Optimization of ultrasound assisted extraction (UAE) of β-d-glucan polysaccharides from Ganoderma lucidum for prospective scale-up

Three levels of three ultrasonic independent variables were optimized to obtain the maximum yield of water-soluble polysaccharides (PS) extracted from Ganoderma lucidum using response surface methodology (RSM). Box–Behnken design (BBD) was employed to evaluate the effects of ultrasonic variables on the yield of PS. The parameters that were considered for the optimization are ultrasound power (500–700 W), ultrasonic irradiation time (45–65 min) and temperature (70–90 °C). The analysis of variance suggested that the response dependent variable of yield of PS could be expressed by a quadratic polynomial model. The optimal theoretical extraction conditions were found to be an ultrasonic power of 590 W, an irradiation time of 58 min and a temperature of 81 °C. Under these conditions the predicted optimal yield was 52.33 mg. Whereas by following the optimized conditions, the yield of PS by experiments was found to be 52.28 mg which is in a very good agreement with the theoretically predicted one. These outcomes indicate the adequacy of quadratic polynomial model to represent the ultrasonic extraction variables within the ranges of investigation for a volume of 0.25 L; and any prospective scale-up may require modifications in the geometry of the extracting vessel due to the non-linear effects of power ultrasound

A comparative analysis of experimental and numerical investigations of composite tubes under axial and lateral loading

Quasi-static tests are performed in order to determine the crash behavior of composite tubes. The specimens are made from woven fiber carbon/epoxy. The crash experiments show that the tubes crushed in a progressive manner from one end to the other of the tubes while delamination was - taking place between the layers. In the simulation works described in this paper the ANSYS explicit finite element code is used to investigate the compressive properties and crushing response of circular carbon tube subjected to static axial and lateral loading and the results are compared with the experimental work. To better understand the details of the crash process, thin multi layer shell elements are used to model the walls of the circular tube. Finally, the design optimization technique is implemented to find an optimum composite configuration that has the maximum failure load and absorbs the most energy. The crash performance of a carbon composite shell is compared with an optimum carbon tube from the experimental work. 2010, INSInet Publication.Scopu

Thin-walled composite tubes using fillers subjected to quasistatic axial compression

It has been demonstrated that composites are lightweight, fatigue resistant and easily melded, a seemingly attractive alternative to metals. However, there has been no widespread switch from metals to composites in the automotive sector. This is because there are a number of technical issues relating to the use of composite materials that still need to be resolved including accurate material characterization, manufacturing and joining process. The total of 36 specimens have been fabricated using the fibre-glass and resin (epoxy) with a two different geometries (circular and corrugated) each one will be filled with five types of filler (Rice Husk, Wood Chips, Aluminium Chips, Coconut Fibre, Palm Oil Fibre) all these type will be compared with empty Tubes for circular and corrugated in order to comprehend the crashworthiness parameters (initial failure load, average load, maximum crushing load, load ratio, energy absorption, specific energy absorption, volumetric energy absorption, crushing force efficiency and crush strain relation) which are considered very sufficient parameters in the design of automotive industry parts. All the tests have been done using the "INSTRON Universal machine" which is computerized in order to simply give a high precision to the collection of the results, along with the use of quasi-static load to test and observe the behaviour of the fabricated specimens

Implementation of XFEM in the study of gear crack propagation behaviour using the SIF on different moments

Copyright © 2017 Inderscience Enterprises Ltd. The application of gears, especially spur gear, is widely available in most engineering applications. Especially for high module steel spur gear, it is used extensively in heavy machineries such as cranes and metal crushers. Therefore, it is crucial to avoid catastrophic damage to gears by understanding the crack behaviour. Provided the crack does not propagate into the rim, only minor accidents are likely to happen or else catastrophe may be expected again. Therefore, the study of crack behaviour on stress intensity factor (SIF) with different magnitude of moment was conducted. This study implemented the application of extended finite element method (XFEM) in ABAQUS to overcome the limitations of a conventional method, the finite element method (FEM). The need of re-meshing was avoided in this simulation. The crack propagation pathways were visualised using the 'STATUSXFEM'

Material design consideration for gear component using functional graded materials

Gears have numerous practical applications. It is an essential element for power transmission. It is used to increase or decrease the speed or change the direction of a power resource. When gears are operating, it will develop high stress concentration on the contact tooth surface. In practice most gear teeth fail due to surface contact, which is the most common failure. Selecting the ideal material for a gear tooth is significant for the purpose of operating gear system. This review study will increase additional understanding of ceramic functional graded materials (FGMs) and their applications and how these materials can solve the gear tooth surface problem. This study gives evidence that FGM is able to enhance the microstructure, mechanical properties of the gear and gives better hardness between two tooth surfaces. The conclusion will suggest a solution for the problem of contact surfaces in the gear tooth, by using functional graded materials. In the structure of FGM, the metal phase will provide strength to the gear tooth and the ceramic phase will augment the heat and wear resistance