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A Novel Selection Process for the Conversion of Conventional Bacteria into Electrotrophs
The redox reactions of bacteria metabolism have been extrinsically studied. These mechanisms allow certain types of bacteria to be able to synthesize extremely valuable extracellular byproducts. Other types of bacteria are able to extract toxic metals from water by donating electrons directly to those aqueous metal ions, thus turning them into solid precipitates. However, the problem of these microorganisms is that their efficiency rates and production speeds are exceptionally low. This study focuses on the properties of electrotrophs, which are bacteria that can feed on pure electrons directly from an electrode (Rabaey et al 2010). Compared to normal organic-feeding bacteria, electrotrophs direct the majority of the electrons obtained to the production of metabolic byproducts (Nevin et al 2010). Therefore, when electrotrophs are employed in bioelectrochemical systems (BESs) their metabolic redox reaction efficiency rates are dramatically increased. This makes it possible to produce large quantities of valuable compounds such as hydrocarbons, plastics and medicine or efficiently remediating the environment (He et al 2016). Moreover, the usage of electricity as an energy source compared to conventional organic substrates is immensely cheaper (Rabaey et al 2010). However, not all bacteria are electrotrophs nor do all electrotrophs have favourable metabolic traits. Thus, there is a need for a novel procedure to turn conventional bacteria into electrotrophs which is a crucial step to making the BES an aggressive competitor in the sustainable energy industry.
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A Novel Spectroscopic-Chemical Sensor Using Photonic Crystals
Detection of harmful chemicals used in industrial complexes is crucial in order to create a safer environment for the workers. Presently, most chemical detectors used in workplaces are expensive, inefficient, and cumbersome. In order to address these deficiencies, a novel sensor was fabricated to produce a unique spectroscopic fingerprint for various toxic chemicals. The sensor was fabricated by depositing several layers of silica spheres (diameter ~250 nm) on a glass substrate using evaporation-based self assembly. As the spheres assemble to form a photonic crystal, they also create void (i.e., air) spaces in between them. Once the spheres assemble as a photonic crystal, a spectrometer was used to monitor the reflectivity. The spectrum had a high reflectivity at a specific wavelength, which is governed by the average index of refraction between the spheres and the void spaces. As a foreign chemical infiltrates into the photonic crystal, it occupies the void space, which results in an increase of the average index of refraction of the structure. Consequently, the peak wavelength of the reflectivity spectrum red-shifts, which then confirms the presence of a foreign substance. While the as-grown photonic crystal is able to detect chemicals, it is unable to differentiate between chemicals that have similar indices of refraction, such as ethanol and methanol. In order to detect chemicals with similar indices of refraction, five pieces of a single photonic crystal (i.e. five pixel device) were exposed to different silanes, which changed the surface chemistry of the silica spheres in the photonic crystal. In turn, the five pixel device was able to produce a unique chemical fingerprint for several chemicals, which can be calibrated to detect toxins in the workplace.
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.平面座標上長方形沙發旋轉問題之解的存在性
這篇報告要探討下列的「轉沙發的問題」是否有解?有一個長方形的沙發,如圖一,若要求每次只能以「四個頂點逆時針或順時針連續旋轉90度」的方式轉動,請問當長寬具備何種關係時,沙發經數次轉動後,剛好可以「轉」到相鄰的位置,如圖一,而且沙發坐人的正面方向仍保持不變呢?
我們把原問題看成「平面座標上長方形旋轉的數學問題」,再利用「平面座標、三角函數、複數、複數的極式表示及向量」等數學工具,導出符合題目要求的方程式,最後證出當長與寬的比值為正實數時,有下列的結果:
1.當長與寬比值為無理數時,此問題無解。
2.當長與寬比值是最簡分數時,若分子為奇數,此問題無解。
3.當長與寬比值是最簡分數時,若分子為偶數,分母為奇數,此問題有解。
4.在有解的情況下,我們可以找出特定轉法的最小值。
5.當長與寬比值是最簡分數時,若分子為偶數,分母為奇數,沙發可轉至A點座標為(αp,0) 的位置,其中 α∈Z,且沙發坐人的正面方向保持不變。
6.當長與寬比值是最簡分數時,若分子為奇數,分母為偶數,沙發可轉至A點座標為(0,βq) 的位置,其中 β∈Z,且沙發坐人的正面方向保持不變。
7當的長與寬比值為正實數時,可將沙發轉至A點的座標為(2αp + 2βq,2γp + 2qω)的位置,其中 α,β,γ,ω∈Z,且沙發坐人的正面方向保持不變。 In this paper we discuss the solution of rotating sofa problem as follows : The condition is : Merely allow to rotate the sofa several times by rotating 90 degrees clockwise or counterclockwise around the vertex. (maybe A, B, C, or D in Fig. 1) The question is : What’s the relationship between the length and the width of the sofa, if we request the sofa translated next to the original position with direction unchanged. (as shown in Fig. 1 with A’B’C’D’).
