物理與天文學

The study aimed to compare the electricity generated from the fruit extracts of calamansi, camias and starfruit. Unripe fruits were extracted and varied percentage compositions of each extract were prepared.Wires wereconnected to a multi-tester (voltmeter or ammeter) to measure voltage or current that passes through. Results revealed, that amount of voltage and electric current generated are its lowest reading at 25% and are its highest reading at 100%. Nonetheless, of the three fruit extracts, it’s the calamansi that has the highest amount of voltage generated of0.97 volt while camias has the highest amount of electric current generated of 13.98 mA. Using ANOVA at 0.05 level of significance on the amount of voltage generated among varied percentage compositions of three extracts. However, there’s a significant difference on the amount of electric generated among varied percentage compositions. Results of ANOVA statistically signify that the three different extracts could either be used as a source of voltage and that camias extract should be preferably used over the other two fruit extracts in generating electric current. In all compositions, produced voltage is between 0.88 and 0.97 volts and current is between 3.28 and 13.98 mA. These currents produced are not enough to turn on a small light bulb having a smallest voltage capacity of 1.2 volt, but can be able to turn on a light-emitting diode (LED) that require such amount of current.

藉由結合液晶與奈米線，本研究設計出新型的光電元件，我們發現這些新設計具有先前元件很難達到的新穎特性。首先，我們研究液晶分子與一維磁性奈米線之結合，很有趣的是磁性奈米線在液晶元件內，會沿著液晶方向作整齊排列，更重要的是經由一外加電場，即可調控磁性奈米線之磁場方向。藉由電場調控磁場，是很久以來許多科學家追求的目標，然而成效不彰，本研究提供了一個簡便的方法，克服了長久以來的障礙。第二個例子，我們研究液晶分子與一維半導體奈米線結合之元件，我們證實了半導體奈米線所發射瑩光之電場偏極方向，可以經由外加電場來調控，這個特性對於資訊科技的應用，將很有用處。本研究所觀測到之結果，皆可利用下列事實來理解，奈米線具有很大的表面積，因而增加了與液晶分子之交互作用，經由此增大的交互作用力，奈米線會沿著液晶分子方向排列。值得強調的是，本研究利用了已成熟的液晶顯示器技術，其未來應用性將有很大潛力。New devices based on the composites of liquid crystals and one dimensional nanowires have been designed, fabricated, and characterized. It is discovered that these novel devices own interesting properties that are very difficult to be obtained by conventional ones. As the first example, the liquid crystal device with built-in one dimensional magnetic nanowires has been studied. It is found that the magnetic nanowires can be well aligned along the orientation of liquid crystal molecules. Quite interestingly, the direction of the magnetization of magnetic nanowires can be easily manipulated by an external electric field at room temperature. The phenomenon of electric manipulation of magnetization has been studied since nineteen century, but the achievement is rather limited. Here, we provide a convenient alternative to overcome the long quest search. For the second example, the liquid crystal device with built-in semiconductor nanowires has been investigated. We demonstrate that the polarization of the emission arising from semiconductor nanowires can be easily controlled by an external electric field, which is one of the basic requirements for information technology. All of our observed results can be well understood in terms of the inherent nature of a large surface to volume ratio of one dimensional nanowires, which induces a strong interaction between embedded nanowires and liquid crystal molecules. Therefore, the nanowires can be driven along the orientation of liquid crystal molecules. It is stressed here that our newly designed devices are based on the well established liquid crystal display technology and therefore their practical application can be realized in the near future.

本實驗將小型塑膠圓片置於水中釋放模擬落葉的運動模式，發現圓片與水平之夾角呈現週期性變化，變化範圍會隨著時間改變。在運動幾個週期後，變化範圍會被限制，此時為穩定狀態。在水中加入鋁粉以觀察圓片運動時流場的變化，提出分流模型與最短時間原理，發現此模型可以解釋圓片的轉動機制。

本實驗主要是透過及程式模擬分析，探討變形之阿特午機 在一般狀況下及過渡期 的運動過 程。透實驗，我們找出不同的初始條件對於運動結果影響 ，如質量比、繩長 等。我們透過實驗和數值分析建構變形之阿特午機的模型 。因為 摩擦力和空氣阻對於運動 的影響皆不可忽略，因此 我們 也設計阿特午機和鉛直圓周運動的 實驗以求出兩個影響因素參數， 並將其結果統整於理論分析中。這份研究有助我們了解力學的過程目前我們 也正在進行更詳細的數值分析， 我們也希望能在之 後將變形之阿特午機的理論與實驗結 果合，預測不同變因的實驗結果。

