The effect of external suction at the dust outlet of a cyclone

Cyclone is one of the most commonly used particulate dust collectors in industries. It employs centrifugal force generated by a spinning gas stream to separate the particulate matter from the carrier gas. However, cyclone is efficient to collect coarse rather than fine particulate size fraction. In this regard, a study was carried out to determine the effect of creating more negative pressure at the storage hopper of a 100 mm diameter laboratory scale cyclone. The negative pressure was created by drawing out a small portion of the gas stream by means of an air pump attached to the storage hopper. Results showed that there was exponentially related between the pressure drop (ΔP) and the amount of gas stream drawn at the storage hopper, but with an increment of 2.6% with suction compared to without. Interestingly, it was observed that more of the fine particulate matter was drawn from the gas stream as the suction flow rate increases. This is due to the suction velocity which exceeds the terminal falling velocities of the fine particles size range. There was a reduction by weight in the fine particle emitted from the cyclone ranging between 14% to 52% by introduction of the suction. The finding serves as a basis for future work in reducing fine particulates from a cyclone separator

Improving students engagement through social media: A case study of a private university in Malaysia using Facebook

This research looks into implementation of Facebook in six different courses covering Science, Engineering and Technology subjects. The initial purpose of using Facebook in the class is to communicate with the students more effectively, as communication through the formal channel (through learn management system) had not been successful. It is expected that by sending two to three notices per week to the students as a gentle reminder for reading material, assignments or even tests, students would be more motivated to engage in the course content. The research results showed that students are positive in using Facebook as an engagement tool. The engagement also encourages their participation in class, and enhances their interest towards the subject content. Features that influenced this engagement are also looked into

Carbon footprint analysis for Sunway University campus

Carbon footprint can be quantified from the emission of carbon dioxide gas (CO2) through human activities, whereby it has impacted the environment. Burning of crude oil as a main source of fuel for combustion to provide energy for transportation and electricity production, releases various Greenhouse gas (GHG), mainly CO2 gas. Hence, a study was conducted at Sunway University to calculate its carbon emission from electricity consumption and transportation usage by campus dwellers (Sunwayians) whereby CO2 equivalent (CO2eq) computations were performed on monthly electricity consumption for the year 2018 till 2019 and the number of vehicles parked within the campus. Behavioural and awareness studies were performed based on survey questionnaires. Results indicated that the total Carbon Footprint from CO2 emission for electricity consumption were 10,369 MTCO2eq and 10,005 MTCO2eq for year 2018 and 2019, respectively while emission from transportations scored 0.383 MTCO2eq per day. The survey showed that a significant correlation between Sunwayians and awareness on sustainable activities on campus. The results of CO2 equivalent for Sunway University would serve as a baseline study for future target setting and strategies in Carbon Footprint for the University management near future

Recent advancements and challenges in flexible low temperature dye sensitised solar cells

Dye sensitised solar cells (DSSCs) have been in extensive development in recent years in the field of solar energy due to its cost-effectiveness, ease in fabrication, flexibility, and being able to be transparent and coloured as well. Two broad categories of DSSCs based on their fabrication temperature are (1) high-temperature DSSCs and (2) low-temperature DSSCs. Although the low-temperature DSSCs (sintered at less than 150 °C) can be flexible and printed on a plastic roll, however, their power conversion efficiency (PCE) is way less compared to their high-temperature counterpart. Research is underway to improve the PCE of low-temperature DSSCs and modules to optimum levels. In this review, an attempt has been made to evaluate different materials and fabrication methods for improved performance of flexible low-temperature DSSCs while also comparing them with the usual rigid high temperature device. Another objective of this study is to critically discuss the progress being made in flexible module development. This review paper would be able to provide comprehensive summary of the recent developments of flexible low-temperature dye sensitised solar cells and modules for reference and also serve as guide for further research in this area

Improved charge transfer through the minimal addition of Pb as a sintering aid to TiO2-based low-temperature dye sensitised solar cell

The poor interparticle connectivity between the nanoparticles architecture of photoanode due to insufficient sintering temperature has been an issue for developing flexible dye sensitised solar cell (DSSC). This issue has led flexible DSSC to yield low conversion efficiency. This research aims to implement lead (Pb) as sintering aid to improve the interparticle connection of the photoanode by using the concept of liquid phase sintering. With low melting point of Pb (327.5 °C), necks were formed at the titanium dioxide (TiO2)–Pb interface that improved the connection and lowered the electronic resistance even at low sintering temperature of 150–250 °C. Morphological studies showed the formation of these necks, while phase analysis indicated the more desirable TiO2 anatase phase was present. Specimens containing 5 wt% Pb in the TiO2 matrix showed the highest efficiency value of 8.73% at 250 °C, which is even higher compared to their high-temperature (450 °C) counterpart by 12.21%. This is due to surface fusion of Pb at a lower temperature, leading to enhanced interparticle contact and reduction in recombination reactions. Further increase in Pb did not improve the conversion efficiency which can be due to high charge trapping sites and layer cracking due to high amounts of Pb in TiO2 matrix

Improved charge transfer through the minimal addition of Pb as a sintering aid to TiO2-based low-temperature dye sensitised solar cell

