全國中小學科展

2021年

HYBRID COMPOSITE FROM X-RAY WASTE

This study considered the tensile and flexural characterization of new lighter and cheaper hybrid composite materials to replace the existing insert panel for the currently available bulletproof vest. The materials chosen included a natural fibre, i.e., kenaf fibre, chemically treated with sodium hydroxide solution, and, as a means of recycling, used x-ray films with a surface treatment. Using the traditional hand lay-up method, the materials were fabricated into seven layers of different configurations, which were then subjected to tensile and flexural tests. The findings showed that one of the configurations that consisted of both treated materials had a tensile strength of 396.9M Pa, which is quite strong, and a flexural modulus of 6.24G Pa, which makes it flexible enough to be made into wearable equipment. This configuration was then chosen to be the base design for the specimen subjected to impact test. The interfacial bond between the two distinct materials proved to be a major issue, even with the help of fibre treatment. Therefore, some improvements need to be made for the material to be comparable to existing materials performance-wise hence making this configuration suitable for ballistic application.

New Approach to Food Packaging: Antimicrobial and Edible Materials

In addition to adequate and balanced nutrition in the protection of human health, the reliability of consumed foods is also of great importance. When foods contact with the environment, they are undergoing many microbiological, physical and chemical changes such as moisture loss, aroma exchange, oxidation and contamination with microorganisms. So this changes reduce quality and shorten the shelf life. During cutting and processing of chicken meat, especially contamination on the surface causes deterioration of the meat starting from the surface and thus short shelf life. Though contamination of chicken meat surface is inevitable, growth of contaminant microorganisms can be inhibited and microorganisms can be killed. In recent years, increased risks of infection due to antibiotic-resistant microorganisms have forced the discovery of new and natural antibacterial materials. It is a new and advantageous approach to avoid environmental pollution caused by the use of food packaging and safety of food, prolongation of product shelf life by natural, edible, antibacterial biomolecules in packaging products. In the scope of the project, in order to produce an edible alginate gel containing the antimicrobial peptide nisin, which has an antibacterial property to prevent microbial growth on the surface of chicken meat, following steps was done;  Synthesis of calcium alginate and nisin immobilized calcium alginate beads  Optimization of immobilizing nisin in calcium alginate beads,  Characterization of nisin immobilized calcium alginate beads by ATR-FTIR Spectrum and SEM Analysis,  Determination of the antimicrobial activity of white meat product chicken which is coated by nisin immobilizing calcium alginate gel.

Sustainable G-Polymer From Industrial Waste

This study focuses on the pre-treatment of paper sludge ash (PSA) as a by-product of paper milling industry that contains high amount of calcium, yet low in silica. The presence of high calcium content in geopolymer system will accelerate the setting time of fresh geopolymer and may disrupt the development of its mechanical strength. Therefore, in this study, the refinement of PSA properties was conducted by treating raw PSA in hydrochloric acid solution with different molarities of 0.5 M, 1.0 M and 2.0 M. The pre-treatment process was mainly purposed to decrease the amount of calcium and other impurities through leaching mechanism. Based on the experimental results, 2.0 M hydrochloric acid solution (HCl) was determined as the optimum concentration due to its ability in removing higher amount of calcium from the ash, yet still able to increase the amount of silica. Compression test on the hardened properties of geopolymer specimen also showed the deceleration of fresh fly ash based geopolymer and produced a more workable fresh geopolymer.

