漂浮的油滴--CMC 的測定
Surfactants have a great effect on decreasing the surface tension in aqueous solution and thus they are important components in detergents. The present study aims to explore the cleaning mechanisms of the substances for greasy subjects such as bowls and clothes. The roles of various surfactants that have on the changes in the surface tension of aqueous solution in the presence and absence of additives such as tea and salt have been carefully studied by using a lab-made equipment. We carefully observed the changes in the oil droplets after pushing oil in a syringe to the aqueous\r solution containing surfactants and additives. With decreasing the surface tension of the aqueous solution, the size of the droplet becomes smaller. By using this simple lab-made equipment, we are able to determine the critical micelle concentration (CMC) of sodium dodecyl sulfate (SDS), with a result of 0.0079 M at 20 ℃. The result is in a good agreement with the literature (0.0077M). With decreasing temperature and adding salts such as sodium sulfate, the decreases in the surface tension have been confirmed by our simple experiments. This simple equipment also allows study of the effects of impure additives such as salt, tea, vinegar that have on the changes in the surface tension of aqueous solution containing commercial detergents. We have found that most of the additives have a great effect on reducing the surface tension of the aqueous solution. The present study results suggest that the simple experimental set-up is practical for measuring the CMC of surfactants and for exploring the effects of additives on changes in the cleaning ability of commercial detergents.界面活劑性可有效降低水溶液的表面張力,因此,他們是清潔劑的重要成份。該實驗主\r 要在探討各種物質的清潔機制。利用自製的實驗裝置,針對各種不同的界面活性劑在添加了鹽類或茶水後界面張力的改變量,作詳盡的探討。我們將含有不同濃度界面活性劑以及添加物的水溶液裝入容器中,在推擠針筒使其的油通過針頭並進入該溶液後,我們仔細的觀察紀錄油滴大小的改變。結果顯示界面張力的降低會使得油滴變小。藉這個自製的裝置,在20℃下,本實驗所測得的陰離子型界面活性劑-十二烷基硫酸鈉之臨界微胞濃度0.0079M。結果幾乎與過去的文獻0.0077M 值符合。該實驗同時也證實了降低溫度,添加了鹽類後,可有效的降低界面張力。此外,此實驗裝置也可以用來測量市面上販售的清潔劑在添加了不純的物質後,其界面張力的改變量。我們發現大多數的添加物都能有效降低界面張力。目前的實驗結果顯示,這項實驗裝置在測定臨界微胞上有很高的實用性,同時也可以探討不同的添加物對市面上販售的清潔劑之洗淨力的影響。
死亡巧克力—切切割割好計謀
三角形的邊上取任意多個點,我們可以把這塊大三角形沿著切割線切割成較小塊的三角形,但切割線必須是點(或頂點)和點的連線,而且必須切割三角形,同時可以切任意大小的三角形,如圖(1)與圖(2)。但不可以一開始就取走整個三角形。定義拿到最後一塊三角形的人獲勝,而在多邊型中的玩法與在三角形中相同。 我們分A、B、C三種規則來討論,其中A規則即是上面提到的玩法,B規則大部分的玩法和A規則都相同,唯一不同的地方在於:A規則中,只要有一方取到剩下的圖形為三角形,另一方就可以直接取走剩下的三角形,而B規則規定即使剩下的圖形已經是三角形,也必須取到剩下的圖形邊上都沒有分點為止。C規則是限制玩家一次所能取的三角形數來進行遊戲。 我們完成了A、B、C規則中三角形與多邊形的必勝策略,並找出必勝策略之間的關聯。 ;Given any numbers of points on the sides of a triangle, the players can cut this triangle into pieces. Each cutting line has to be one, linked between two points given from two different sides. And the player can’t have to cut smaller triangles out of the original triangle. The out-cut triangles can be chosen randomly without any restriction in size, just like what’s shown in picture(1)and(2). Meanwhile the first player can’t cut the original triangle exactly all out in the very beginning process. We define the player as the winner, who gets the last triangle. And the above way we play can be applies to any multi-side shapes. We discussed the question respectively in three rules, A, B, and C. Rule A is what we mention above. Rule B is generally the same as rule A, except for the only difference:The rule A , if there is any triangle left , the next player can get it directly, but while in rule B, the every next player has to cut out smaller triangles until no point is left on sides. Rule C proceeds on conditions that there is a limitation to a certain number of triangles cut out at a time. We has finished the winning tactic respectively in rule A, B, and C in the games with a triangle and multi-side shapes. Furthermore, we find the connection between the winning tactives.
Self Assembly Mechanism of Water Droplets
這是一系列關於水蒸氣冷凝為極細微水珠的實驗。其中可以歸納為三大部分,第一部分是基礎實驗,將水蒸氣導引至親水性介面上,觀察冷凝水珠的結構。雖然看似簡單平常,但是卻發現:不同溫度的水蒸氣,其冷凝最初始的細微珠粒,尺寸相同;爾後溫度高者,堆疊速率較大,以至於最後同時呈現的水珠大小不一,尺寸不同!
