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地球與環境科學

多尺度熵用於地震後結構物之診察

台灣位於太平洋地震帶,80%強震發生於此處,且台灣老舊建築為數甚多,因此震後結構物之健康診斷相當重要。 本研究為解決目視監測之侷限與實驗模態分析面臨邊界與縮尺效應等問題,基於操作模態分析,發展一套快速、方便與準確之結構物健康診斷系統。 使用地震儀量測結構物之速度訊號,透過區域基線修正與極端值修剪等訊號前處理,再利用Lo et al (2015)提出之Multiscale Symbolic Entropy(MSSE)計算不同尺度之熵值,以建立結構物於健康狀態下之模型,地震發生後以相同之方式量測、分析多尺度熵趨勢,並比對地震前後之模型是否改變,藉以判斷結構物是否受損。 經過十九次於兩座橋、五個測站之測量,再經過數據前處理後,利用MSSE計算多尺度下之熵,而多尺度熵之趨勢有高度之一致性,證明此方法適合用於結構物健康診斷。 應用層面來說,此方法不需耗費長時間來完成,只需要幾次之測量來確定其數據之一致性,並於地震後再進行另外幾次的測量,此方法即可判斷該結構物是否受到地震之影響。

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.

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.

颱風在短期與長期內影響海洋表層葉綠素a濃度改變之探討

本研究主要探討颱風強度對於海洋表層葉綠素a的濃度影響的程度。 颱風資料由Joint Typhoon Warning Center資料庫中選取2008~2012年之西北太平洋颱風,共104個颱風。每天中相隔12小時取兩組資料,包含颱風經緯度、近中心最大風速與氣壓;葉綠素a濃度資料則取自NASA Ocean Color資料庫,對應颱風路徑中每天兩個取樣時間,找出以颱風為中心,長寬各150km範圍內的葉綠素a濃度,並利用Matlab程式輔助處理大量數據。 為清楚了解颱風對海表面葉綠素a濃度的影響,研究中將影響時間分為短期及長期兩組分別進行分析。所謂「短期」是指颱風經過前、後一天內,而「長期」則是颱風經過的前一周到後兩周內的時間。 分析結果顯示颱風過後一天海表面葉綠素a濃度平均增加近50%,且颱風近中心最大風速與中心氣壓在短期對於葉綠素a濃度分別呈現正相關與負相關;而長期來看,無論颱風近中心最大風速或是中心氣壓和葉綠素a濃度的關係較不明顯,但是颱風過後10天內,海表面葉綠素a濃度明顯高於颱風來臨前。

STUDY OF ATMOSPHERIC AIR POLLUTION OF POLTAVA REGION

Ukraine as a whole, as well as Poltava Region in particular, have a problem with the state of atmospheric air pollution, because the vast majority of motor vehicles and industrial, energy, and mining enterprises are not equipped with proper cleaning filters. A clear confirmation of the ineffectiveness of Ukraine in matters of monitoring the condition and protection of the atmosphere, in comparison with European countries, was the scandal with the manipulation of exhausts of the Volkswagen concern (Dieselgate). Diesel engines use a catalyst with injection of a urea solution (AdBlue), or a catalytic converter built on the principle of accumulation of nitrogen oxides on a metal surface made of barium compounds . Synthetic urea in automotive catalysts transforms dangerous nitrogen oxides into harmless nitrogen and water . However, due to the software, during everyday use of the VW engines in question, this function remained disabled and the catalytic converter was simply removed. However, we see such cars, along with others, even more morally and technically outdated, on the roads of Ukraine every day. The practice of burning stubble in spring and autumn also leads to extreme consequences of air pollution. The morally outdated system of monitoring the state of the atmosphere, which has remained in Ukraine since Soviet times, is not able to show the real state of pollution, and the lack of proper control on the part of the state leads, in general, to the worsening of the situation every year. Environmental problems in the country in general, and in Poltava Oblast in particular, are the cause of the spread of cancer and high human mortality. Almost 80,000 people die of oncology in the country every year. According to 2020 data, the mortality of the population of Poltava Oblast from non-communicable diseases exceeds the average indicators for Ukraine: Ukraine – 1,597 people per 100,000 population, Poltava Oblast – 1,793 people per 100,000. Therefore, the relevance of the problem raised is extremely high, and it is necessary to start with monitoring air pollution and raising the problem at the national level, because most of the country's residents do not even know what kind of air they breathe at home and on the street.