The poor interparticle connectivity between the nanoparticles architecture of photoanode due to insufficient sintering temperature has been an issue for developing flexible dye sensitised solar cell (DSSC). This issue has led flexible DSSC to yield low conversion efficiency. This research aims to implement lead (Pb) as sintering aid to improve the interparticle connection of the photoanode by using the concept of liquid phase sintering. With low melting point of Pb (327.5 °C), necks were formed at the titanium dioxide (TiO2)–Pb interface that improved the connection and lowered the electronic resistance even at low sintering temperature of 150–250 °C. Morphological studies showed the formation of these necks, while phase analysis indicated the more desirable TiO2 anatase phase was present. Specimens containing 5 wt% Pb in the TiO2 matrix showed the highest efficiency value of 8.73% at 250 °C, which is even higher compared to their high-temperature (450 °C) counterpart by 12.21%. This is due to surface fusion of Pb at a lower temperature, leading to enhanced interparticle contact and reduction in recombination reactions. Further increase in Pb did not improve the conversion efficiency which can be due to high charge trapping sites and layer cracking due to high amounts of Pb in TiO2 matrix

Performance of a Retrofitted Multicyclone for PM2.5 Emission Control

This paper presents on the performance of a retrofitted multicyclone system, which aims to increase the collection efficiency of PM2.5 (i.e. particulate size fraction ≤ 2.5 μm) emission. The multicyclone was retrofitted by extracting 15% and 20% of the total volumetric air flow rate at the dust hopper of the unit using an additional Induced Draft Fan. The total collection efficiency with and without the extraction was measured at various air volumetric flow rates and particulate mass inlet concentration. The results showed that there was a reduction of 12% to 54% depending on the inlet concentration of PM2.5 emission in the stack with compared to without extraction increasing the collection efficiency of the retrofitted multicyclone. The finding suggests that a simple technique of applying gas extraction at the dust hopper of a multicyclone as reported in this study able to increase the overall performance in fine particulate collection

Performance of a Retrofitted Multicyclone for PM

This paper presents on the performance of a retrofitted multicyclone system, which aims to increase the collection efficiency of PM2.5 (i.e. particulate size fraction ≤ 2.5 μm) emission. The multicyclone was retrofitted by extracting 15% and 20% of the total volumetric air flow rate at the dust hopper of the unit using an additional Induced Draft Fan. The total collection efficiency with and without the extraction was measured at various air volumetric flow rates and particulate mass inlet concentration. The results showed that there was a reduction of 12% to 54% depending on the inlet concentration of PM2.5 emission in the stack with compared to without extraction increasing the collection efficiency of the retrofitted multicyclone. The finding suggests that a simple technique of applying gas extraction at the dust hopper of a multicyclone as reported in this study able to increase the overall performance in fine particulate collection

Soil with high porosity as an excellent carbon dioxide adsorbent carbon-rich soil as an effective adsorbent for carbon dioxide

Carbon dioxide, a type of greenhouse gases has drawn world wide's attention as major contributors to global warming and climate change. Thus, several methods have been developed to mitigate this problem such as through adsorption. There are numerous types of adsorbents available, for instance is carbon-based adsorbent that can be synthesised from various type of biomass as reported in previous studies. However, there are very few studies used soil as an adsorbent for gases. Soils are porous medium developed in the uppermost layer of Earth's crust which are available in several forms, abundance and cheap. In this study, three types of carbonised soils were used as carbon-based adsorbent to investigate its adsorption capacity for carbon dioxide. Influence of moisture content in this study is negligible as it is too low. Due to the nature of raw materials used, ash content for all sample was incredibly high which almost all exceeded 90%. Determination of densities by pycnometer showed that carbonised soil 2 has the lowest particle and bulk density of 2.4802 g/cm3 and 0.5248 g/cm3 respectively. Then the adsorption capacity of each sample was determined by sorption measuring instrument with magnetic suspension balance. Results showed that carbonised soil 2 with high surface area, pore volume, and small pore size has the highest adsorption capacity of 6.4 mg/g at 25C under atmospheric pressure. Therefore, soils exhibit prominent potential to be developed as carbon dioxide adsorbent with desirable properties

Effect of lead sintering aid to TiO 2 photoanode for flexible dye sensitized solar cell

The commercial application of flexible dye sensitized solar cells (DSSCs) is somewhat limited due to the devices’ low conversion efficiency. The low sintering temperature in preparing the photoanode has caused poor interparticle contact, low charge transfer and low efficiency. Hence, this research aims to improve the interparticle contact of titanium dioxide (TiO2) photoanode with the novel use of lead (Pb) nanoparticles as sintering aid at low temperature. TiO2-Pb composite photoanode was prepared with different composition of Pb including 4% and 7% sintered at low temperature of 250°C. The research discovered that TiO2 photoanode mixed with 4% Pb composition showed the lowest charge transfer resistance (RCT) even at low sintering temperature. The RCT value was even lower than a commercial TiO2 photoanode sample that was sintered at 450°C. The addition of Pb sintering aid has improved interparticle contact in the photoanode via the neck formation at the TiO2-Pb interface and enhanced charge transfer despite the low temperature. The prepared photoanode samples displayed potential in developing highly efficient flexible DSSC