第二部分,是針對冷凝水珠自我組裝機制的探討。實驗是將水蒸氣導引至密度小於1的高分子溶液上,並藉由揮發性溶劑快速揮發,將水珠粒「分層保留」以便更深入了解「解構」後的水珠群聚機制。在這組實驗中得到兩張有趣的圖片:
在討論時,我是從對流機制切入,嘗試解構上面兩張圖。
第三部分的實驗,是將水蒸氣導引到磁場及靜電場上,觀察冷凝的機構。這部分呈現出來的結果,推翻了一般「水分子為電中性應該在電場與磁場中不受影響?」刻板觀念,實驗呈現水分子:不但在電磁場上不易長大同時也有固定的散佈模式(assembly pattern)。同時也觀察到:水分子在正電場形成的凝結水珠較為均勻,在負電場則表現出較大親水性特質。這部分的實驗對日後研究細胞膜上水分子通道應有助益。
I have tried to ask a famous math professor if he can create a formula describing the ordered array of water droplets. “Then, I should study Physics first!” He said. Condensation is the thing we live with, being found everywhere, passing without notice. But we never know when it dose start? By coalescence, water droplets grow bigger, but are not round again. We used the polymer film as template and designed the solution lighter than water, so the minute droplets will sink to the bottom and layer by layer. After seconds we may have multilayers of ordered array. This experiment presented here is actually the diary of the growth of water droplets through condensation, upon volatile fluid, magnetic field and electric field. Through convection, it discusses the self assembly mechanism of water droplets and peep into the uniformity of the size of water droplets. In this experiment, convection and magneto-electric force did play important roles in the self assembly mechanism of water droplets. The topic is mostly concerned as we are surrounded by magneto-electric waves in today’s world. This is the first step in discovering the homogeneous state of water droplets, providing insights into the self assembly mechanism of water droplets with nano sizes.
蜘蛛數
We understood the definition and meaning of spider number by reading〝Wonders of Numbers〞. It interested us so much. So, we took further step to study the situation of extreme value when the gap sometimes lie on the line and sometimes on the circle or even on both. That is to say, we explored the relation between spider number and the gap when the spider number is maximum or minimum. New research for the application of spider number involves several directions. First, we design a new game called〝Stepping Land Mine〞with the rule of spider number. Give you a net with several hidden gaps, trying to find the right positions of gaps. Second is the further result for a different type of net about regular n-polygon. Third is a tactic for a net with destroying of the strategy points. In this situation, the gaps amount on the circle and on the line are fixed. At the same time, consider the situation of circles and lines designing the tactic of placing the gaps to attain the maximum of the destructive effect. 在本文中我們定義一個蜘蛛網上的蜘蛛數,若在蜘蛛網中加入缺口後,會影響蜘蛛數的大小。我們探討蜘蛛網上的缺口,該如何分配才能夠得到蜘蛛數的極值(最大值及最小值)。先觀察一直線和圓上缺口如何放置蜘蛛數有極值,再探討許多條直線及圓上的情況,進而推展至許多同心圓及通過圓心的許多條放射線的缺口,該如何放置,蜘蛛數才會有極值發生。
二次函數上正三角形建構之研究及探討
在拋物線上置掛正三角形看似簡單,其實不然。本篇文章研究在二次函數的各種不同情況下,可做正三角形的分佈以及其個數。
1. 在一條拋物線上時,最多只能作正三角形。
4. 在三條對稱軸相等的拋物線和共頂點開口大小不同之拋物線上,本篇文章證明一定能找出正三角形落在它們之上。但由於最多有四個分界點,要解四次方乘組過於繁複,於是本篇文章對分界點作了一些估計,找出了分界點的極限值。
5. 本篇文章證明了對於給定的正n 邊形,存在一1 元n-1 次方程式可以通過它所有頂點。
Building a regular triangle on a parabolic curve looks easy . In fact , it doesn’t . This Article researches regular triangles distributions and its numbers in different conditions.
1. On one parabolic curve can only build regular triangles , squares and other regular polygons can’t be built.
4. For three parabolic curves which has same symmetrical axis or three concurrent parabolic curves, we prove that it can build at least one regular triangle on them .But because it can have at most 4 boundary points, to solve quartic equation is to complicated. So we do some estimation of boundary points, and find out some limits.
5. This Article prove that for given regular polygons , there exists a one dimension n-1 orders equation can pass all its apexes.