「方」「圓」之內──多邊形颱風眼之探究

在本研究中,我們在正壓模式裡植入渦旋,當作實驗中的颱風眼,以不同的渦旋結構類型、渦度環及渦度比值進行實驗並觀察其變化。實驗結果顯示當渦旋結構的徑向渦度梯度變率存在正負的變化時,有機會導致正壓不穩定的發生,促進擾動而使渦旋形成多邊形結構。當渦旋內部的渦度梯度越大,則多邊形的形成越快但邊數越少;若渦旋外圈的強渦度區越薄,多邊形的形成越快且邊數越多。多邊形渦旋結構的演化則有可能發生「邊數合併」或「混合內縮」的情形,最終達到穩定或均質化的狀態。2017年泰利颱風行經台灣東北方海域時,我們從衛星雲圖中可觀察到颱風眼輪廓有多邊形變化,本文闡述此現象變化的歷程與可能的機制,進而希望在未來能利用此特點在颱風預報之領域中做出貢獻。

Co-movement!秋颱共伴效應之深入探討

共伴效應發生的颱風時常帶來嚴重災情,促使我們投入對秋颱共伴效應的分析。利用地面風場、輻合輻散場、衛星雲圖、測站氣壓雨量等統計資料以及颱風路徑等資料分析後,顯示在中央氣象局分類的五號、六號、九號路徑的颱風,發生共伴效應的比例較其他路經之颱風高。在風場與輻合輻散場之比較得知共伴會隨著颱風環流與東北季風相對位置的接近而產生增強的現象,再用地面天氣圖與雨量統計資料確認高壓靠海導致東北季風含水氣量的增加也會加強共伴雲帶降水。利用數十個颱風與六個測站雨量與風向的變化結果相互比較後,得知地形風向效應也會導致當地瞬時及總降雨量增減,而風向與地形走向之夾角越趨近於垂直影響雨量的效果則越顯著,而颱風路徑與共伴地形效應也有極大關聯性。最後利用高空比濕場驗證垂直上空氣舉升效應,確認風向輻合確實會造成氣塊舉升。

Schaubcylindrichnus生痕化石化學分析與生成環境探討

根據在北海岸地質考察所觀察到生痕化石種類分布,大部分生痕化石生成於濱海帶,可以推測大寮層及南港層在尚未抬升時,沉積於濱海帶的砂層沉積。另外,石底層雖然同為海相,但屬於海退時期,生物活動區域相對於海進時期較為深,因此生痕化石數量較少。將地質考察採集到Schaubcylindrichnus進行初步的外形觀察,推測其為S.coronus型態以及S.formosus型態,並將Schaubcylindrichnus與Ophiomorpha製成薄片進行比較,發現Schaubcylindrichnus與Ophiomorpha都是由石英與有機物組成,但Schaubcylindrichnus的顆粒比Ophiomorpha小且較為密集,而在Schaubcylindrichnus與Ophiomorpha中,管壁中與管壁內外的有機物含量有明顯差異,Schaubcylindrichnus管壁中的有機物較管壁內外少,而Ophiomorpha管壁中比較多,且可以發現大塊有機物包裹數塊石英的壁襯結構。

1910~2010年台灣附近板塊交界地帶地震能量觀察與比較

我們分析1910~2010年琉球及呂宋弧溝系統規模5.0以上的地震發生次數與能量釋放,並探討其特性。 經分析得知:(1)琉球系統地震發生次數及能量釋放變動不大。(2)將呂宋系統規模六地震大量發生的時間與規模七地震發生時間比對,發現1951及1999年部分規模六地震為規模七地震之餘震。若加入上述兩年規模六地震,則規模六地震大量發生之平均週期約為12年。(3)琉球系統能量大量釋放的週期約為30年,且其釋放的量越來越少。(4)呂宋系統大量釋放能量的週期約為十年。 (5)百年來,琉球系統的地震發生次數較呂宋系統多,在能量上則反之,還需深究是否為兩系統地質結構不同導致。(6) 若前次能量高峰釋放能量特別大,則距下次能量釋放高峰時間間隔較平均週期長。

統計分析大氣指數與洋流強度連動性探討

本研究分析北極震盪指數(AOI)、北大西洋震盪指數(NAOI)、北太平洋震盪指數(NPOI)、南方震盪指數(SOI)、與南極震盪指數(AAOI)相關性,並與海溫距平值進行相關係數計算,進而推求區域洋流與大氣指數間的連動性。 研究發現各指數間具一定程度關聯,如AOI與NAOI指數全年12個月均達中度相關,可能與指數計算方式有關。海溫距平與指數相關性探討,各指數可影響區域海溫,有些呈現大規模面積變化,且連續數月,甚至影響跨越半球。部分大氣指數與海溫距平值相關性具有季節差異,如反聖嬰時太平洋西岸(黑潮區域)冬季較正常低溫、夏季較正常高溫。祕魯涼流則受SOI影響主要在秋、冬季(9、10、11、12、1月),反聖嬰時祕魯涼流有增強趨勢,兩項推論均符合聖嬰現象理論。本研究目前僅用統計方式,呈現指數與海溫、海流關係,但指數與海溫間是否相關,還需要更多學理驗證。