培地茅根系碎形維度及抗拉力
本研究首先確認培地茅根系具有碎形之基本特性,再進一步以方格覆蓋法計算之碎形維度來分析培地茅根系在不同時間及環境因素下的生長。主要探討碎形維度與抓地力之關係,並設計以實際根系模型來加以模擬,並發展出一可描述抓地力與碎形維度及深度關係的方程式。我們的結論為:(1) 經由方格覆蓋法之計算,培地茅此種植物,不管是整個根系或單枝根,均具有碎形基本特性,適合進一步實驗研究。(2) 碎形維度會隨著培地茅生長時間增長而增加,並且在自然光照及30℃左右會有較大值,而種植於土壤中根系發展較廣,其碎形維度比種植於沙耕中來的高。(3) 實驗結果顯示,抓地力受碎形維度及根系深度兩因素影響,而培地茅根系對土壤有較強的抓地力,推測是因為兩者根系皆又深又長,土中培地茅根碎形維度較大,接觸面積較廣,而又進一步以矽膠模型做實驗驗證。(4) 矽膠模型之目的在於減少難控制之自然變因,實驗之前,測量了根系模型與洋菜凍之基本性質,實驗結果顯示抓地力與碎形維度及根系深度皆呈正向關係,可用數學方程式加以描述。This project is mainly a research into the fractal dimension of the vetiver root system. First, we confirm the vetiver root system has the basic fractal structure by checking its self-similarity, then using box-counting method to calculate fractal dimension. We begin with a fundamental investigation into the relation between different time and environmental factors and fractal dimension. Then we move to our main point: the relation between fractal dimension and its pull-out resistance. In the next step, we make a fundamental silicon model, simulating the vetiver root system, to continue our experiments. In the end, we develop a formula that can describe the relation between its pull-out resistance, roots depth and fractal dimension. Here are our conclusions: (1) After using box-counting method to calculate fractal dimension, we discover that not only the whole vetiver root system but also a single vetiver root has the basic fractal structure. (2) Fractal dimension increases when time goes on. Also the value of fractal dimension is larger in natural sunlight and the temperature at about 30℃.The vetiver root system grows more widely in soil than those in sand. That’s why it has larger fractal dimension. (3) Data shows that its pull-out resistance is influenced by both fractal dimension and the depth of the roots. The vetiver roots, in the meantime, show greater pull-out resistance than some other plants. Thus we draw the assumption that the vetiver root system grows deep and wide, and in natural soil its fractural dimension is greater and reaches greater area. Therefore, a silicon model is constructed to further confirm the findings of the experiment.(4) The design of the silicon model is to reduce the uncontrollable variables in nature. Before starting the experiment, we measured some basic characteristics of the silicon model, including density and angle of repose. Furthermore, the experiment demonstrates that pull-out resistance and fractural dimension have a commensurate mutual relation: the stronger the pull-out resistance, the wider the fractural dimension and the deeper the root system. Thus we derive a math formula to describe this relation.
