Mechanical Properties ◽  
Natural Fiber ◽  
Fiber Reinforced Polymer ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Specific Strength ◽  
Reinforced Plastics ◽  
Reinforced Polymer ◽  
High Specific Strength ◽  
Fiber Reinforced Plastics

Fiber-reinforced polymer composites have played a dominant role for a longtime in a variety of applications for their high specific strength and modulus. The fiber which serves as a reinforcement in reinforced plastics may be synthetic or natural. Past studies show that only synthetic fibers such as glass, carbon etc., have been used in fiber-reinforced plastics. Although glass and other synthetic fiber-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. An attempt has been made to utilize the coir, as natural fiber abundantly available in India. Natural fibers are not only strong and lightweight but also relatively very cheap. The present work describes the development and characterization of a new set of natural fiber based polyester composites consisting of coir as reinforcement and epoxy resin. Coir composites are developed and their mechanical properties are evaluated, at five different volume fractions and tests were carried out and the results were presented. Experimental results showed tensile, static and Dynamic properties of the composites are greatly influenced by increasing the percentage of reinforcement, and indicate coir can be used as potential reinforcing material for many structural and non-structural applications.

Fractography and Structural Analysis of WE43 and Elektron 21 Magnesium Alloys with Unmodified and Modified Grain Size

2012 ◽  
Vol 191 ◽  
pp. 123-130
Author(s):  
Stanisław Roskosz ◽  
Bartłomiej Dybowski ◽  
Jan Cwajna
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Smelting Process ◽  
Steering Wheel ◽  
Low Density ◽  
Specific Strength ◽  
High Specific Strength ◽  
Metallic Inclusions ◽  
Optimal Set ◽  
Very High

Magnesium alloys, thanks to their low density, are characterized by very high specific strength and specific stiffness. Due to acceptable mechanical properties, these alloys are widely used in automotive and aerospace industries for the elements such as: gearbox and engine housings, steering wheel columns or wheels. The main problem of the most common magnesium alloys – such as AZ91 are their weak high temperature properties. This led to development of alloys containing rare earth elements. These alloys achieve their demanded mechanical properties after grain refinement with the zirconium. Because of a big responsibility of the elements made from Mg-RE alloys, it is important to investigate modification impact on properties of the magnesium alloys. The paper presents results of studies properties of the WE43 and Elektron 21 casting magnesium alloys, modified in three different ways – according to Magnesium-Elektron specification, 50% stronger modification and 100% stronger. For the comparison, unmodified alloys were also investigated. Investigations showed, that alloys modified according to MEL specification presents optimal set of structural and mechanical properties. Further increase of amount of modifiers doesn’t let to significant increase of mechanical properties. Fractographic investigations showed many non-metallic inclusions on the fractures surface, which are result of faulty smelting process.

Effects of Diluent on Mechanical Properties of Hollow Glass Microsphere Reinforced Epoxy Resin Composite

2016 ◽  
Vol 680 ◽  
pp. 525-528
Author(s):  
Hai Tao Geng ◽  
Jia Chen Liu ◽  
Sue Ren
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Epoxy Resin ◽  
Resin Composite ◽  
Hollow Glass Microsphere ◽  
Hollow Glass Microspheres ◽  
Hollow Glass ◽  
Specific Strength ◽  
High Specific Strength ◽  
Epoxy Resin Composite

In order to improve the mechanical properties of hollow glass microspheres (HGMs) reinforced epoxy resin composite, diluent was added in the system of epoxy resin. The results revealed that more HGMs can be filled in the epoxy resin when appropriate amount diluent was added in the system, thus composite with relative low bulk density 0.70g/cm3 and high compressive strength 71.85MPa was obtained. It was due to that the diluent reduce the viscosity of the epoxy resin, which ensures uniform wetting of the fillers and enables more HGMs to be filled in resin. Besides, addition of diluent improved the adhesive strength between the epoxy resin and HGMs, making the composite having a relative high specific strength and can be used in weight sensitive filed.

New Recrystallisation Behaviour Seen in Magnesium Alloy Elektron 675

2012 ◽  
Vol 715-716 ◽  
pp. 171-172
Author(s):  
D. Randman ◽  
J. Corteen ◽  
W.M. Rainforth ◽  
B.P. Wynne ◽  
B. Davis
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Ternary System ◽  
Magnesium Alloys ◽  
Low Density ◽  
Fuel Savings ◽  
Specific Strength ◽  
High Specific Strength ◽  
Superior Mechanical Properties

There has recently been renewed interest in magnesium alloys from both the automotive and aerospace industries. Due to the low density (approximately 35% lower than aluminium) and high specific strength, these alloys can introduce significant weight savings, and consequently fuel savings, to both vehicles and aircraft. Elektron™ 675 is a new alloy based on the magnesium-yttrium-gadolinium ternary system, developed by Magnesium Elektron Ltd. for wrought applications. Elektron™ 675 has superior mechanical properties relative to the current commercially available wrought alloys AZ31B, WE43, and ZK60.

Evaluation of Structural Honeycomb Sensitivity to Filler Metal Reinforcement

2019 ◽  
Author(s):  
Joshua P. Flach ◽  
Paul S. Blanton
Keyword(s):  
Mechanical Properties ◽  
Complex Loading ◽  
Honeycomb Structure ◽  
Radioactive Material ◽  
Specific Strength ◽  
Structural Support ◽  
High Specific Strength ◽  
Regulatory Testing ◽  
Specific Geometry ◽  
Structure Density

Abstract Structural honeycomb is widely used as both an impact limiter and rigid structural support in applications which require a high specific strength and highly characterized energy absorption profile. Structural honeycomb is an anisotropic material with limited strength in directions perpendicular to the cells and features mechanical properties that are largely driven by the materials of construction and structure density. As a result, the mechanical properties of honeycomb are sensitive to the specific geometry, orientation, and reinforcement of the honeycomb structure. This study evaluates the effects of these characteristics on stainless steel structural honeycomb to account for the complex loading conditions experienced during radioactive material package regulatory testing. This material is intended for use in applications where organically bonded honeycomb cannot be used.

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