HOW HIGH ARE YOU REALLY JUMPING?
Purpose High-jump athletes are not always aware of the exact height they are jumping. They know that they are clearing the height set by the bar, but not their specific height, which may in fact be a record without them even knowing it. The purpose of this project is thus to design and make a device that will enable high-jump athletes to know exactly how high they are jumping. Procedure Background research was conducted and it was confirmed that no similar products are currently available. Possible types of sensors and micro-controllers were then investigated and then both a prototype and model were built to test the concept. Appropriate changes and adjustments were then made to the design until all func-tions were working accordingly. With the assistance of an experienced software de-veloper, a program was designed to communicate the data collected from the sen-sors into a graphical user interface. Results Many variables, contributing to the accuracy of the obtained results, had to be tak-en into consideration. These variables include interference with the sensors, which resulted in less accurate readings, as well as weather conditions. The latter was found not to have as drastic an effect on the results. Conclusion A device that enables athletes to measure the true height they are clearing was suc-cessfully designed and created. This device will thus be able to help motivate athletes by measuring their true capa-bilities.
Building Bridges with Water-The Floating Waterbridge
This paper describes the investigation of a fascinating physical phenomenon called the “floating water bridge”. Despite the fact that water is undoubtedly the most important chemical substance on earth, it is practically ubiquitous and it still represents one of the best explored substances, still not all characteristics are well-understood. There are some phenomena like the “floating water bridge”, which cannot be explained. If high voltage is applied to two beakers, which are arranged close to each other and which are filled with deionized water, a connection forms spontaneously, giving the impression of a floating water bridge. For the experiment discussed in this paper, two beakers with a diameter of 50 mm and a height of 80 mm are filled with triply deionized water. Platinum electrodes are submerged in the center of the beakers, one set to ground potential (anode), the other one on high voltage, up to 25 kV dc. Within the scope of this work, an experimental setup was developed, which enables measuring and demonstrating the most important parameters like voltage, current, length and temperature of the water bridge as well as the mass transfer between the beakers. In addition the correlation between the different parameters and the influence on the water bridge could be estimated. Once the beakers are separated, the bridge remains stable for several hours up to a length of 2.5 cm. With platinum electrodes and no electrolysis observed, a small current (≈300µA), a mass flow from anode to cathode and forces were measured. Pictures, taken with an infrared camera and a new developed method to record "infrared-videos", enabled to visualize the heat flow in the water bridge. Furthermore the conversion of energy and the dependence of charge and mass transfer could be estimated roughly. In the course of the investigations it was also tried to prove the water bridge with other liquids like castor oil, olive oil, a mixture of glycol and water as well as tap water - for some of them for the first time. Supplementary the experimental setup was varied by using different electrodes with different sizes and different material as well as beakers of different sizes and materials. In addition, a qualitative explanation was developed. The results of this work enable a better understanding of the floating water bridge and provide a basis for further research as well as for development of future practical applications. One of these applications could be an improved waste water treatment process.
Synthesis and Characterization of Niobium Nitride Nanowires
This project aims to explore the potential of inexpensive in-situ deposition of niobium nitride nanowires to improve electrical conductivity. Transition metal nitrides are well known for attributes such as superconductivity, high melting point, simple structure as well as excellent electrical and thermal conductivities. In particular, niobium nitride possesses exceptional hardness and high reflectivity, as well as being a stable field emitter, making it well suited to applications as a cold cathode material. Niobium nitrides are formed by the uptake of nitrogen by niobium. This is achieved by the exothermic formation of an interstitial solid solution of nitrogen atoms in the bcc lattice of the niobium. Existing research has established the possibility of preparing niobium nitride by heating niobium in nitrogen or ammonia over a range of temperatures, by heating niobium pentaoxide and carbon in the presence of nitrogen as well as by chemical vapor deposition of other niobium compounds, nitrogen or hydrogen. For the purpose of this study, a two-step process was used for synthesis. The benefits of a two-step process over direct ammonolysis are apparent, from the greater degree of freedom pertaining to parameter determination. Additionally, characterization of niobium pentaoxide nanowires synthesize under similar conditions is also made possible by terminating the reaction earlier. NbN nanowires were synthesized by annealing niobium pentaoxide nanowires at 850 oC for 2 hours. Subsequent characterization was done using Raman Spectroscopy, X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The presence of NbN nanowires via the conversion of Nb2O5 was ascertained by the absence of sharp peaks at 1000 cm-1 for Raman Spectroscopy and XRD plots. Field emission (FE) properties and electrical properties of NbN nanowires were then measured. NbN nanowires were found to have a high turn-on voltage, stable and relatively good field emission characteristics, demonstrating its potential as a cold cathode material. No current saturation was observed for an applied electric field of 0 to 6.0 V/ μm (5). This suggests a low degree of contact resistance for nanowires produced by this method of annealing, since the passage of electrons is not obstructed. Hence there will only be a small voltage drop between the SiO2 substrate and NbN nanowires. Samples containing NbN nanowires were dislodged by ultrasound to form an aqueous suspension of nanowires. A drop of suspension was dripped onto gold-finger substrates, and current-voltage (I-V) measurements of resultant nanowire bridges were taken. NbN nanowire bridges display Ohmic properties, in comparison with Nb2O5 nanowires that are semiconducting. Nanowire bridges obtained by heat-drying were denser and had better electrical properties than those obtained by evaporation to dryness. NbN nanowire bridges display Ohmic properties, in comparison with Nb2O5 nanowires that are semiconducting. Further work would include varying the cooling processes to observe any changes or deformation. Additionally, niobium nitride nanowires can be hybridized with carbon nanotubes (CNTs). A more in-depth comparison between niobium oxide and niobium nitride nanowires is also proposed, along with exploration of the nitrification of other transition metals.