立體尺規作圖-PES 作球
In this study, we mainly explore the geometric construction in 3D. By conducting some problems about constructing circles, we define the PLC construction in 2D as constructing a circle, either passing through a given point (P), tangent to a given line (L) or tangent to a given circle (C). Besides, we aim to discuss the properties of the PLC construction and the relations between each other. We discover if we find a plane satisfying certain conditions in space, the properties in the PLC construction can apply to such a plane. Furthermore, we extend the properties in PLC to the PES construction in 3D, defined as constructing a sphere, either passing through a given point (P), tangent to a given plane (E) or tangent to a given sphere (S). Also we discuss the relations among them.這個研究主要在探討3D 的尺規實作。藉由歸納某些有關作圓的題目,我們定義2D 中的PLC作圖─作圓,過已知點(P)、切已知線(L)、切已知圓(C)。並探討PLC 作圖的性質及彼此的關聯性。而我們發現:在空間中只要找到滿足特定條件的平面,則2D 幾何作圖性質在該平面仍能沿用。此外,運用PLC 作圖性質,我們進一步推廣到空間中的PES 作圖─作球,過已知點(P)、切已知面(E)、切已知球(S),並探討各個類型間的關聯性。
Prototype for the production of Biofertilizer
The Latin American and Caribbean regions have one of the biggest cultivable areas in the world, calculated at around 576 million hectares. Nevertheless, 16% of this land its affected by a kind of soil degradation. Previous studies have shown that the vesicular- arbuscular mycorrhizae (VAM) can fix phosphorus and other elements to plants, is an important micronutrients transporter, increases the water potential of plants, can bioremediate the lands affected and prevents lixivation. These effects are very convenient and can replace the chemical fertilizers which produce collateral damage to the environment. For the reasons mentioned above, this prototype for the production of vesiculararbuscular mycorrhizae, denominated as a biofertilizer, is presented. The prototype consists of an aeroponic system which disperses, in aerial form, nutrients to the host/trap plant roots where the fungus produces its mycelium web. The fungus propagation consists of an artificial union of isolated and identified spores of the mycobiont ,which we want to propagate, with the trap plant roots. The specimen identification consisted in a staining and clarification method (Phillips- Hayman), and a taxonomical identification. In order to prove the (VAM) benefits, two experiments using Sorghum spp. were carried out. One consisted of a comparison between the plants with VAM and a control without VAM. The second one consisted of a chemical comparison between control/fertilizer/ VAM plants. These two experiments were subjected to a water stress test for 10 days. The prototype achieved a production of roots mycorrhizae between 50-65% of colonization. The taxonomic identification corroborated that the mycobionts propagated and the controls were the same species. Experiment One demonstrated that the mycorrhizae treatment has more height, stem diameter, fresh/dry weight than the control which doesn't have VAM. We also conducted the Student’s t Test to check the previously mentioned hypothesis. In Experiment Two, the control and fertilizer treatments had a similar percentage of Nitrogen and Potassium, and the mycorrhizae treatment significantly increased these two elements; nevertheless, the fertilizer and mycorrhizae treatment obtained a similar percentage of Phosphorous. The water stress test was for 10 days - one month after planting. The results were: the fertilizer and mycorrhizae treatment had the same resistance to the stress, the mycorrhizae recovered faster from the stress and the control specimens presented a lower shrivel percentage than the other plants. One of the principal gains which this prototype has is that the trap plant doesn't die after collection, and the plant only needs to be inoculated once in the plant’s life because we only prune the roots. In nature 90% of plant species present some type of mycorrhizae association, hence the feasibility of this prototype for introduction, use and application of the fungus as a biofertilizer. 1 Centro de Bachillerato Tecnologico Industrial y de servicios N°24 2 Instituto Tecnologico de Ciudad Victoria
漩渦也有形
流體旋轉時,外圍及底部流體,因槽壁及槽底摩擦力的影響,流速較慢,相對的壓力也較大,導致外圍的水流會轉入中心。發現本實驗的渦流為強迫與自由漩渦組成。實驗中,探討f(轉動器的頻率)、H(總水深)、y(?入深度)、R(轉盤半徑)四者與角形數間的關係。若y、R 愈大、H 越小,隨著f 的增大,可觀察到的形狀邊數越多;反之,若y、R 愈小、H 越大,則f 愈高,所形成的圖形半徑愈大,易超過轉盤,不易觀察。依白努利方程式,外層水流的流速較慢,而內層水流的流速較快,故外層壓力大而內層壓力小,水會由外往內流,而此渦動流於轉動液面產生的剪力,可能為產生N 邊形漩渦的主要原因之一。流體旋轉系統中,因轉動而產生流體離心力與內外層壓力差交互作用下,於某特定相關的因素條件下,形成特定角形數漩渦,是本實驗的重要發現。When fluids are in rotation, fictitious force given by the container brings about the relative decrease of speed of the bottom and outer layer of water, which causes its pressure to increase, and water to spin inward, resulting in a vortex motion with N-corner polygons formed at the surface of the rotating plate. During this experiment, we discover that the vortices consisted of free and forced vortex and the polygons vary as control parameters f(rotation frequency), H(height of fluid), y(depth of the plate), and R(radius of the plate) change. The larger y and R are,the smaller H is, the more corners show up as f increases. On the contrary, the smaller y and R are,the larger H is, few polygons are identified since the rotating radius of polygons are larger than the plate. According to Bernoulli’s principle, smaller velocity of the outer-layer water causes water pressure to increase and water to spin inward. During this process, shear force is developed at the surface of the rotating fluid, which we believe is the main cause of N-corner polygons. In a rotating system, the interaction of centrifugal force and differential pressure causing a certain Ncorner polygon to be formed under different controlled parameters is our main discovery.
