全國中小學科展

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地球與環境科學

The impact of climate variability on infectious disease

Diarrhoea is an infectious disease that claims many lives (particularly among infants) and is known among many other infectious diseases, to have a relationship with climate. This projects quantifies this relationship by comparing health insurance treatment claims for diarrhoea and anti-diarrheal drug sales data from the private health sector with temperature and rainfall data provided by the South African Weather Service. The data were then analysed and show that incidence is highly seasonal and varies among regions with different seasonal climates. The results show that climate variability can explain 73% of diarrhea incidence variation with rainfall explaining 8% and minimum temperature explain the other 65 %. Preliminary predictions of future monthly percentage increases in incidence were then made for a series of time ranges. This project demonstrates that with predicted climate data one can predict future variations of diarrhoea allowing the health sector to be adequately prepared.

Neolema ogloblini- An agent in the biological control of Tradescantia

Tradescantia (Tradescantia fluminensis) is the worst weed in New Zealand. By smothering and shading out seedlings, Tradescantia prevents forest regeneration. Current control methods are ineffective and simultaneously cause harm to native forest. In 2011 Neolema ogloblini, a Brazilian beetle was introduced into New Zealand as a biological control for Tradescantia. To be successful in New Zealand, a country with different environmental factors, the beetles’ ranges of preference (temperature and light intensity) had to be investigated. A gender specific trait also identified, to enable desired sex ratios within founding populations to be selected. [18] This would ensure that the beetles are not released in areas of physiological stress, and can be optimised to have the greatest impact on Tradscantia. To establish how the intensity of light affects the distribution and amount of Tradescantia eaten by N.ogloblini a choice chamber investigation was conducted. Different layers of shade cloth provided a range of light intensities 150-3450Lux (likely to be found under forest canopy where Tradescantia is problematic). Thirty beetles of a range of sizes and approximately same maturity were randomly distributed through the chambers. Each chamber contained a shoot of Tradescantia with 5 leaves. After a 24hour period the number of beetles in each chamber were counted and the amount of surface area of the leaves eaten measured. The effect of temperature on the amount of leaf surface area eaten was investigated by selecting 90 beetles of a range of sizes and withholding food for 24hours. Five beetles were placed in each of three containers containing two leaves. Each trial container was precooled/warmed to the test temperature before the beetles were added. Leaves of a similar size, shape, mass and maturity were used. All leaves were genetically identical and collected from the same location. Sets of three containers were held in the dark at the following temperatures for 24hours: 9°C, 15°C, 20°C, 25°C, 30°C and 35°C. The surface area of leaf eaten at each temperature (mm2) was calculated. Lastly, microscopic dissections were conducted, using 32 beetles ranging in size, to establish if length (measured from the top of the head to the base of the abdomen) could be used as a phenotypic marker to identify beetle gender. While only a very weak positive relationship between increasing light intensity and the number of beetles was found a significantly higher area of leaf was eaten at a light intensity of 3450Lux compared to 150Lux. The amount of leaf area eaten is significantly reduced at temperatures of 15˚C and below, and significantly increased at 35˚C. There is no significant difference in the amount of leaf area eaten when comparing temperatures between 20-30˚C. Females have on average a larger body length (median=4.92mm) than the males (median=4.215mm). Therefore, sites with warmer temperatures in dappled light conditions (3450Lux) should be prioritised for the release of N.ogloblini, as this is the location in New Zealand at which their use as a biological control will be optimised. Beetle length can be confidently used to select desired gender ratios.