本研究提供一種低成本且高產率的奈米泡泡製備方法，我們以去離子水注入氮氣製程製備成溶液，再藉超音波震洗機(sonicator)高速振動來製備奈米泡泡。在實驗中我們藉由控制不同的震動時間及實驗參數，可製作出不同尺寸的奈米泡泡，藉此可找出奈米泡泡的臨界尺寸。藉由這種方法我們可成功製作出100nm以下的奈米泡泡。另外我們發現隨著振動時間增加，泡泡的尺寸會逐漸減少，呈現明顯且有趣的尺寸效應變化。實驗結果顯示以當離子水溶液以氮氣飽和20分鐘並以超音波振動30分鐘時，可製作出最小臨界尺寸為23nm的奈米泡泡，此一奈米泡泡尺寸為目前所觀察到最小尺寸的奈米泡泡。我們也對不同實驗條件下所觀察到的尺寸效應，提出分析及探討，以期未來能對奈米泡泡的尺寸現象有更多瞭解。而利用此一方法來製作奈米泡泡有別於傳統方法，除了可製作出高產率且高穩定性的奈米泡泡之外，更可進一步改善一般傳統方法製作泡泡因為表面張力造成的影響，其泡泡尺寸只能達到微米(10-6)等級。而我們的方法可將泡泡的尺寸縮小至數十奈米等級，將有助於未來奈米泡泡於生化領域以及醫學上的廣泛應用。

本實驗乃研究超順磁性流體薄膜在通入垂直場後磁顆粒的動力學過程，以及排列的結構、磁鍊的幾何性質。我們使用了兩種創新的方法，分別是改良傳統磁性流體製造方法，避免磁性流體因凝聚而造成干擾；另一個是除了以往以電場或顯微鏡探討磁鍊的性質，使用Rayleigh scattering以及光遮蔽的方法，以CCD量測雷射透射光強度的時變率，改變不同變因(磁場大小、磁性流體樣本厚度、磁性流體濃度)，由於其結構性質影響了透射光強度，故分析透射光強度與諸變因間的關係，並與顯微鏡下的觀察結果比較，做出磁致散射動力學過程詮釋。

靈光乍現：弦的震盪由直到彎，從單懸到雙懸迴盪不已，共振駐波顯現半波長的微妙變化。故佈疑陣：曲弦振盪、共振頻率、弦上張力、半駐波長，玄機重重。 高潮迭起：推翻同一弦上所受張力相同，得知曲弦曲度不同所受張力亦不等的真相。 明天過後：重現曲弦程度，知彈性係數迴旋，將曲弦駐波性質變化摸透透。 ;Inspirations: Vibrating the string of thing bar from longittudinal to transverse; from both arm to single arm; from the waves of the string to the mystery ofλ/4. Battle: Resonance frequency, string tension force, half stationary wave, questions flying everywhere. Revolution: Overturn the theory that the tension force on the same string equalizes everywhere by measuring the length of eachλ/2 ; proof that the tension force enlarges from the top of the string to the end because of the gravity of the string ; Calculate the constant of the difference between the length of the incomplete wave on the end andλ/4 / the last completeλ/2. Proof that the constant is decided by the thickness of the string rather than the length of the string ; Finding the fact that the number of completeλ/2 on the same string equals no matter where the vibrating spot is.

本計畫採用數值模擬進行研究，撰寫一維電漿的物理程式來瞭解電漿孤立子在不均勻背景中的演化。我們於去年的計畫中，驗證了這個模型的準確性，這次進一步地在系統中，加入相對論的計算，用以觀察孤立子在相對論作用下的傳播及演化。我們可以觀察到不同參數的初始脈衝會影響到所生成的孤立子形狀，並藉由給予不均勻的背景環境，可以發現孤立子演化的準則。與期刊上發表的論文進行比較時，發現數值吻合，誤差約為1%。因此我們反向藉由論文中的運算式，解出一個孤立子，將其放入系統中，希望藉由這個方式更順利地了解孤立子在空間中的行為模式。未來，我們將利用這些結果來制定多維的電漿體數值模擬，其可以解釋現實宇宙中，蟹狀星雲能源運輸的問題。

It’s very important to control and monitor gases that are produced by industrial applications in different values and kinds because they can cause environmental pollution and health problems. Photonic Crystal Fiber (PCF), which is a different kind of optical fiber, is a new alternative for gas sensors due to their small sample volumes, low transmission losses and high flexibility properties. PCF’s are silica-glass fibers, made by periodic sequence of hollows along the fiber. By filling these hollows with optical liquids or gases very sensitive sensors can be made. In this project, we aimed to design a sensitive sensor by filling the hollows with proper gases and liquids in the solid core PCF. For these applications ethanol, methanol, toluene vapors and carbon dioxide was used. And to observe carbon dioxide’s effects ionic liquid (EMIMBF4), which carbon dioxide can dissolve in, was filled then the experiments were repeated. It was observed that the transmission of light in PCF changed depending on the refractive index of the gas that was filled. With this change, it was understood that there were another gas besides the usual containments of air. Our system could measure the absorbtion peak of toluen so it can be used as a toluen dedector and when ionic liquid filled the fiber, two steps that occur in the spectra of corbon dioxide so it can also be used as a carbon dioxide dedector. The system was customized as a carbon doxide sensor in a cost-efficient and portable way. Our system can be specialized and easiliy used with right light source, which is efficient to see the absorbtion peaks, and proper liquids to dedect intended gas. Making a carbon dioxide sensor by filling PCF with ionic liquid was never attempted before. Also the lack of carbon dioxide sensor studies supports the originality of our project. That’s why we think our project will contribute very importancies to the existing literature.