We take this problem as a mathematical one of rotating a rectangle in plane coordinates. Then we derive the desired equations by using the tools of plane coordinates, trigonometric functions, complex number, polar form of complex number, and vector. Finally, we prove that:
1. When the ratio of length and width is irrational, the problem has no solution.
2. When the length of sofa is odd in the ratio of length and width, the problem has no solution.
3. When the ratio of length and width is even, the problem has solutions.
4. When the solutions exist , we can find the minimum of the number of rotations.
5. When the ratio of length and width is an irreducible fraction, which has the even numerator and the odd denominator, the sofa can be rotated to the coordinate (αp,0)(α∈Z)which is the new position of A and keep the original position with direction unchanged.
6. When the ratio of length and width is an irreducible fraction, which has the odd numerator and the even denominator, the sofa can be rotated to the coordinate (0,βq)(β∈Z) which is the new position of A and keep the original position with direction unchanged.
7. When the ratio of length and width is a real positive number, the sofa can be rotated to the coordinate (2αp + 2βq,2γp + 2qω)(α,β,γ,ω∈Z)which is the new position of A and keep the original position with direction unchanged.
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A New Generation Colorimetric Method for Lead Analysis: APTAMER MODIFIED GOLD NANOPARTICLES
Lead is a toxic element which is used in the production of chemicals, dyes, accumulators and various industrial areas. It may cause complications even extended to death when it is taken consistently in high amounts. Lead poisoning is in the first place among the occupational diseases. It is gaining importance to develop new and sensitive methods for lead analysis. Because lead poisoning can progress without any symptoms and poisoning level (10µg/dL) is low. Disadvantages of the systems used for lead analysis are such as longer detection time, being expensive and difficult to implement. The aim of this project is to develop a new generation method in order to detect lead in blood, based on aptamer modified gold nanoparticles. We detected the lead in terms of color change obtained in gold nanoparticle solutions, with composite biochemosensor that is prepared with 20 & 80 nm sized gold nanoparticles and TBA(Thrombin Binding Aptamer). While immobilizing TBA to the gold nanoparticles, we benefitted from the magnificent surface affinity of the –SH (Thiol) groups that modified to the TBA. Gold nanoparticles that are used in development of our biotechnological method do not stimulate the immune system. The preparation of aptamers in completely sterile medium provides us to use our system in the lead detection of blood. Our method can also be used in the lead detection of mediums such as waste water, food and soil. We have developed a biochemosensor that can be used to detect the presence and absence of Pb2+ by taking into consideration the toxic effect in the human body. Also we detected the presence of lead colorimetrically, in low concentration levels and wide interval values of 4.4 – 11 µg/dL. The developed system is first that; it provides TBA to be used with its complimentary sequence detects the presence of lead colorimetrically and can be used in physiological media such as blood. Also our system can detect lead in amounts that are lower than the poisoning threshold.
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Antiviral Therapy for Hepatitis C Virus (HCV): Black Mustard Seeds
Hepatitis C Virus (HCV) is an RNA virus, which is considered the main cause of progressive chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. The number of the patients who are infected with this sleeping virus is increasing rapidly every year, as the unsuitability of the current therapy – interferon α and ribavirin – for most of the genotypes is the main cause of these high rates. Hence, the recent researches are focusing on finding out a new immunotherapy to affect this virus. In this research work, Black Mustard (Brassica nigra) has been used as powdered spice samples to prepare aqueous extracts; One of the included phytochemicals in the black mustard; glucosinolates and their hydrolysis products, was proposed to be used for the HCV patients to prevent the virus progression. Also, the Isothiocyanates are shown with chemotherapeutic and anti-tumor properties. Moreover, some of the structure-related isothiocyanates have the ability to induce the enzyme paraoxonase-1 (PON-1) that is considered hepato-protective agent against liver impairment, inflammation, fibrosis and liver disease mediated by monocyte chemoattractant protein-1 (MCP-1), and is thought to affect the entry of the virus into the hepatocytes. The effect of the black mustard and the produced myrosinase enzyme on the HCV RNA replication is still unknown. In conclusion, the black mustard is thought to affect the progression and the fluidity of the HCV envelope resulting in impairment of viral binding and fusion.