探討粒線體如何參與調控細胞內鈣離子訊息傳遞

鈣池調控鈣離子內流(store-operated calcium entry, SOCE)是非興奮性細胞中最主要的鈣離子通道。當內質網缺乏鈣離子時,位在內質網上的STIM1(Stromal interaction molecule 1)便會改變構型與在細胞膜上的ORAI1(Calcium relaease-activated calcium channel protein1)接合,激活SOCE的路徑。近來的研究顯示,粒線體會影響SOCE的活性。已知平均有5%-20%的粒線體藉由連繫蛋白與內質網相連。又已知內職網在缺乏鈣離子時會移動至細胞膜附近,故我們認為粒線體有很大的機率藉由連繫蛋白與內質網一同移動至細胞膜並透過吸收鈣離子的機制來調控SOCE的活性。 在使細胞表現特定螢光蛋白的前提下,我們透過活體細胞攝影來觀察特定對象(粒線體、粒線體內鈣離子)的動態變化。 從實驗結果中我們發現:當SOCE被激活後,粒線體會移動至SOCE發生處且較靠近STIM1。又絕大部分移動至SOCE發生處的粒線體同時也會吸收鈣離子。 過去的研究已證實,當粒線體與內質網之間缺乏鈣離子時,SOCE的活性會降低,且當粒線體內膜的主要鈣離子通道MCU(Mitochondria calcium uniporter)缺乏時,亦會導致相同的結果。又從我們的實驗可知當SOCE被激活時,粒線體會移動至SOCE發生處並吸收鈣離子。綜合上述,我們可以推論以下機制,當細胞內的SOCE被激活時,粒線體會藉由連繫蛋白與內質網一同移動至SOCE發生處,同時以吸收鈣離子的方式來調控SOCE的活性以及細胞內的鈣離子濃度。

建構三種以上相異整數邊長的圓內接多邊形

前作「建構邊長為整數的圓內接多邊形」[2]中,我建構了多類兩種相異整數邊長的圓內接多邊形的一般式。本研究利用n倍角公式,建構三種以上相異整數邊長且外接圓半徑與所有對角線長均為整數的圓內接多邊形。 我依正整數的分割數將圓內接多邊形分類。除了正多邊形之外,6類圓內接五邊形、10類圓內接六邊形、14類圓內接七邊形。取畢氏三元數做變數變換,做出所有類型相異且有不同邊長的圓內接多邊形。另外在建構圓內接八邊形、九邊形與十邊形時,我考慮建構邊長相異且其中一邊為外接圓直徑的圓內接四邊形、圓內接五邊形與圓內接六邊形...等,將上述圖形做適當的伸縮與組合,即可以建構邊長皆為相異的整數的圓內接n邊形。研究過程也發現可用同一組一般式可建構不同的圓內接多邊形。最後推得各類非等邊長且外接圓半徑亦為整數的圓內接多邊形皆可尺規作圖。

The Waves Fish Controller

Our oceans, coasts, and estuaries are home to diverse living things. These organisms take many forms, from the tiniest single-celled plankton to the largest animal on Earth, the blue whale. Understanding the life cycles, habits, habitats, and inter-relationships of marine life contributes to our understanding of the planet as a whole. Human influence and reliance on these species, as well as changing environmental conditions, will determine the future health of these marine inhabitants Humans influence the whole environment even if they don’t notice , the growth of men and our increasing reproduction over the years results to an over consumption of nutritious products , which makes us exploit the wildlife more and more and in the same time take parts of its habitats for us to life in and throwing our non-needed materials in what’s left of the world. And that’s a big problem because the Eco-System was just fine before we started over exploiting it in a greedy and unreasonable manner, and since the ecosystem’s parts are related altogether in an ongoing circle , the absence or the destruction of one part of It may lead to the unbalance and even destruction of the whole organized system. And that’s why as humans, it is our first duty to take care of nature generally and both fauna and flora specifically, not because of a moral code of some kind; but to protect Humanity from ourselves, and to preserve the human kind from destruction and extinction. And that’s the main goal of our project, that’s to help us organize our fishing exploitative activities with how much can the environment handle from it.

LENS WITH VARIABLE OPTICAL CHARACTERISTICS

Research work on creating a lens, the optical power can be changed depending on human needs. Most people have visual impairments that need to be corrected with surgery or optical devices (glasses and contact lenses). The optical characteristics of the human eye vary depending on age, health, intensity of visual load. We propose to give people the opportunity to smoothly adjust the optical power of the spectacle lens by changing the transparent tubes between the two windows of transparent films. Experimental studies have shown the possibility of adjusting the optical power of the proposed line in a wide range. Existing devices and materials for changing the optical power of the line are analyzed. The design of a lens with variable optical characteristics is proposed, which is created from two window films, the space between which is filled with liquid. Publicly available materials for the outer shell of the lens and liquid for its filling. The effect of the amount of liquid to be filled on the optical power of the lens was experimentally determined. The formula for experimental finding of focal length of a lens is entered. Novelty is impossible because you can use the lens in another field. For example, in the future it is planned to perform an experiment with a lens system to create, for example, a telescope.

