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Desenvolvimento de um sensor óptico para a determinação de hidrocarbonetos aromáticos em águas empregando a espectroscopia no infravermalho próximo (NIR)da Silva Albuquerque, Jackson January 2004 (has links)
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Previous issue date: 2004 / A contaminação de águas subterrâneas e superficiais com poluentes orgânicos,
como os hidrocarbonetos presentes nos derivados de petróleo, causa um perigo
potencial à saúde das populações, tornando-se necessário à avaliação contínua dos
níveis de concentração destas substâncias. Para isso, é importante o desenvolvimento de
técnicas analíticas de baixo custo para o monitoramento contínuo e remoto de águas de
drenagem contaminadas e para o controle de efluentes industriais. Os hidrocarbonetos
aromáticos, como o benzeno, o tolueno, o etilbenzeno e os xilenos (BTEX), são os
constituintes da gasolina mais solúveis em água e, assim, podem se difundir com
facilidade no lençol freático. A espectroscopia na região do Infravermelho Próximo
(NIR) vem sendo adotada em várias áreas, como na agricultura, nas indústrias
alimentícias, farmacêuticas, químicas e petroquímicas, por ser uma técnica simples,
rápida, não-destrutiva e de baixo custo. O objetivo deste trabalho foi o desenvolvimento
de um sensor óptico à base de uma fase sensora de silicona acoplada a um
espectrofotômetro NIR (Infravermelho Próximo) para a determinação de BTEX em
amostras aquosas. Inicialmente foram avaliados diferentes tipos de silicona com
características apropriadas para construção do sensor, como transparência e
plasticidade, tendo-se selecionado a silicona à base de Polidimetilsiloxano (PDMS). Um
estudo dinâmico foi efetuado para avaliação do tempo de resposta da sonda para cada
constituinte dos BTEX, adotando-se a resposta da sonda como sendo de um sistema de
primeira ordem. Com este estudo, comprovou-se que o sistema tem um comportamento
de primeira ordem, tornando válido o modelo proposto para a difusão de
hidrocarbonetos aromáticos em silicona à base de PDMS. Os tempos de resposta para o
benzeno, tolueno, etilbenzeno e m-xileno foram de 0,48 h, 1,34 h, 2,00 h e 1,97 h,
respectivamente. Realizando-se uma análise por componentes principais dos dados
espectrais obtidos para cada composto individualmente, misturas contendo BTEX e
amostras contaminadas por gasolina e diesel, verificou-se que é possível distinguir se
uma amostra aquosa tem um dos aromáticos em estudo e se a mesma foi contaminada
por gasolina ou óleo diesel. Diante disso, pode-se concluir que o sistema sensor-NIR
pode ser utilizado para determinação qualitativa de hidrocarbonetos aromáticos em
águas superficiais e subterrâneas
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Changes in green liquor dregs after leaching with various acidic mediaSkagerkvist, Mio January 2017 (has links)
Green liquor dreg (GLD) is a residual product that could be a solution to the problem with acid rock drainage. More information about how this material reacts and is affected when in contact with acid rock drainage (ARD) is needed. Different acidic media was used to investigate trace element leaching and the possible spectral changes using FTIR. It was possible to detect changes between samples based on the exposure for different acidic conditions. Most peaks were found below 1 500 cm-1 which complicates the interpretation. For enabling the use of multivariate analysis the spectral data needed to be pre-treated and after this it was possible to see groupings and directions based on exposure. Different tendencies are seen for the trace elements, where some element leaching increased at lower pH and some elements decreased leaching at lower pH. This could partly be due to the formation of salts with low solubility such as gypsum and anglesite when leached with sulphuric acid.
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The Impact of Latency Jitter on the Interpretation of P300 in the Assessment of Cognitive FunctionYu, Xiaoqian 16 June 2016 (has links)
When stimuli processing time varies in an oddball paradigm, the latency of the P300 will vary across trials. In an oddball task requiring difficult response selections, as the variation of stimuli processing time increases, so does the variation of the P300 latency, causing latency jitters in the measurement. Averaging the P300 across different trials without adjusting this latency jitter will lead to diminished P300 amplitude, resulting in inaccurate conclusions from the data. Verleger et al. (2014) reported a diminished P300 amplitude in a difficult oddball task that required subjects to make response selections among stimuli that are difficult to distinguish, but his work did not correct for any latency jitter observed within his sample. The current study replicated the easy and hard oddball tasks conducted in Verleger et al.. Raw ERPs obtained from 16 subjects indicated a successful replication of the study. An examination of the behavioral data showed that there was substantial variation in the P300 during the hard oddball tasks, and a latency jitter correction was applied in the analysis. Results indicated that there was a significant increase in the amplitude of P300 after latency jitter correction, and that this P300 amplitude did not differ significantly between easy and hard oddball tasks. These results suggest that difficult decision requirement does not reduce the amplitude of the P300, and that latency jitter should be accounted for when analyzing data from tasks involving a difficult decision requirement.