全民攻笛
本實驗主要是研究閉管駐波的發聲原理。何謂「閉管駐波」?就是一個管子在相同長度下,用不同的力道吹,會有不同音高的聲音產生,這些音被稱為「諧音」。原管長所能發出的最低頻率稱作「第一諧音」,第二低的聲音稱作「第三諧音」,依此類推。在簫的演奏上,只要按住同樣的孔,用較大的力量吹,也同樣會發出較高的音;同樣地,在曲笛的演奏技巧上,有平吹、急吹等分別。為什麼吹越用力,音就越高呢?如果現在拿一個大吸管吹(要裝活塞),你會發現,只有在特定的位置(角度)下,才能吹出聲音。那麼,角度對於聲音也有影囉?這些現象的幕後黑手,就是在管口產生的「渦流」,渦流頻率也會隨著風速而增加;而且,渦流的頻率在特定風速下,會有特定的範圍。經由實驗可以大略歸納出,影響閉管駐波的三個主要變因,分別是「風速」、「風吹角度」、及「吹口至管口的距離」。吹得越急,風速就越快,渦流頻率越高,越易使諧音躍遷;吹的角度越小,越易產生渦流,亦易引發聲音;吹的距離越小,渦流越不?定,越易產生其他的擾動。以上就是本實驗的概略。This project is aimed to fine out how the closed tube can produce a sound. We know what harmonics are. When we hold a big straw and blow with increasing strength (the bottom should be in water), it will generate a higher sound. The high sound is called “harmonic”. The lowest sound it can make is “the first harmonic”, the second lowest sound is “the third harmonic”, and so forth. Likewise, when we press the same key on vertical bamboo flute with increasing strength, it’ll also produce a higher sound. But why do we use the strong air stream to blow the tube to cause the tone to transfer? Now let’s blow a straw flute. You will find that you need to blow in the particular position, and then the sound will be produced. So, is there any relationship between the blowing angle and the frequency? Actually, all these sound are produced by “vortex in the mouthpiece.” The frequency of vortex will increase with the wind speed. Moreover, the frequency of vortex has a range. In sum, the higher the wind speed is , the higher the frequency of the vortex is , and leads to the higher frequency of the sound. The smaller the blowing angle is, the easier the vortex will be produced; the easier the frequency will be made. The smaller the distance between the blowing angle and the frequency is, the more unstable the frequency will be. The above is the most important research in this project.
萬用虎鉗夾具
機械加工過程中往往遇到形狀複雜工件,無法用一般虎鉗夾持進行加工。若需加工複雜工件時,需使用V 形槽、壓枕……等等夾具加以輔助,但有些夾具根本無法夾持。若用特殊夾具需拆除原有之虎鉗,而且還必須校正,工作繁雜又浪費很多時間。 本設計之優點為不需更換虎鉗,直接放在虎鉗鉗口即可夾持不規則的物體,利用正向力的作用夾持而不打滑,輕易達到夾持時之穩定和足夠之夾持力,以達迅速、不需使用特殊夾具、不需再校正、可當平行塊之多功能夾具,使複雜形狀之工件加工簡單化、迅速化之設計。;When handling workpieces in complicated and irregular shape in the mechanical process, users are unable to make it with ordinary vises. V-block and clamping block might help, while some others do not work at all. In such cases, the user has to tear the vise apart and then do some correction, which is complicated and time-wasting. The strength of this design is that there is no need to replace the vise. The user just puts this device on the vise clamp to clamp the irregular object. The vertical clamping force makes the piece at work stable and allows no slipping. With this device, no special fixture or further correction is needed. It can also be used for a parallel block if necessary. In other words, as a fixture of multiple functions, the device makes the processing work simpler and more efficient than ever.