奇妙的三維世界
本實作以光學全像術為基礎,拍攝出三維立體的影像。內容主要為分別製作「穿透式」全像片、「反射式」全像片及「彩虹」全像片等三部份。其中,在反射式全像片中,嘗試以不同數量的光束來拍攝。發現以單光束法拍攝出的全像片比較容易成功,但重建影像的視角與效果都不如雙光束拍攝法來的好。在拍攝彩虹全像片的過程中我們令狹縫為變因,做有加狹縫與未加狹縫的實驗,實驗發現效果不同。並以改變狹縫的角度、方位,來觀察底片的變化。最後,觀察出豐富多樣的彩虹變化型態。全像片可重建拍攝的物光與參考光,並顯現拍攝物的三維狀態。可應用於信用卡、紙鈔防偽,廠商標籤,附加商品(如鑰匙圈、貼紙),廣告看板等,用途廣泛。 The purpose of this project is to construct the 3-dimensional images utilized optical holography. The holograms we made can be categorized into three main types: transmission, reflection and rainbow. In reflection hologram, we have tried to construct the hologram by the use of different number of light beams. It could be found that the reconstructed image of the hologram formed by a single beam is better than those of the hologram formed by two beams. However, the field of view and image quality of the two-beam hologram was better than those of single-beam hologram. In rainbow hologram, we varied the orientation and position of slit to investigate the quality of the reconstructed images. The reconstructed images displayed rainbow image diversity. In application, the holograms can display three-dimensional images by reconstructing the hologram. In addition, the holograms are in widespread applied in security applications of credit card、banknotes、labels、stickers etc.
A study to find out suitable colour to control pests of chilli plants using a colour trap
Chilli (Capsicum annuum L.) is one of the most important condiment crops in Sri Lanka. The main constrain in chilli cultivation is the Leaf Curl Complex (LCC) which reduces the quality of the pods as well as the yield. Many researches have been proven that the problem can be controlled by Integrated Pest Management (IPM) practices. Colour sticky trap is one of the mechanical methods in the IPM package which reduces the pest population successfully. Mainly three colours, namely blue, yellow and white have been identified as suitable colours for traps all over the world. This study was thus, conducted to find out the most effective colour for sticky traps to control chilli leaf curl complex in the Intermediate Zone of Sri Lanka. Traps were prepared from wooden plates of 30 x 25cm in size and the colours were applied in both sides of the plate. Both colourless and odorless vaseline was used as the sticky substance. These blue, yellow and white sticky wooden plates (traps) were fixed in 1m height from the ground level and they were used as the treatments. Six pots with 2 plants each of the variety ‘KA-2’ were used in a treatment and three replicates were sited for the experiment. All the agronomic practices were equally done for all the treatments. Number of trapped pests associated with the LCC was counted in 4, 6, 9 and 12 weeks after transplanting. The number of leaves affected by the pests in a canopy was counted in 7, 10 and 12 weeks after transplanting. The number of damaged green pods and the pod weight were taken at harvesting. The mean values of the number of pests trapped in white, yellow and blue colour traps were 162, 160 and 38 respectively. The percentages of damaged leaves in a canopy at 7, 10 and 12 weeks after transplanting in the blue trap were 89.07, 98.00 and 100.00 respectively. Those values in the white trap were 87.37, 98.90 and 93.29 and in the yellow trap were 69.03, 87.26 and 82.26. Percentages of damaged green pod weight in the blue, yellow and white treatments were 66.63, 47.06 and 45.65 respectively. These results suggest that yellow and white colours are more effective in sticky traps in pest controlling to control chilli leaf curl complex in the Intermediate Zone of Sri Lanka. Further studies are required to confirm the results.
奈米防蝕專家-微乳液法製備聚苯胺奈米粒子及其在防蝕應用研究
導電高分子在各面之應用非常廣泛,其中聚苯胺因價格便宜,製作簡便,使\r 其應用潛力更為突出。聚苯胺在鐵系及非鐵系金屬之防蝕能力已被證實,但由於\r 聚苯胺與金屬之附著力不良使其應用受到限制。奈米粒子所具有的表面效應、小\r 尺寸效應及宏觀量子隧道效應,使得奈米微粒材料之應用蓬勃發展。但在高分子\r 奈米微粒之製備仍屬有限。本文以微乳液法製備聚苯胺奈米粒子,以提高聚苯胺\r 與金屬間之附著力,使其防蝕能力充分發揮。國外雖已有廠家製作聚苯胺防蝕塗\r 料,但屬於商業機密無從得知其製備方法。本文所研發的微乳液法則是國內首\r 創!\r The development and application of the conducting polymer polyaniline is\r getting prosperous and popular. The capability of polyaniline in corrosion protection\r has been proved. But due to the adhesion of polyaniline on the metal is poor, the\r applications are restricted. By the way, the nanoparticles have the special effects such\r as the surface effect, the small size effect and the macro-quantum channeling effect\r make its applications are prosperous.\r In this paper, the authors utilized the microemulsion method to produce the\r polyaniline, to modify the adhesion of polyaniline on the metal in order to improve\r the effect of the corrosion protection of polyaniline in ferrous metal. The experimental\r results show that the nano-polyaniline has good adhesion on metal. The metal coated\r a layer of nano-polyaniline has the great ability of anticorrosion under different\r corrosion situations after weeks. The nano-polyaniline produced by the\r microemulsion method add the recipes invented by the authors has great potential to\r use in scale-up production in industry.