Resin infusion Research Papers - Academia.edu (original) (raw)

Controlled and precise delivery of fluid is one of the essential requirement in many fluid flow applications such as micro fluidics, Micro Electro Mechanical Systems, micro-machining and in medicinal biological systems. Such deliveries are commonly achieved using syringe pump which generally employs syringes driven by an electric motor. In this work a syringe pump is operated with a Raspberry Pi-System on Single Chip, which is more user friendly than a control with an ordinary microcontroller. It runs on Linux platform which is easy to code and control using Python language. The syringe pump is actuated by stepper motor which has 200 steps per revolution so that precise flow rate is possible compared to other electrical actuators. The stepper is connected to a Dual H-Bridge L293D motor driver, which in turn is powered through the GPIO (General Purpose Input / Output) pins-an integral part of the Raspberry pi. Lead screw mechanism is used in this work to transmit rotary motion of the motor to linear motion of syringe. The pitch length travelled by the screw is minimal and controllable, resulting in a precise flow rate of the fluid which is measured experimentally.

For any operations, the patient being in an anesthetic condition is must. The patient won't feel any pain during the medical procedure using anesthetics. The impact of the anesthesia should be there how long the operation goes and for that, the specified time intervals are administered. What happens if it is not administered at that particular time interval? It will be creating serious health problems and to overcome such unfavorable situations this project has been designed to develop an automatic anesthesia controller using Arduino Uno. The anesthetist can set the amount of anesthesia to be given to the patient. Using the switch panel, the anesthetist can start the process and once the start signal is received by the Arduino Uno it controls all the system, sends a signal to the motor driver to switch on the motors and start infusing the anesthesia. A minimum amount of anesthesia will be injected to the patient body, while doing this the heartbeat will be monitored. After administration it will check whether the heartbeat count is normal or not. If normal, then the second dose of the medicine will be injected. If the heartbeat shows any abnormality then the administration will be stopped and will notify the doctor and continue only after everything becomes normal. Additionally, temperature parameters are checked by corresponding sensors. The keypad switch is also used in case of any urgent manual operation that can be controlled by keypad.

- by Mohd Azuan Mohd Azlan
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- Image Processing, Void, Resin infusion, Fiber Reinforced Polymer (FRP)

In general, permeability measurement results show a strong scattering according to the measurement method, the type of test fluid and the fluid injection condition, even though permeability is regarded as a unique property of porous medium. In particular, the discrepancy between the unsaturated and saturated permeabilities for the same fabric has been widely reported. In the literature, relative permeability has been adopted to model the unsaturated flow. This approach has some limits in the modeling of double-scale porosity medium. We address this issue of permeability measurement by rigorously examining the mass conservation condition. Finally, we identify that the pressure gradient is non-linear with positive curvature in the unsaturated flow and a misinterpretation of pressure gradient is the main reason for the difference between the saturated and unsaturated permeabilities of the same fiber reinforcement. We propose to use a fixed value of permeability and to modify the mass conservation equation if there are air voids, which are entrapped inside the fiber tow. Finally, we also suggest some guidelines and future perspectives to obtain more consistent permeability measurement results.

- by Chung Hae PARK and +1
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- Process Modeling and Simulation, Natural fibre composites (Engineering), Porosity, Permeability

The demand for thermoplastic composites is continuously increasing because these materials offer many advantages over their thermoset counterparts, such as high toughness, long storage time, easy repairing and recycling, and ability to be thermoformed and heat-welded. However, the manufacturing of thermoplastic composite parts using liquid composite moulding techniques (e.g. resin transfer moulding, vacuum assisted resin transfer moulding …) is often tricky in the case of melt processing where high temperature and pressure should be chosen to impregnate the fibre reinforcement because of the high melt viscosity of thermoplastics. These issues may be overcome by means of reactive processing where a fibrous preform is first impregnated by a low viscosity mono- or oligomeric precursor and the polymerization of the thermoplastic matrix then occurs in-situ.
This article draws a state of the art on the manufacturing characteristics of continuous fibre reinforced acrylic-based reactive thermoplastics (e.g. polymethymethacrylate (PMMA) such as Elium), which are becoming more and more popular compared to other fast curing thermosets and thermoplastics for in-situ polymerization. Techniques for the in-situ polymerization of methymethacrylate monomers, characterization and modelling of the rheological properties and polymerization kinetics, and some manufacturing related issues such as polymerization shrinkage are reviewed. Particular features of the use of reactive PMMA in different manufacturing techniques of continuous fibre reinforced composites and potential industrial applications are also introduced. Finally, some perspectives for the academic research and industrial development are proposed.

- by Patricia Krawczak
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- Composites, Advanced Manufacturing, Composite Materials, PMMA