Performance analysis of photovoltaic passive heat storage system with microencapsulated paraffin wax for thermoelectric generation

The depletion of non-renewable energy sources and negative effects towards the environment push research towards the widespread adoption of renewable energy sources such as solar energy. The main drawback of solar panels is that temperatures above 27°C will result in an efficiency drop of 0.1-0.5%/°C. In previous studies, usage of photovoltaic thermal (PVT) systems was mainly for the purpose of heating water, warming buildings, and drying crops. This research will focus on the usage of a standalone PVT and thermoelectric generator (TEG) system whereby it uses heat extracted from the PVT system for thermoelectric generation. A passive standalone PVT-TEG system design with microencapsulated paraffin wax as a phase change material (PCM) as a heat storage medium was created. The heat stored in the PCM is used as a heat source for thermoelectric generation. To extract the heat from the PV panel, an aluminum heatsink underneath the PV panel is used as a heat absorber to passively extract heat without external power sources. This setup reduces the surface temperature by 22.7°C. Transient thermal analysis and thermoelectric simulation of the system was conducted through Computational Fluid Dynamics (CFD) using ANSYS 2019 software. The error recorded between the experimental and simulation results was 4.2%. This proposed system panel successfully increased the electrical efficiency of the PV panel by approximately 12.8%, where the overall electrical power produced shows a significant increase from 7.7W to 17.7W

Reinventing Aerosol Containment Unit for Use in Medical Operating Theatre

The aerosol containment box or intubation box is medical tool invented to help protect healthcare workers from airborne aerosols while performing procedures such as intubation that are close to the mouth of the patient. The current design of the aerosol containment box is used heavily during the COVID-19 pandemic due to the virus being present in airborne aerosol particles from a patient’s breath. However, the current design has been reported to be flawed in its design aspects. Adding ergonomic considerations into the design is expected to provide improved mobility and better usage of medical instruments. The research conducted analyzed how effective the current design in containing the spread of aerosols from the patient. To execute the research, the current design is modelled in a 3D render using SOLIDWORKS 2020 using dimensions to scale. The 3D model is imported into ANSYS 18.2 to conduct an airflow analysis when a patient cough or breathes to analyses the spread of the aerosols from the patient. The patient coughing was simulated using a nozzle with the boundary space of the model based on the size of the intubation box. The key outcome of the project that the present design is not verry effective in containing aerosol spread as there is still airflow of the particles leaving the intubation box into the environment. The improved design of the intubation box prevents flow of the aerosols into the environment by using suction and seals to close of outlets. The data gained from the study of the aerosol spread proves that there is a higher pressure concentration of the aerosols particles on the walls of the outlets in the existing design in the market as compared to the improved design suggested. This data can help better justify the dimensions and criteria needed to further enhance the current design of the aerosol containment box

Penyediaan dan pencirian nanokomposit epoksi berpenguat getah asli terepoksida

Komposit epoksi berpengisi hibrid OMMT (organo-monmorilonit) dan getah asli terepoksida (ENR) telah dihasilkan dengan menggunakan kaedah penyemperitan berskru kembar pusingan searah. Ujian regangan ke atas sistem epoksi yang dihasilkan menunjukkan modulus Young bagi komposit hibrid epoksi adalah lebih tinggi daripada resin tanpa pengisi dan nilai modulus didapati meningkat dengan peningkatan komposisi OMMT dalam matriks (setinggi 40% peningkatan). Hal ini dipercayai adalah disebabkan oleh sifat tegar lapisan MMT. Sementara itu, peningkatan luas permukaan kawasan antara fasa ekoran kehadiran fasa penambah didapati telah mengurangkan tegasan alah dan terikan akhir komposit hibrid yang dihasilkan. Pemeriksaan mikrostruktur komposit hibrid epoksi melalui TEM dan XRD mendedahkan taburan OMMT dalam matriks epoksi dengan susunan interkalasi dan pengelupasan. Analisis DSC ke atas sampel yang termatang menunjukkan bahawa Tgsistem komposit hibrid adalah rendah berbanding dengan sistem perduaan (E5B dan E5LE). Pengurangan ketumpatan taut silang disyaki merupakan punca penyusutan Tg ini

Effects of liquid natural rubber (LNR) on the mechanical properties of LNR toughened epoxy composite

The effects of liquid natural rubber (LNR) on the morphology and mechanical properties of rubber modified epoxy were investigated. Epoxy composites were prepared in four different compositions of LNR (3, 5, 7 and 9phr) by using twin screw extruder. The samples for tensile, fracture toughness and impact tests were prepared according to ASTM D 638, D 5045 and D 256. The elastomeric nature of rubber can act as energy dissipating centre to cause the ductile fracture for the rubber modified epoxy. They was an obvious increment of fracture toughness where maximum value was observed with 3 phr LNR. A clear increment of impact strength at 3 phr LNR was observed, followed by a small increment at 5 phr and no further increment at 7 and 9 phr LNR. The tensile strength showed a similar trend with impact strength and Young’s modulus. SEM micrographs showed an increment of rubber particle size when the amount of LNR was increased and caused the mechanical properties to drop