全國中小學科展

地球與環境科學

利用日光偏振訊息簡易計算觀測者所在經緯度之研究

研究利用日光偏振訊息找出太陽方位,發現ω(日光強度的極大值對稱軸旋轉角度)與太陽方位角As的關係為:As=-ω+φ,負號代表逆時針旋轉,φ為偏光膜初始角度。且驗證偏振度P和Z值之關係為P(θ)/Pmax=2Z-1,其中Z=1/(1+sin2((hs));任何時刻觀測由東向西的日光強度會呈雙峰變化,找出與峰值觀測方向夾90°的平面會通過太陽,進而求得太陽高度角hs。 採用三角定位法,以原地觀測不同時刻的太陽方位角,及太陽直射地球的經緯度,推算觀測者所在經緯度,若再輔以球面三角形法修正,可提高精確度。本計算模式在9時~15時的範圍內誤差約小於5°,比只能在正午時推算經緯度還來的便利。

水庫吸塵器—水庫水力旋流排淤之探討

為改善水庫淤積問題,提出清除泥砂淤積與水土資源回收之解決方案,本研究採旋風吸塵器概念製作結構簡單的水力旋流分離裝置,可在水庫供水時同時排淤,並運用虹吸引水方式抽取淤泥,以高度、管徑、圓桶長度作為影響旋流分離的主因,經實驗發現,改變此三項變因可影響流速,進而影響分離率,實驗中可有效分離99%河砂與97.5%白河水庫淤泥。 從模擬水庫排砂的實驗中,探討淤積粒徑的分布區與不同水力排淤工法的效益,依實驗結果得到水力旋流分離適用於水庫中上游粒徑大於黏土的淤積,水庫下游可搭配排淤隧道排出較難分離的黏土淤積,兩者搭配使用清淤將可不再受天候限制,並可蓄清排淤達到節能減碳的效果,延長水庫的壽命並降低原水濁度。

Chlorella vulgaris chlorophyll a fluorescence as a potential indicator for zinc and nickel detection

Heavy metals contaminate many bodies of water, posing a health risk to not only organisms that live and use the water in these areas, but also to the humans that live nearby. Chlorella vulgaris, a microalga, is one organism whose chlorophyll a fluorescence can indicate the presence of these substances, detecting any changes in concentrations using fluorescence microscopy and other fluorescence devices. The study explores the sensitivity of C. vulgaris to the heavy metal zinc where the algae was exposed to five concentrations of zinc: 0 ppm, 5 ppm, 10 ppm, 50 ppm, and 100 ppm. The fluorescence of the samples was observed with a fluorescence microscope on days 0, 4, 7, and 12, where the algal samples were adapted to the dark for 5 minutes, then exposed to light for 90 seconds. The values of the minimal and maximal fluorescence of the samples in the dark were noted. There is a significant difference in the values of the minimal fluorescence, maximal fluorescence, and maximum quantum yield, a value derived from the minimal and maximal fluorescence, at the highest concentration, 100 ppm, from the other treatments for the entirety of the experiment. The significantly low values at 100 ppm and the calculated EC50 of 75.70 ppm indicate that C. vulgaris is indeed a viable indicator for zinc detection at this and higher concentrations of zinc.

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。

臺灣極端寒流個案與東亞地區冬季氣候之關聯

本研究定義1967~2016年的極端寒流並將其分成1985前與1986後兩個時期,進行前後期寒流個案合成之綜觀環境場的比較,得知前後期確實有所不同,且以天為單位,後期寒流及非寒流差異較不明顯,推測需要更長時間尺度才能凸顯差異。再以臺北冬溫與世界冬季的溫度、風場做相關性分析,發現緯向風的蒙古地區,在前後期正相關性都相對明顯;經向風則是西伯利亞西部的負相關在前後期皆較明顯。因此,我們分別取蒙古緯向風及西伯利亞經向風以月為單位做不同季節延遲、同步及領先的迴歸分析,並發現與臺北冬溫相關性最高者,分別為蒙古冬季同步緯向風,及西伯利亞春季領先2經向風。最後為了驗證,再將此二風場1967~2016年的數據分為寒流、非寒流期間及全部數據進行比較,觀察同個月份在寒流及非寒流期間與平均值的差別,也探討這些差異與臺北冬溫三個月份間的差異有何異同,結果證實寒流及非寒流大多具有明顯不同。

全球平均海平面的年際變化(1993-2017),Mean Sea Level Variations on Inter-annual to Decadal Timescales, 1993-2017

