Inclined Sedimentation of Suspensions: Theoretical and Experimental Investigation into the Boycott Effect
The Boycott Effect is a phenomenon where sedimentation rate can be increased by tilting the container which holds the suspension, making it a way to increase the efficiency of the process without additional energy input. This makes the Boycott Effect valuable in speeding up and optimising a multitude of industrial applications such as wastewater management and food processing, all of which employ sedimentation to separate particulate matter from the fluids in which they are suspended in. Thus, it is imperative to model the Boycott Effect accurately for a wide range of cases, including arbitrary shaped containers and suspensions of various concentrations without the need to run costly, computationally expensive numerical simulations. In this project I investigated the inclined sedimentation of suspensions both theoretically and experimentally. Experimentally, two image tracking programs were created and tested out on my own experimental videos. I demonstrated the use of a novel method for making use of the Beer-Lambert Law to optically keep track of local concentration of suspensions. This method allows more information to be gathered about the sedimentation process in a very low-cost, non-equipment intensive or invasive way. Theoretically, I expanded upon the well-known analytical 2D PNK theory by accounting for concentration-hindering and sediment build-up effects, as well as the geometrical theory for 3D cylindrical geometries. All parts of the theoretical model were verified with experimental data and shown to have good agreement. (233 words)
SeaUVeed Succeed
In the first part of this project, distilled water and 95% ethanol were used to extract ultra-violet(UV)-absorbing and anti-oxidizing compounds from different types of algae including kelp, wakame, sea grape and nori. Activated charcoal was used in attempt to purify the extracts and removed excessive pigments. It was found that the charcoal was more effective in adsorbing pigments from ethanol extract in which up to 80 to 100% pigments could be removed. The UV-absorbing and anti-oxidizing properties of the algae extracts were also studied. All algae extracts showed significant UV-absorbing and anti-oxidizing properties. In particular, extract formed by using 3 g kelp powder in distilled water could significantly reduce 50% UV intensity and react 96.5% DPPH solution which acts as a source of free radicals. In the second part of the project, three applications of algae were explored in details. Firstly, it was found that kelp, wakame and nori extracts by using over 2 g of algae in 30 mL olive oil could absorb UVA and UVB by over 90%, which is comparable to the performance of zinc oxide, a common ingredient in commercial sunscreen products. Costs of preparing the sunscreens were also compared. Except for wakame extract, all other extracts were cheaper than using zinc oxide. Moreover, the kelp extract was found to maintain its UV- absorbing and anti-oxidizing abilities after at least 30 days of storage under room conditions. Lastly, sodium alginate was successfully extracted from kelp with a product yield up to 30%. The alginate solution was then used to form a calcium-alginate protective coating on plastic slides to reduce UV intensity by up to 50%. This aims to apply on nails or fingers during UV nail gel polish to protect against UVR.
Fabrication of Highly Efficient and Cost-effective Tandem Dye-sensitized Solar Cells for Building Integrated Photovoltaics
In recent years, there has been an extreme rise in population and economic development, which requires a great demand for energy worldwide. Global energy consumption has been increasing nearly every year for over half a century [1]; it is rapidly rising in the form of nonrenewable energy, such as coal, oil, natural gas, and fossil fuel. Fossil fuel overreliance has resulted in a dramatic rise in atmospheric carbon dioxide (CO2) concentrations.
大「逆」不道—局部逆境下植物體內傳訊與物質分配機制
When a leaf of a plant encounters stress, how does the plant convey the stress signal to other tissues and manage nutrient distribution? This field of study has been largely unexplored. However, the unique interconnected frond structure of Lemna trisulca, along with the use of a divided Petri dish, is very suitable for handling localized stress and investigating the mechanisms of intracellular signaling and nutrient distribution. Research has shown that when the mother leaf experiences localized stress, it releases healthy daughter leaves to minimize collateral damage to the daughter leaves. Conversely, when the daughter leaves face localized stress, the mother leaf chooses to retain them and continues supplying them with nutrients to support their survival. In-depth studies revealed that stressed daughter leaves accumulate Reactive Oxygen Species (ROS), triggering nutrient distribution by sending a distress signal to the mother leaf. This prompts the mother leaf to use Ca2+ as a signaling molecule to deliver nutrients to the daughter leaves. Selective detachment is regulated and triggered by the interaction between Ca2+ and ROS within the mother leaf. When the mother leaf undergoes stress, Ca2+ acts upstream to induce ROS accumulation at the nodes, sending a unidirectional detachment signal to the daughter leaves. This causes ROS accumulation at the daughter leaf nodes, inducing detachment and thereby reducing the collateral damage the daughter leaf could experience due to the mother leaves.
On the Application of Inequalities Containing Sums of Minimum/Maximum of Numbers
Retail inventory management is a crucial part of many businesses due to the high profit associated with it as well as the uncertainty around it, especially for industries with short production cycles and a complex supply chain.Proper management ofretail inventories can lead to decreased inventory costs, prevent spoilage and obsoles- cence, and improve customer satisfaction, all of which lead to increased profits for the company.Inthispaper,wefirstproposeextendingawell-knowninequalityandtry to generalize it to other conditions and similar inequalities.The inequality involves multiple variables and how the maximum/minimum values of a subset of the numbers compare to the maximum/minimum values of the whole set of numbers.Our main contribution is applying such inequality in inventory management to help estimate the total cost of inventory management, which would allow us to determine the shutdown pointforaspecificcompanyusingthegeneralizationsoftheinequality.Lastly,weshow thatourestimatesarereasonableandproposesomefutureareaswheremoreworkcan be done.
探討藉由隧道奈米管(TNTs)傳遞Chromogranin-A對神經母細胞瘤細胞的影響及其相關機制
Previous research observed increased TNTs formation between hypoxic and normoxic neuroblastoma cells, aiding hypoxic cell survival. CHGA was identified as a potential factor in this process. This study compared CHGA expression and whether CHGA exists in TNTs in five cell lines, with SH-SY5Y showing the highest levels, followed by SK-N-BE(2)C, while the other three showed lower expression. Future studies will focus on the impact of CHGA on cell survival and its mechanisms.