How to spill your coffee
We all do it – walk along with a cup in hand, and carelessly spill it. While it’s usually more annoying than anything else, it happens to affect almost all of us, and little is done to minimise the likelihood of it occurring. So my aim was to explain the physics behind why we spill drinks when we walk, and to investigate how we can minimise the likelihood of this occurring. I broke this investigation into two distinct parts, explaining the system of the cup, and explaining the effect of walking. From initial observations, it was clear that the cup was a resonating system. Like any resonating system, the cup has a natural frequency. When the cup is oscillated – moved back and forth – at near this frequency, the size of the liquid oscillations is very large. This is because the acceleration is in phase with the motion of the liquid, so in each cycle maximum energy is input into the system. In my investigation I experimentally measured this natural frequency, and created a mathematical model to explain this frequency. It was also found that as the size of liquid oscillations in the cup increases, so does distortion of the fluid surface, possibly enabling spilling. To systematically analyse the effect of walking, I had subjects walk on a treadmill, so walking surface and speed were controlled. However, I also needed an accurate way of measuring the motion of a carried cup. Firstly, I tried to use video analysis; however I found this far too imprecise for measuring small changes in velocity of a cup. In the end I used a smartphone to record the acceleration of a carried cup, as acceleration is what causes the movement of liquid in a cup. This allowed surprisingly accurate measurements to be made, and allowed both the size and frequency of the acceleration to be recorded. In order to relate the system of the cup and the oscillation provided whilst walking I conducted a qualitative experiment into the effect of stride frequency on the likelihood of spilling. When stride frequency was very close to the natural frequency of the cup, spilling occurred almost instantly, while it did not occur if stride frequency was much higher or lower. In the end, my research showed that to minimise the likelihood of spilling your drink walk slowly, use a narrow cup, focus on walking smoothly, and fill the cup well below the rim. Despite this, some people happen to be much smoother cup carriers than others, likely due to their individual biomechanics. And, if you really don’t want to spill your drink, you can always use a lid.
A Backpropagation Neural Network Model on Precipitation Forecasting in the Philippines
Backpropagation neural networks were used to forecast daily rainfall with minimal error for Metro Manila in order to have an inexpensive way of accurately predicting weather. Calamities brought on by heavy rainfall have caused great economic, infrastructure and human loses. Neural networks have the ability to discern complex patterns in noisy data; this makes it a viable method for weather forecasting. Daily precipitation, humidity, rain indication, sea level pressure, temperature and maximum sustained wind speed for January 2000 to December 2010 were acquired from the Philippine Atmospheric Geophysical and Astrological Services Administration. The neural network made use of Python 2.7.2 and the backpropagation program by Neil Schemenauer (python.org). It considered different neural network architectures with a total of 2844 data sets for training and 708 data sets for testing. Each neural network’s accuracy was measured with a graph of the actual and predicted values, correlation coefficient, and root mean square error. It was observed that the neural network with architecture 5-8-1 yielded the most accurate results as it had the highest correlation coefficient of 0.48599 and smallest root mean square error of 14.84. It was also observed that the trends of the predicted values followed that of the target values. This suggests that it is possible to create a neural network with a moderate correlation given daily weather data. It is recommended that further researches make use of hourly data instead of daily data for more accurate results. Other variables, which might affect rainfall, not in this study should also be considered. This research could aid in the anticipation of calamities and the decision making involved in shipping, fishing and aviation industries.
A Novel Selection Process for the Conversion of Conventional Bacteria into Electrotrophs
The redox reactions of bacteria metabolism have been extrinsically studied. These mechanisms allow certain types of bacteria to be able to synthesize extremely valuable extracellular byproducts. Other types of bacteria are able to extract toxic metals from water by donating electrons directly to those aqueous metal ions, thus turning them into solid precipitates. However, the problem of these microorganisms is that their efficiency rates and production speeds are exceptionally low. This study focuses on the properties of electrotrophs, which are bacteria that can feed on pure electrons directly from an electrode (Rabaey et al 2010). Compared to normal organic-feeding bacteria, electrotrophs direct the majority of the electrons obtained to the production of metabolic byproducts (Nevin et al 2010). Therefore, when electrotrophs are employed in bioelectrochemical systems (BESs) their metabolic redox reaction efficiency rates are dramatically increased. This makes it possible to produce large quantities of valuable compounds such as hydrocarbons, plastics and medicine or efficiently remediating the environment (He et al 2016). Moreover, the usage of electricity as an energy source compared to conventional organic substrates is immensely cheaper (Rabaey et al 2010). However, not all bacteria are electrotrophs nor do all electrotrophs have favourable metabolic traits. Thus, there is a need for a novel procedure to turn conventional bacteria into electrotrophs which is a crucial step to making the BES an aggressive competitor in the sustainable energy industry.