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Sustainable Graphene Oxide Support for Ruthenium Catalysts to Improve the Efficiency of the Hydrodesulfurization of Thiophenes
沙烏地阿拉伯 is the largest oil exporter in the world. 64,000,000 tons of sulfur oxides are produced every year through the combustion of organic sulfur compounds in the oil industry. This leads to several environmentally serious problems, including air pollution. This research provides a novel strategy to utilize natural-based Graphene Oxide (GO) as a support for ruthenium (Ru/GO) to functionalize as a green catalyst for hydrodesulfurization. Physical activation of camel bone samples was carried out by carbonizing them at 500oC to produce camel bone charcoal. Modified hammer’s method was employed for GO production, followed by doping of ruthenium in a simple synthesis step. The prepared catalyst has been characterized by XRD, SEM and EDX techniques. Thiophene and 3-methylthiophene were used as model compounds in the hydrodesulfurization process. The catalytic reactions were carried out at atmospheric pressure in a continuous up-flow fixed-bed quartz reactor. The composition of the sulfur containing gaseous products was analyzed by gas chromatography. The product distribution achieved for thiophene was 3-6% butadiene and 76-77% butane. And for 3-methylthiophene, it was 32.3% of pentaned 1-pentene and 2-pentene and the selectivity percentage was 45%. Ru/GO has been found to be an excellent catalyst of thiophene and 3- methylthiophene hydrodesulfurization and is a considerable improvement when compared to the commercially available catalysts. The prepared catalyst shall potentially lead to the reduction of sulfur pollution in the future. The positive effect on the environment could be substantial.
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在 1940 年代,Bouwkamp 提出一系列有關如何將矩形切割成若干個正方形的研究報告,但是如何找出正方形個數最少的方法仍是長久以來懸而未決的問題。在本研究報告中,首先引進「四角切割」的方法,並結合輾轉相除法的概念,來研究矩形的切割問題。我們的方法能大幅度降低正方形的個數,也適合做為此問題的上界函數。有關如何在長方體中切割出正立方體的組合,我們也將輾轉相除法的概念延伸到三維空間,進而建立所切割出最少個正立體數的一個上界模式。此外,藉由四角切割概念的延伸,我們也發現這個上界亦可再予修正。 In 1940’s, Bouwkamp proposed the study of dissecting squares from rectangles. Among the study, the problem of the least number of dissected squares has been open for decades. In this project, we first propose a corner dissection method, associated with the famous Euclidean algorithm. By reducing nearly three fourths of the number dissected by the primitive Euclidian algorithm, our method indeed establish a suitable upper bound of the minimal number of dissected squares from the given rectangles Meanwhile, the Euclidean algorithm has also been considered to dissect the cubes from cuboids. We analyze the fundamental properties of the method and establish a prototype of upper bound function for the minimal number of dissected cubes. Moreover, the method of corner dissection has also been implemented for some cuboids, which also exhibits the acceptable improvement being a suitable upper bound.
