A New Design Of Conformal Cooling Channels (Milled Groove Square Shape) In Injection Molding Processes

In materials processing, quality and productivity are notably important and must be controlled for each product type produced. In the injection molding process, quality is measured as the extent of warpage of molded parts and productivity is measured in terms of the molding cycle time. This paper presents a new design of milled grooved square shape (MGSS) conformal cooling channels, which provide more uniformity in cooling with a larger effective cooling surface area compared to circular and other types of cooling channels with a similar cross-section. This study examined the warpage of molded parts and the cooling time, which affected the molding cycle time.

A case study involving a front panel housing was performed, and the performance design of the MGSS conformal cooling channels were compared to that of conventional straight-drilled cooling channels by simulation using Autodesk Moldflow Insight (AMI) 2013 and validated experimentally. The simulation and experimental results are in good agreement for the MGSS conformal cooling channel, which was able to reduce the warpage and cooling time of the molded part by 13.95 to 54% and 64.83%, respectively, compared to straight-drilled cooling channels.

Keywords:Injection Moulding Process; Polymers; Conformal Cooling Channels

Novel GeoGreen Coat for Surface Protection

Due to increasing global CO2 emissions, geopolymer technology became the new interest of researchers from all over the world. Geopolymer based coating is not only a simpler economic alternative, but also provides a greener solution as compared to existing coating such as sodium silicate paint and OPC based cementitious coating material.
Geopolymer source materials such as fly ash, kaolin, silica sand and white clay is studied and has potential to be use as geopolymer coating. Coating application has been studied to elevate the performance of both metallic and non-metallic substrates such as aircraft, marine, concrete and pipeline system. Hence, these coating process can be apply to the pipeline system in order to reduce the risk or lack of workability of non-metallic substrate such as glass fiber-reinforced epoxy (GRE). Glass fiber-reinforced epoxy (GRE) composite is one of the most widely used glass reinforced plastics (GRP). They are used extensively in the marine, building, automotive industries and widely used in pipeline industry. As the use of these material increases, so does the need to define reliable design limits in terms of performance.

Thus, Novel GeoGreen-Coat was made to create an innovative coating application in term of advancing the mechanical performance of geopolymer coating on non-metallic substrates by using new source material which provides huge advantages such as excellent mechanical properties, abundance, low cost, and environment friendly.

Keywords: Geopolymer, Coating, Kaolin, GRE Pipe, Wood, Alkaline Activator

Rogowski Coil Sensor using ABS Material for Smart Online Partial Discharge Location Technique

In high voltage (HV) engineering, partial discharge (PD) is an electrical discharge or spark that bridges a small portion of the insulation. PD resembles a cancer in the insulated cable before the fault happens. The conventional technique experience severe limitation when it comes to on-line monitoring due to the influence of background noise that distort the pure PD signal, absence of non-intrusive sensors and processing facilities. Moreover, the limit in the detection of frequency range PD especially in HV cables due to the attenuation of high frequency PD signal. Low detection in term of sensitivity and frequency for the sensor are fundamental limitation the PD detection which the major concern in insulation monitoring. The PD sensor must be installed in existing network during operation and may not risk of failure for the power grid. High frequency current transformer (HFCT) has traditionally been used well for this measurement because of its additional ability to produce higher outputs needed by electromechanical equipment. The problems like saturation, size, weight and high cost are some factors which limits its use if frequent monitoring is required. Moreover frequency response to PD signals by sensors is important are to be improved. Research on an incoming non-conventional current sensor which is coreless inductive sensor has raised great interest. This project is a new design of Rogowski coil (RC) sensor as a cost effective and efficient (high sensitivity and wide bandwidth) for PD detection in medium voltage (MV) line. The design of RC sensor using Marker Bot Replicator 2X 3D printer using Acrylonitrile Butadiene Styrene (ABS) filament makes the design of PD sensor more accurate in term of geometry. The ABS material is selected based on its characteristic to provides more robust, durable, lightweight, withstand to high temperatures and accurate geometry to the sensor. It is preferred plastic for engineering product in professional application.

Various types of virtual surgical instruments are available in the simulator for users to choose when performing particular surgical procedures. Since two haptic devices are equipped for the surgical simulators, surgeons and medical trainees are able to switch the tools between both hands by referring to the graphical user interface (GUI) that is created in the platform. Visual feedback such as tissue deformation and force reaction movements of human eyeball are implemented into the simulator along with haptic feedback that gives tactile sensation when collision is detected during the simulation. Users are able to sharpen their skills on specific surgical procedures by referring to the performance evaluation system embedded in the simulator. Concerns in phacoemulsification cataract surgery such as position of corneal incision and damage on posterior capsule during phacoemulsification are embedded in the proposed surgical simulator to improve the awareness of ophthalmologists in avoiding surgical trauma and retinal detachment. Besides that, graphical surgical guidance and evaluation in the simulator are able to assist ophthalmologists along their surgical training.

Keywords: Partial discharge, High Voltage Insulation, Medium Voltage Distribution Lines, Sensors, Smart Online Partial Discharge Location Technique.

Radio Engineering Designs in Internet-of-Things

Future wireless communication systems such as Fifth- Generation (5G) wireless network should be capable of accommodating higher data rates than the current systems owing to the advent of various multimedia services. One of the promising solutions in the 5G network design is massive Multiple-Input Multiple-Output (MIMO) network, which deploys large scale of antennas (more than one antenna) at both ends of the communication link. Since the base station can handle hundreds of simultaneous users now, that is not enough to accommodate the billions of new devices that will hook into the Internet-of-Things (IoT). Therefore, the radio system design for IoT becomes more complex than before. There has been a lot of interest on addressing the challenges of electromagnetic interfaces, antenna design, signal and power integrity, and high-speed circuit design, while simultaneously addressing power, performance, size and cost constraints.

Keywords: Antennas, MIMO, propagation, advanced wireless communication system, 5G wireless network.