毛細管內液體流速之探討及黏度測量方法之創新
有一次上實驗課時看到鄰桌的同學正以實驗室的毛細管吸吮一瓶\r 葡萄汁，每當他吞嚥時，毛細管內殘餘的葡萄汁竟然以近似等速的狀\r 態降回果汁瓶裡，這似乎違背了重力加速度的常理，是毛細管的影響\r 嗎？還是葡萄汁特有的現象？這與毛細管插入葡萄汁的深度有關嗎？\r 這一連串的問題皆因升學壓力而無暇深究。\r 升上高中的那年暑假，我參加了學校舉辦的資優科學營，在物理\r 實驗課中恰好遇到了以毛細管測量液體黏度的實驗，使我有機會深入\r 思索毛細管內液體流速的問題。這個實驗很不好做，要調整兩個定高\r 容器，使水平毛細管兩端產生固定的壓差，讓流經管內的液體為等速\r 的流動。大家手忙腳亂地操作了近三小時，測出來的黏度不僅和老師\r 公布的答案差距甚大，而且各組同學所測得之結果也大相逕庭，不過\r 我們都體驗到了液體黏度對流速的影響。\r 實驗的誤差為什麼那麼大？扣除人為操作誤差後儀器本身還有多\r 大改進空間？有否更精簡的方法測量黏度？毛細管中液體的流速真\r 是固定的嗎？把毛細管斜置或是垂直架置，流速還會固定嗎？重力不\r 會影響流速嗎？若流速真為固定的，如何控制或改變流速呢？是否可\r 以利用流速來測出液體黏度？\r 由於我對這個實驗的專注，在學校選修的專題課程中即以此為題\r 目做長期的研究，在老師的指導下，我和同組同學不停地查閱有關書\r 籍及整理資料，漸漸研究清楚原理後定出實驗計畫，並開始購買材料\r 與工具，長期地動手實驗及改進，兩年來我們利用毛細管中液體的等\r 速及不等速流動的特性，發展出了兩種既精簡又準確的液體黏度測量\r 法，以下就是整個研究及創作的過程。\r \r \r The viscosity is one of the most important parameters of the fluids. In conventional viscosity experiments, capillary-based viscometers are widely adopted because of their user-ready devices and moderate prices. However, to accurately measure the viscosity, the fluid velocity must be kept constant; otherwise, the fluctuation may cause the serious deviation. Besides, traditional capillary viscometers often require a long time to make the measurement. This research aims at exploring the capillary fluid mechanics and developing accurate and rapid methods to measure the viscosity. In this study, we developed two creative viscosity-measuring methods, the gravity sloping helical structure and the gradational liquid-level difference, and constructed two cost-effective capillary viscometer prototypes accordingly. The gravity sloping helical structure employs a long helical capillary as the flow channel and utilizes the gravity force to keep the fluid velocity extremely constant. The highlight of this method is that we can see the fluid flow through the capillary directly. On the other hand, the gradational liquid-level difference method uses the pressure sensors to precisely monitor the liquid-level difference, which drives the flow in the capillary, and allows automatic measurement of viscosity. Compared with computer simulation, the experimental results agreed well with the theoretical values. The gravity sloping helical and gradational liquid-level difference methods achieve 0.5% and 0.8% accuracy respectively. In addition, the automation of viscosity sensing also greatly facilitates the viscosity measurement. Furthermore, these two methods are both valuable for incorporating into educational purpose and industrial application.
The unknown gene interacts with dll , abdA,Ubx
We operated the misexpression screen between the EP lines and the pattern lines with the genotypes of eq1>dll, eq1>abdA, eq1>Ubx, eq1-GAL4, ey-GAL4 or dpp-GAL4. After the screening, we found that five of these 1,800 strains of filial generation had special phenotypes. It had shorter antennae and defects in the anterior equatorial region of eyes. We used plasmid rescue and IPCR to sequence the certain target gene, and found that it was escargot, abbreviated as esg. To identify when, where and how the overexpression of escargot induces such phenotype, we operated the staining of eye-antenna disc in third-instar larval period of wild type, eq> esg×UAS-GFP and eq>GFP with anti-dll, anti-caspase3 and anti-esg. The result shows that escargot cannot be detected before puparium formation. But the expression of dll, a gene controls the eye development, was reduced in the eye disc. We except the overexpression cause the defect of distal antennae and the anterior equatorial region of eyes mainly in the 3-day-long pupal life.我們用異位表現法篩選出和eq1>dll、eq1>abdA、eq1>Ubx、eq1-GAL4、ey-GAL4或dpp-GAL4 這些pattern lines有交互作用的EP lines。在這1800種的果蠅子代品系中，有五種具有特殊的性 狀。它們具有觸角短化以及複眼前緣中央區有缺刻的現象(形成心型眼)。我們使用質體救援 法以及IPCR的方法來定序這段未知基因序列，發現這是一個叫做escargot的基因(簡稱esg)。 為了了解過分表現此基因會造成何種分子影響，以至於產生此種性狀，因此我們使用 anti-dll 、anti-caspase3 和anti-esg 進行野生型、eq>esg×UAS-GFP 和eq>GFP 三齡幼蟲的 eye-antenna disc的螢光免疫染色。結果在幼蟲成蛹前都沒有偵測到esg的表現現象；不過在eye disc中，控制眼睛發育的基因dll的表現有被抑制的現象。因此我們推測過分表現esg的過程因 該是發生在為其短短三天的蛹期。也就是說，這種表型應該是在化蛹後形成。