本研究探討年際氣候震盪對全球平均海平面的影響,故將衛星測高儀數據剔除長期趨勢與季節波動後,與數個氣候指數進行互相關及同調性頻譜分析,其結果為:(i) 海平面與 ENSO,尤其是 Central-Pacific Types 在一年半以上的時間尺度,有高度相關,相關的原因可能與混合層溫度變化、陸地降雨海陸分布的變化有關。(ii) 海平面與 PDO、AMO 的相關性分別集中在 4 年以上與 2 年到 10 年,海水的熱含量變化可能是主因。AMO 相關性最高是在其比海平面早發生 8 個月的時間。 (iii) 雖然研究資料不包含北極海,但結果指出海平面與 AO 有弱相關,意味著北極海的年際溫鹽變化,對於全球海平面有遙相關的影響。(iv) 海平面與 AAO 似乎有弱相關,但是無法確定。最後本研究將上述五個指數以最小平方法擬合海平面年際變化,得到各指數的相對強度貢獻比例,有助於了解在未來全球暖化下的海平面變化。

Removal of Nutrients by Chlorella Vulgaris Microalgae in Bandar Abbas Municipal Wastewater

The entry of nutrients into the environment can cause the creation of eutrophication of aquatic ecosystems. One of the methods of removing nutrients from effluents is the use of algae. Algal purification is a new and inexpensive technology for this purpose. The present study investigated the rate of cell growth and nutrient removal of urban wastewater in Bandar Abbas in winter 2020 by the Chlorella vulgaris microalgae in the phycolab of Fisheries Research. Treatments with different dilutions (0%, 25%, 50% and 75%) were prepared; in addition, specific growth rate, cell density and removal efficiency of phosphate, nitrate, nitrite were examined during a 14 day period with initial constant density (1×10⁶ cells / ml ) of microalgae. The results indicated that 0% and 75% dilution had the highest and lowest cell densities (8.675×10⁶ and 56.633×10⁶), respectively; moreover, they had the specific growth rate (0.166 and 0.311). Furthermore, there was a significant difference between them (P≥ 0.05). The highest nitrate and nitrite removal efficiencies were -40.75 and -79.84 in effluent dilution of 50%; in addition, the lowest were 1.26 and -40.26 in dilution of 75% and 25% respectively. Phosphate had the highest removal efficiency at 0% dilution with a mean of -79.65 that showed a significant difference with the lowest at 25% dilution (P≥ 0.05). Therefore, high or low levels of nutrients can affect the removal efficiency and growth rate of microalgae.

雙眼牆颱風的內眼滾動

本研究初步分析颱風雷達回波圖發現,利奇馬、蘇力、柯羅莎、杜鵑4個雙眼牆的颱風,內眼牆有沿著外眼牆內側旋轉的現象,時間尺度約為3至14小時。接著比較颱風個案,選定杜鵑颱風作為主要觀察研究對象,以探討影響雙眼牆颱風內眼牆滾動週期的因素為研究目標,並以數值模式簡化問題。我做出兩種猜測,認為此一現象的成因,有可能是眼區的繞轉,或是內眼牆被眼區內的正渦度帶動旋轉。我先後設計了單、雙眼牆旋轉實驗,發現影響此二系統旋轉週期的主因不盡相同。其中,從雙眼牆實驗的結果可以發現,影響內眼牆滾動週期的參數,主要是眼區半徑以及眼區渦度,呼應了內眼牆受眼區內渦度帶動旋轉的猜測。最後,我在模擬杜鵑颱風的實驗中,做出相似的旋轉週期,證明內眼牆滾動的機制,主要以水平動力為主,也證明先前實驗的參數,即是影響旋轉週期的要素。

Ecological inks for markers

Markers have become essential in school and work life due to their great usefulness for teaching and homework. Despite the benefits they have brought, markers are the cause of great contamination from the ink manufacturing process to the excessive production of plastic. Ecological inks in markers and the innovative design of a refillable marker, allow to generate less pollution without having to stop using this product. From dyes created with coffee, fruits and vegetables that pass through different processes, natural inks arise that replace the use of polluting dyes. Likewise, implementing recycling plans in different institutions, markers that were no longer used were collected to be filled with ecological inks and used again. In addition, the excessive production of plastic is reduced by selling and refilling markers and ink kits.

高鐵行經嘉南地區之高鐵低頻震動波

當高鐵行經地層下陷明顯區域、或土壤液化中高潛勢的沖積層時,行車的車身震動會更劇烈嗎?本研究基於這樣的動機,經由測量高鐵沿線不同區段的震動訊號,了解各段的震動特徵。 本次研究使用微機電加速計(MEMS sensor)來量測高鐵行經左營至台北路線上車廂內之震動,並利用QCN Live軟體分析波形,分析行經各站間之頻率與振幅特徵,結果發現,行經台南到嘉義、嘉義至雲林、雲林至彰化三段路線的震動,在濾波0.5-4.0 Hz之平均振幅大於其他非地層下陷與土壤液化地段,同時我們也發現低頻振動的最大振幅在列車行經土壤液化區時有顯著的增加。