以HHT探討311日本海嘯對台灣各港的影響

本研究以希爾伯特-黃轉換 (Hilbert Huang Transform, HHT),來分析311日本海嘯對台灣各港的水位變動影響。利用HHT將各港驗潮站資料分解成數個本質模態函數 (Intrinsic Mode Functions, IMF),從中找出天文潮和海嘯影響的IMF。將主要的天文潮及趨勢線濾除後,可清楚看出海嘯影響水位的成份,進而分析各港口海嘯波抵達時間、振幅大小和主要頻率等。由 IMF 中可發現海嘯波來臨前海水水位退潮及急升狀況。此外,東部各港呈現出較為明顯的地震前導波(P波)所引起的高頻震盪波,與地震發生時間、P波傳遞速度、海水傳遞延遲及各港水位抬升時間都大致吻合,但較海嘯波到達時間大幅提前。上述研究結果,對瞭解海嘯波特性,將有所助益。

Geographic Belts for Hurricane Landfall Location Prediction

When predicting a hurricane’s landfall location, small improvements in accuracy result in large savings of lives, property, and money. The project’s purpose was to apply a breakthrough method that can predict the geographic location of a hurricane’s landfall with high accuracy. Researchers have known for a long time that there are strong correlations between a hurricane’s landfall location and the geographic regions its track passes through. However, no methods have been developed to mathematically and explicitly describe these correlations. Consequently, the correlations can only serve to meteorologists as vague guidelines for their guestimates and are not usable in making practical forecasts. By studying the correlations and performing numerical optimization on historical hurricane data, this research discovered a set of geographic belt regions in the Gulf of Mexico that can be used as landfall location predictors. When a hurricane passes through any one of these belt lines, a prediction can be made by extending the hurricane’s moving direction vector towards land – the intersection point of this extension line with the coastline is the predicted landfall location. This prediction method is simple and straightforward. It only uses basic measurements from meteorological satellites: the hurricane’s real-time locations and moving directions. In conclusion, when compared to existing methods, the predictive belt method (PBM) created in this research provides a landfall location forecast with higher accuracy. Verification with historical hurricane data demonstrated that the PBM’s average error is less than 50% of the National Hurricane Center models’ error.

利用都卜勒效應探討美濃地震的破裂方向性

本研究使用一規模較小的地震做為參考地震並得出其頻譜,將測站測得的美濃地震頻譜與之比較得出頻譜比,消除場址效應等非震源效應產生的影響,以探究美濃地震的破裂方向性。就每一對對震央方位角相差 180 度的地震而言,如果兩測站收到的頻譜比差距愈大,就表示地震的破裂方向越可能是該對測站的方向。 本研究的研究結果顯示測站距離對測站測得的頻譜比影響可忽略,且該方法用於尋找地震的破裂方向性確實可行。本研究得出美濃地震的破裂方向約在300到320度(即西偏北30~50度),且隨時間無明顯變化,與其他研究得出的結果相符。

金山神祕海岸浮石事件解密

浮石是一種多孔的火山碎屑岩,氣孔佔總體積很高的比例,因此能浮在水上。本研究針對臺灣新北市金山區神祕海岸所出露沉積層中的浮石進行探討,藉由閱讀文獻、實地考察、採樣、實驗分析等方式,來瞭解浮石的化學組成、礦物種類及可能形成機制與搬運途徑。依照化學成份分析及礦物種類比較結果顯示神祕海岸的浮石與日本、菲律賓的浮石較無關聯,最可能是來自台灣地區並由台灣北部大屯火山系或觀音山噴發所造成。至於其搬運方式,沉積物粒徑大小分析的結果顯示浮石是經由力量強大的海洋搬運作用攜至當地沉積。綜合上述,我們認為金山神祕海岸的浮石最有可能的生成方式為:1867年,由與大屯火山有相同岩漿系統的海底火山噴發出,接著此火山爆發所引發的海嘯將浮石帶至神祕海岸進行沉積。

地震與纜車的邂逅 Monitoring the Seismic Reduction and Vibration Resistance of Cable Car

本研究主要探討地震造成的纜車晃動,藉由自製的地震模擬器與纜車系統,探討各因素對纜車晃動之影響,設計纜車系統和車廂的減震裝置。研究結果顯示:一、地震時纜車斷電停駛位置愈靠近塔柱、相同長度纜繩上車廂個數較多、纜車重量較重、纜車臂較短,纜車晃動時間相對較短。二、所設計之減震裝置中,利用夾層中鋼珠轉動,使地震時只有外層纜車晃動而內層纜車輕微滑動的「雙層纜車」效果最佳。纜車系統塔柱則可參照建築物設置隔震元件,以減緩纜車晃動。本研究結果可望為未來應用之參考。