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Video-based Fire Analysis and Animation Using EigenfiresNikfetrat, Nima January 2012 (has links)
We introduce new approaches of modeling and synthesizing realistic-looking 2D fire animations using video-based techniques and statistical analysis. Our approaches are based on real footage of various small-scale fire samples with customized motions that we captured for this research, and the final results can be utilized as a sequence of images in video games, motion graphics and cinematic visual effects. Instead of conventional physically-based simulation, we utilize example-based principal component analysis (PCA) and take it to a new level by introducing “Eigenfires”, as a new way to represent the main features of various real fire samples. The visualization of Eigenfires helps animators to design the fire interactively through a more meaningful and convenient way in comparison to known procedural approaches or other video-based synthesis models. Our system enables artists to control real-life fire videos through motion transitions and loops by selecting any desired ranges of any video clips and then the system takes care of the remaining part that best represent a smooth transition. Instead of tricking the eyes with a basic blending only between similar shapes, our flexible fire transitions are capable of connecting various fire styles. Our techniques are also effective for data compressions, they can deliver real-time interactive recognition for high resolution images, very easy to implement, and requires little parameter tuning.
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Identifying genetic biomarkers for diagnosis of prostate cancer in South African menSalukazana, Samkele Azola 24 February 2021 (has links)
Background and Aim: Prostate cancer (PCa) is the leading cancer diagnosis amongst South African men. The incidence of PCa is 68.0 per 100 000 Age Standardized Rate (ASR) and the mortality rates are 27.9 per 100 000 ASR; Globocan 2018. Diagnosis of PCa is based on a combination of digital rectal examination, prostate-specific antigen (PSA) and histology. Several biomarkers have been used to increase the sensitivity and specificity of PSA in distinguishing patients with PCa from those with benign prostatic hyperplasia (BPH). These include fractionated PSA, free/total PSA ratio, −2proPSA, prostate cancer antigen 3 and prostate health index amongst others. Biomarkers are needed to differentiate BPH from PCa due to a lack of specificity of these markers with PSA levels above 4.0 ng/ml. The aim of this study is to investigate gene expression patterns of South African men in 9 PCa and 10 BPH patients in order to distinguish between the two groups. Methods: Ethical approval was obtained (HREC 454/2012). Patients scheduled for transurethral resection of the prostate were recruited from the Western Cape. RNA was extracted from prostate tissue using the AllPrep DNA/RNA/miRNA Universal Kit (Qiagen). Complementary DNA was synthesized from RNA using the SuperScript IV VILO Master Mix (Thermo Fischer Scientific). Gene expression was analyzed with the Human Prostate Cancer RT2 Profiler PCR Array and SYBR Green Master Mix. Data were analyzed with the GeneGlobe RT2 and miScript PCR Array Data Analysis Centre from Qiagen. Results: The cohort included patients from different ethnic groups namely, Caucasians, Mixedand African ancestry. The PCa group has an age range from 56 to 75 years (mean 65) while the BPH group was slight older ranging from 60 to 76 years (mean 68). PSA levels range from 24 to 5000 ng/ml (mean 1252 ng/ml, median 185) for the PCa group and 11 to 58 ng/mL (mean 25 ng/ml, median 22) for the BPH group. The following genes were downregulated 2-fold in the PCa group with p values s <0.05; IGF1, PTEN, GSTP1, SOCS3, EGR3, GPX3, TIMP3, ZNF185, DKK3, PTGS2, FOXO1, ARNTL, TNFRSF10D, CCND1, and DLC1, upregulated genes included; CDH1, MKI67, TMPRSS2, ERG, CDKN2A, FASN, and AR but were not statistically significant. At a fold change threshold of 1.5, the following additional genes were downregulated in the PCa group with p values <0.05; DAXX, EGFR, RASSF1, SOX4, and TIMP2, upregulated genes were ACACA, AR, CDKN2A, ERG and FASN but were also not statistically significant. The study shows similarly differentially expressed genes as seen in international studies. Of note PTEN, MKI67 and FASN which are associated with poor prognosis. EGR3 was downregulated in our study and this has been associated aggressive disease and predict relapse after PCa treatment. This could explain the high mortality demonstrated in South African epidemiological studies. Conclusion: We identified a group of differentially expressed genes that have potential in distinguishing PCa and BPH patients with PSA values above 10 ng/ml. A larger population study is needed to further evaluate the clinical significance of our findings.