A New Generation Colorimetric Method for Lead Analysis: APTAMER MODIFIED GOLD NANOPARTICLES
Lead is a toxic element which is used in the production of chemicals, dyes, accumulators and various industrial areas. It may cause complications even extended to death when it is taken consistently in high amounts. Lead poisoning is in the first place among the occupational diseases. It is gaining importance to develop new and sensitive methods for lead analysis. Because lead poisoning can progress without any symptoms and poisoning level (10µg/dL) is low. Disadvantages of the systems used for lead analysis are such as longer detection time, being expensive and difficult to implement. The aim of this project is to develop a new generation method in order to detect lead in blood, based on aptamer modified gold nanoparticles. We detected the lead in terms of color change obtained in gold nanoparticle solutions, with composite biochemosensor that is prepared with 20 & 80 nm sized gold nanoparticles and TBA(Thrombin Binding Aptamer). While immobilizing TBA to the gold nanoparticles, we benefitted from the magnificent surface affinity of the –SH (Thiol) groups that modified to the TBA. Gold nanoparticles that are used in development of our biotechnological method do not stimulate the immune system. The preparation of aptamers in completely sterile medium provides us to use our system in the lead detection of blood. Our method can also be used in the lead detection of mediums such as waste water, food and soil. We have developed a biochemosensor that can be used to detect the presence and absence of Pb2+ by taking into consideration the toxic effect in the human body. Also we detected the presence of lead colorimetrically, in low concentration levels and wide interval values of 4.4 – 11 µg/dL. The developed system is first that; it provides TBA to be used with its complimentary sequence detects the presence of lead colorimetrically and can be used in physiological media such as blood. Also our system can detect lead in amounts that are lower than the poisoning threshold.
Antiviral Therapy for Hepatitis C Virus (HCV): Black Mustard Seeds
Hepatitis C Virus (HCV) is an RNA virus, which is considered the main cause of progressive chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. The number of the patients who are infected with this sleeping virus is increasing rapidly every year, as the unsuitability of the current therapy – interferon α and ribavirin – for most of the genotypes is the main cause of these high rates. Hence, the recent researches are focusing on finding out a new immunotherapy to affect this virus. In this research work, Black Mustard (Brassica nigra) has been used as powdered spice samples to prepare aqueous extracts; One of the included phytochemicals in the black mustard; glucosinolates and their hydrolysis products, was proposed to be used for the HCV patients to prevent the virus progression. Also, the Isothiocyanates are shown with chemotherapeutic and anti-tumor properties. Moreover, some of the structure-related isothiocyanates have the ability to induce the enzyme paraoxonase-1 (PON-1) that is considered hepato-protective agent against liver impairment, inflammation, fibrosis and liver disease mediated by monocyte chemoattractant protein-1 (MCP-1), and is thought to affect the entry of the virus into the hepatocytes. The effect of the black mustard and the produced myrosinase enzyme on the HCV RNA replication is still unknown. In conclusion, the black mustard is thought to affect the progression and the fluidity of the HCV envelope resulting in impairment of viral binding and fusion.
阿里巴巴轉盤問題
本作品為環球數學城市競賽的考題之推廣（ International Mathematics Tournament of the Towns, Senior A-Level Paper, Fall 2009, No. 7 ），然而此題目本身比較接近Scientific American （ Feb 1979 ）中 Martin Gardner 的文章 The Rotating Table 所提出的問題。 而此問題的多邊形版已被數學家解決(Ted Lewis & Stephen Willard, 1980, The Rotating Table,Mathematics Magazine, 53,Page 174-175.)。然而此份作品採用簡潔的初等數學歸納法證明了原本的多邊形情形，且專注於探討條件改變為m=n-1時的多邊形情形。 m=n-1時的情形是前人所沒有做出結果的，且m=n-1的情形遠遠比m=n 的情況來得複雜多變，其中估計上下界所使用的許多組合技巧相當特別。然而其中當n為3 和5的倍數時有比較特殊的情況，這一個部分僅能給出目前得出的k值上界。而其他情況則能夠找出所有的k值。
費馬多邊形數定理之延伸探討
本研究旨在研究費馬多邊形數定理(任意非負整數必可表成k個k邊形數的和)的一般化情況，也就是說，任意非負整數是否能表成給定的二次多項式數列中所選取的γ項和。以數學模型敘述，就是探討對一個已知的二次多項式an2+bn+c，是否可找到一正整數γ，滿足∀x∈N∪{0},∃α1,α2,…αγ,使得x=∑γi=1(aαi2+bαi+c)。 本作品主要探討若此探究模型存在，那麼數列〈an 〉的一般式an2+bn+c與γ值之間會存在什麼關係，並期望能運用一個簡潔明瞭又一般化的數學式表示。本文亦提供另一個數學模型，探討γ值與某些特殊係數a,b,c之間的關聯性。而本文探尋[a/2]n2+[b/2]n+1,a∈N,b∈Z,a+b≡0(mod 2)(此為本文主要探討的二次式)，求得此二次式所對應之γ值的方法為先令p=[2a/(a+b)]+2，再藉由所建立的模型二，求出[(p-2)/2] n2+[(4-p)/2] n的γ值，接著再用所建立的模型一來求得[a/2]n2+[b/2]n+1的γ值，進而依循此方法最後得出任意形如[a/2]n2+[b/2]n+1的二次式之γ值。