磁剎車系統探討
本研究探討運用磁場來達到非接觸煞車的功能,本實驗採用兩種方式來探討磁煞車力,分別為馬達有外加電流及沒有外加電流的情況。首先本實驗提供一穩定的電源使鋁盤轉動,觀察加上磁場及把電源切掉後鋁盤轉速的變化。實驗發現,當馬達沒有外加電流時,磁煞車力與轉速及磁場平方皆成正比;馬達有外加電流時,電流差會與轉速平方差成正比。探討磁煞車力與厚度及介質的關係,實驗結果發現,渦電流常數與厚度成正相關,且當兩片鋁片中夾有介質時,渦電流常數較小。 This experiment is based on the magnetic brake’s practical uses and braking forces. We want to calculate the braking force, and also examine the factors that cause the braking force to differ.We attached a metal disk to a motor to make the disk rotate, then we control the distance between the magnet and the metal disk, therefore measuring the relativity of the distance and the rotational speed. We discovered that when the metal disk received a large quantity of the magnetic field (close distance), the breaking force and the rotational speed increased. On the other hand, when the metal disk received a small amount of the magnetic field (far distance), the breaking force and the rotational speed decreased. The magnetic braking force will convert into kinetic energy, thus, by using this connection and also by increasing the electric current to measure the resistance, we calculated the magnitude of the magnetic braking force. Hence we perceived an inverse ratio between distance and the braking force, that is to say, the closer the distance, the stronger the magnetic braking force; the further the distance, the weaker the magnetic braking force.
Effects of Macromolecular Crowding on Model in vitro Antigen-Antibody Reactions
Many biological processes in the human body take place in intracellular environments under crowded conditions. This means that such cellular activities occur in the presence of inert macromolecules. These macromolecules are thought to have large effects on reaction rates and equilibria. However, under conventional conditions, these same processes are studied in vitro under uncrowded conditions in dilute buffers and therefore not reflective of physiological conditions. Hence, this project aims to study the effect of macromolecular crowding on antigen-antibody reactions in an attempt to mimic intracellular environments. It also aims to highlight the importance of introducing crowders as a factor of study in conventional in vitro experiments involving cellular reactions. The model reaction investigated involves human collagen type 1 on skin samples and specific antibodies against these antigens. Inert macromolecules of defined hydrodynamic radius and charge were added into the reaction media while quantitative tests are conducted to determine the effect of crowding on the rate and extent of reaction. The macromolecular crowders used were Dextran Sulphate, Ficol170, Ficol1400 and Polyvinylpyrrolidone360. Results were than analysed with the Metamorph 7 imaging system to determine signal strength under crowded and non-crowded conditions. At high primary antibody dilutions, skin samples incubated with a primary antibody solution crowded with a combination of inert macromolecules showed improve signal strength. This could be because crowding tends to shift reaction equilibria such as to minimise the amount of excluded volume, leading to association of the antigen and its specific antibody. This is known as the excluded volume effect. In addition, crowding the primary antibody solution helped increase the rate of reaction. The results also suggest that the addition of crowders may reduce the amount of antibodies needed per sample and decrease the necessary incubation time. Therefore, antigen-antibody reactions can be done more cost-effectively, However, the presence of charged macromolecules such as Dextran Sulphate has an inhibitory effect. Further work is also needed to establish whether macromolecular crowding enhances specificity and thereby reduce autoflourescence of the skin sample.