Microbial Film Power Generation 2.0 - It’s about to get cooler

This study demonstrates that microbial film power generation is a potentially viable source of alternative energy. This research occurred over a period of two years. In the first year (2016) I tested a new method of generating renewable energy, referred to as microbial film power generation. I showed that electricity could be captured from microbial decomposition using solid graphite plates (29cm x 20cm) placed in lightly decomposed muskeg (collected in northern British Columbia). In the second year (2017) the purpose was to increase the power output of the fuel cell, while also compacting the setup. Certain changes were made to the experimental set up, namely the use of spongy graphite felt in place of solid graphite plates, thus providing a larger surface area for microbial activity to occur. The new fuel cells made produced about twice as much power. Not only was the power output greater, but it was produced from a much smaller area: 7.82 mWh/cm2 on graphite felt, compared to 0.21 mWh/cm2 on graphite plates. In other words, graphite felt produced 37 times more power per unit area than graphite plates. Furthermore, it would appear that by removing the load from the fuel cell for approximately 24 hours, the fuel cell could essentially recharge. This may be due to microbial activity releasing more electrons onto the anode permitting a new cycle to take place. This would suggest that the system could naturally recharge itself.

The expansion of ticks in the valley of Poschiavo: a growing threat to the future?

In recent years, the ticks have reached the valley of Poschiavo and so far no study has been done to determine their diffusion. Recently, this presence has become a much discussed topic as these ticks can be carriers of pathogenes and represent a danger to humans. The goal of this work is to analyze the current situation in the valley of Poschiavo to understand in which areas the ticks are widespread, if they are carriers of pathogens and which factors could have an influence on their expansion. Several methods have been used for data collection. Ticks were found on ungulates killed during the high hunt in autumn 2016. In spring 2017, ticks were collected in various areas of the valley using the flag method that involves dragging a cotton cloth onto the ground. Some of the collected ticks were sent to a laboratory to identify the presence of the Borrelia burgdorferi, the pathogen responsible for Lyme borreliosis. To understand the evolution of the presence of ticks in the valley, the doctors and veterinarians were interviewed. Finally, to identify any climate changes related to the diffusion of ticks, the evolution of the tem-perature and relative humidity measured by two meteorological stations in the valley of Poschiavo since 1980 have been analyzed. Thanks to this study it was possible to highlight for the first time the presence in the valley of Poschiavo of ticks wich are bearer of the Borrelia burgdorferi. In fact, the bacterium was present in 26% of the analyzed ticks. Currently, the thicks populate the southern part of the valley, from the lake of Poschiavo to Campocologno, a small area in the central part of the valley and the area around Poschiavo and San Carlo. The interviews carried out showed that in recent years the ticks in the valley have increased and that the climate change could be a possible cause. In fact, since 1980 the temperature measured on the bottom of the valley has increased on average by 1.5 ° C and also the relative humidity has risen slightly. These changes could affect the diffusion of ticks in the valley of Poschiavo. In the future the temperatures will rise further and consequently the climate of the Poschiavo valley will most likely be more suited to the life of the ticks favoring their in-crease.

Lunar Tide Contribution to Thermosphere Weather

Internet search technology is a pervasively used utility that relies on techniques from the _eld of spectral graph theory. We present a novel spectral approach to investigate an existing problem: the critical group of the line graph has been characterized for regular nonbipartite graphs, but the general regular bipartite case remains open. Because of the ine_ectiveness of previous techniques in regular bipartite graphs, our approach provides a new perspective and aims to obtain the relationship between the spectra of the Laplacians of the graph G and its line graph bG. We obtain a theorem for the spectra of all regular bipartite graphs and demonstrate its e_ectiveness by completely characterizing the previously unknown critical group for a particular class of regular bipartite graphs, the incidence graphs of _nite projective planes with square order. This critical group is found to be Z2_(Z2q+2)q3􀀀1_(Zq2+q+1)q2+q􀀀1; where q is the order of the _nite projective plane.