從遙測看水色與紫外線及溫度之關聯

本研究使用NASA Ozone Watch南極臭氧濃度、MODIS Aqua之全球海平面水色、NOAA Operational SST Anomaly之均溫異常,以及Australian Antarctic Data Center南極葉綠素濃度數據,探討三大洋海洋水色的逐年變化以及影響因素。我們認為受到環境變遷的影響,影響水色最主要的外在因素可能為紫外線及溫度。本研究利用image J軟體,估算臭氧洞逐年的範圍變化,並利用水色換算出的葉綠素濃度的變化趨勢,將上述數據製作成圖比較。 結果顯示:在紫外線的部分,葉綠素濃度會隨著紫外線入射量減少而提高。在深度的部分,南極同一時間點所測數據顯示,水表到400公尺深的範圍中,呈現深度越淺葉綠素濃度越高的趨勢。此外,海表溫度正異常(>1.5°C)之面積分布,證實海水表面溫度變高時,葉綠素濃度變高,南極數據也顯示相同特徵。我們認為,生物基於避險本能,在紫外線過量時,生物會傾向往海洋深層移動;在10℃~35℃間,溫度越高,葉綠素濃度越高,影響浮游植物在深度的分布。上述各項皆能影響水色。

Biodegradation of Post-Cured Photopolymeric Resin of Stereolithography 3D Printers Using Galleria mellonella Larva.

The present research has as main objective to degrade the post-cured photopolymer of the stereolithography 3D printer resin using Galleria mellonella larvae. It is necessary to consider that the use of materials from 3D printers tends to increase considerably and in approximately seven years about 10% of everything that will be produced in the world will come from this type of printing. Considering also that the increase in population growth and technological development are directly linked to the increase of solid waste on the planet, in particular to polymeric materials, there is a need to degrade and give an adequate end to waste, avoiding a notorious accumulation along the time. For this purpose, Galleria mellonella larvae will be used because of it's comprovated capacity to degrade polyethylene, to find out if it is capable of biodegrading the post-cured resin of the printer. To carry out the research, compositional tests were done in partnership with the SENAI Institute for Innovation in Polymer Engineering, located in São Leopoldo, Rio Grande do Sul, and the creation of the larvae and degradation of the photopolymer will be carried out in partnership with the University Federal University of Health Sciences of Porto Alegre (UFCSPA). The data analysis will be based on the crystallinity determination tests by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and attenuated total reflectance spectroscopy (ATR) that will also be applied in the larvae feces after contact with the polymer to assess for degradation. As a result of the compositional tests, the ATR showed predominantly characteristic absorptions of acrylic resin; in the TGA test, the loss of mass described in the test is related to the loss of mass of organic material, mainly polymer. Finally, in the DSC test a thermal event was observed in the heating of the sample, with peaks at 125 ° C (Tpm), characteristic of fusion, and a thermal event in the cooling of the sample, in 112 ° C (Tpc), characteristic of crystallization. Based on the analysis of the results obtained, it is possible to infer that most of the composition of the photopolymer is acrylic resin, widely used in stereolithography 3D printers. The research has the future objective of isolating the substance into the larvae responsible for degradation so that it can be degraded on industrial scales. The research started in March 2020 and is still under development due to the COVID-19 pandemic, which compromised the planned tests.

探討造孔劑粒徑與添加量對天然水膠軟骨支架之孔洞型態影響

軟骨修復目前仍是臨床治療上的挑戰,組織工程扮演著可行性的解決方案。軟骨修復中,軟骨支架是關鍵的要素。本研究使用天然高分子水膠透過溶劑鑄造鹽洗法製備軟骨支架,去探討造孔劑粒徑大小(大粒徑:170;小粒徑:250)與添加量(低量:2克;高量4克)是否會影響製成軟骨支架的物化性質,以及會影響前驅骨母細胞分化的能力。透過觀察所製成的四種軟骨支架顯微結構,分別測試其吸水量、降解性、抗壓強度與交聯度,並測試其生物相容性與促進前驅骨母細胞增生及分化之能力。結果發現,造孔劑粒徑大且高添加量的軟骨支架 (170-4組別),雖抗壓強度僅 0.0177 MPa,每克支架吸水量達 14.72 mL ,浸泡於試劑 30 天後,支架不會明顯降解,且不具細胞毒性,促進前驅骨母細胞增生與分化的能力最佳,因此可作為適用於軟骨缺損修復之組織工程支架,提高軟骨修復之成效。