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金門西南濱海地區待霄花〈OenotheradrumnodiiHook〉的族群分布與型態適應之觀察
待宵花(Oenothera drumnondii Hook)屬於柳葉菜科(Onagraceae)、月見草屬(Oenothera)的植物,原產於北美洲,是金門的「歸化植物」。本項研究自 90 年 6 月至 91 年 5 月,就金門西南濱海地區待宵花族群分布及變化、生長環境與其形態上的適應進行調查。發現待宵花生長在海濱沙丘,其主要族群分布地有六處,以湖下海堤內的族群最大。族群密度在六月達最高峰,而在十二月時最小。4?8 月是待宵花盛開的月份,而 12?2 月則極少開花。待宵花對海濱沙地的生長環境適應性很強,經觀察發現它們以其植物體多種特殊的形態與構造生長在乾旱的沙地上,在金門海濱沙地少有植物可與它們競爭。
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兩條不平行的相交直線L1、L2,交角θ度。今有一不在L1、L2 的點P0,作關於L1的對稱點P1。P1又作關於L2的對稱點P2,P2又作關於L1的對稱點P3??如此反覆對L1、L2 做對稱點,當Pn 的n= 2π/g.c.d(π,Θ),則Pn 會重合P0。另外對L1、L2 形成的所有對稱點會位在同一個圓上
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微生物源尿酸氧化酶催化尿酸降解與高尿酸檢測
尿酸氧化酶參與嘌呤代謝機制,然人類尿酸氧化酶基因已退化,易使過量尿酸沉積於關節造成痛風,因此微生物源尿酸氧化酶具極高研發價值。 本研究針對微生物源酵素進行基因體探勘,篩選出抗輻射奇異球菌(Deinococcus radiodurans)及耐熱雙球桿菌(Thermobispora bispora)源尿酸氧化酶基因,取得尿酸氧化酶重組蛋白質進行酵素活性測定、熱穩定分析、蛋白質結構解析、酵素對金屬離子耐受性分析與尿酸檢測應用。抗輻射奇異球菌源酵素於30℃催化速率較過去報導之酵素佳,而耐熱雙球桿菌源酵素於70℃催化效率與熱穩定性仍佳。解析耐熱雙球桿菌源酵素結構發現羧基端具特異性構型,推測與熱穩定性有關。本研究的兩種尿酸氧化酶,可分別作為降解尿酸的速效及緩解型藥物,並開發成快速檢測尿酸的簡易方法。
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FABRICATION AND CHARACTERIZATION OF CARBON NANOTUBE DOPED PHOTOVOLTAIC CELLS
Nowadays, the increase in population and the rapid depletion of nonrenewable energy sources brings the need for energy. In this case, scientists are forced to develop technologies by using renewable energy sources. Sun is the unlimited and renewable energy source. Organic solar cells absorb the light from the sun by the active polymer layer and transform it into electrical power. Organic solar cells are advantageous than inorganic ones because of being low-cost, easy-to-use and proper for large scale applications. In this project, it is aimed to produce organic solar cells by using specific amounts of carbon nanotube (CNT) doping. According to this aim, it is detected by using the fluorescence spectroscopy that CNTs can be used in organic solar cells. Later, the homogenous distribution of doping SWCNT into donor material was displayed by AFM, and correct proportion of SWCNTs are chosen by those images. In order to increase the efficiency of organic solar cell SWCNT doped P3HT was used as donor molecule. The acceptor molecule was PCBM in here. Surface characterization of prepared samples was made by Atomic Force Microscope (AFM), while electrical characterization of them is done with airless environment cabin (glove-box) system in nitrogen environment. As a result, devices prepared with addition of cyclohexanone in P3HT: SWCNT%:PCBM new load paths to carbon nanotubes were provided, as a result of the measurements short circuit current obtained was raised from the reference to 53%. The best yields were found as 2.24% in 0.2% SWCNT doped devices. This result shows efficiency is healed according to the reference rate as 64%. In this study, certain amounts of carbon nanotube doped organic solar cells were produced, which are highly efficient rather than traditional organic solar cells and low cost, easy-to-produce rather than inorganic solar cells, by using environmentally friendly materials.
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The Effect of Hands Free - Cell Phone Conversation on Visual Fields
It is a known fact that using a cell phone while driving can lead to reckless driving. According to research done by the World Health Organisation (2011) thousands of car accidents occur worldwide, each day, due to cell phone use whilst driving. Many of these car accidents result in serious injury or death of drivers, passengers or pedestrians. According to the Automobile Association (2012), cell phones are the number one cause of traffic accidents in South Africa. The high rate of car accidents due to cell phone use has led to legislation being passed, in most countries, banning hand-held cell phone use while driving. Hands-free phone equipment is not prohibited as it is widely regarded as a safe means of making and taking a phone call while behind the wheel. The purpose of this study was to show that the act of talking on a cell phone and not the method of talking (hand-held versus hands-free) increases accident probability. This study used a Friedman Visual field analyser which measures subject’s visual fields with and without engaging in hands-free cellular conversation. The results showed a significant constriction of the visual fields when subjects were conversing on a cell phone. These results were and can be explained by the fact that the test subject experiences cognitive distraction. Cognitive distraction occurs because the driver has to divide his/her attention between the cell phone conversation and the tasks relating to driving. These results have significant ramifications for road safety in a driving environment.
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