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Personalita u bodlinatých myší rodu Acomys / Personality in spiny mice (genus Acomys)Müllerová, Lenka January 2010 (has links)
The differences in behaviour of animals are not found only between species or populations but also between individuals within a population. If individuals differ in their behaviour constantly in time and across various situations, then we find diverse personality among them. The aim of my diploma thesis was to seek personality in spiny mice (Acomys cahirinus). For verification of stability of behaviour (of the same age) in various situations we tested animals in series of behavioural tests focusing on activity, exploration and anxiety. Every test was repeated twice with each individual in order to verify the stability of their behaviour in time. It was demonstrated that the behaviour of experimental animals is repeatable across different situations in time (the results of tests were correlated between each other as well as between two series), thus we confirmed the existence personality in the animals. However the personality does not participate on the results of individual tests by a great degree, its occurance is more evident from the series of more tests. Animals differ from each other primarily in coping with new situations. Keywords: personality, series of behavioural tests, PCA
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A Groundwater Vulnerability Assessment Method Using GIS and Multivariate Statistics - Gotland, Sweden.Pirnia, Seyed Amir January 2012 (has links)
Concentrations of microorganisms and chemical components in groundwater are serious threats for groundwater resources sustainability and contribute to technical and health problems. Recent studies and reports in Gotland revealed huge concerns about water quality in the area. In this master thesis a range of methods such as GIS and statistical analysis including multivariate analysis and non-parametric analysis, have been used in order to identify natural and human factors which affect groundwater contamination. Main focus of the study was on using existing data and available databases in analyses. Consequently, several important factors such as land use, overlaying soil cover, soil thickness, bedrock, elevation, distance to deformation and fracture zones and slope were evaluated considering 8 variables including micro-organisms and chemical components. The results clarified several significant factors which statistically affected the micro-biological and chemical components of groundwater. These relations can be used for development of risk maps which can be used in spatial planning.
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Students' Perceptions of Effectiveness and Engagement of a Performed Culture Approach and Collaborative Online International Learning in Japanese Language Practices in Higher EducationOkawara, Mayu 11 May 2021 (has links)
No description available.
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Knee Angles and Axes Crosstalk Correction in Gait, Cycling, and Elliptical Training ExercisesSkaro, Jordan M 01 May 2018 (has links) (PDF)
When conducting motion analysis using 3-dimensional motion capture technology, errors in marker placement on the knee results in a widely observed phenomenon known as “crosstalk” [1-18] in calculated knee joint angles (i.e., flexion-extension (FE), adduction-abduction (AA), internal-external rotation (IE)). Principal Component Analysis (PCA) has recently been proposed as a post hoc method to reduce crosstalk errors and operates by minimizing the correlation between the knee angles [1, 2]. However, recent studies that have used PCA have neither considered exercises, such as cycling (C) and elliptical training (E), other than gait (G) nor estimated the corrected knee axes following PCA correction. The hypothesis of this study is that PCA can correct for crosstalk in G, C, and E exercises but that subject-specific PCA corrected axes differ for these exercises.
Motion analysis of the selected exercises were conducted on 8 normal weight (body mass index (BMI) = 21.70 +/- 3.20) and 7 overweight participants (BMI = 27.45 +/- 2.45). An enhanced Helen Hayes marker set with 27 markers was used to track kinematics. Knee joint FE, AA, and IE angles were obtained with Cortex (Motion Analysis, Santa Rosa, CA) software and corrected using PCA to obtain corrected angles for each exercise. Exercise-specific corrected knee joint axes were determined by finding axes that reproduced the shank and ankle body vectors taken from Cortex when used with the PCA corrected angles. Then, PCA corrected gait axes were used as a common set of axes for all exercises to find corresponding knee angles. Paired t-tests assessed if FE-AA angle correlations changed with PCA. Multivariate Paired Hotelling’s T-Square tests assessed if the PCA corrected knee joint axes were similar between exercises. ANOVA was used to assess if Cortex angles, PCA corrected angles, and knee angles using PCA corrected gait axes were different.
Reduced FE-AA angle correlations existed for G (p<0.001 for Cortex and p=0.85 for PCA corrected), C (p=0.01 for Cortex and p=0.77 for PCA corrected), and E (p<0.001 for Cortex and p=0.77 for PCA corrected). Differences in the PCA corrected knee axes were found between G and C (p<0.0014). Then, differences were found between Cortex, PCA corrected, and C and E knee angles using the PCA corrected G axes (p<0.0056).
The results of this study suggest that if PCA is used to reduce crosstalk errors in motions other than G then it is recommended to adopt the use of a PCA corrected axes set determined from G to produce the PCA corrected angles.
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A Cosmic View of Life on Earth : Visualizing the relationship between species DNA in a threedimensional spaceSegolsson, Emma, Storesund, Linn January 2022 (has links)
This master thesis project is interdisciplinary between the fields of biology, visualization, and astrophysics. The project was conducted at the American Museum of Natural History in New York in collaboration with researchers from Basel, Switzerland. The goal of the project was to, with the help of OpenSpace, visualize and map the relation- ship between animal species by looking closely at their DNA and commuting the informa- tion to the general public. First, Openspace and the softwares existing functionality were examined to visualize the datasets used during the project. The two datasets explored in OpenSpace were: a cloud-based dataset known as The Barcode of Life Data (BOLD) Sys- tem, which contains 1.1 million DNA barcodes, and a dataset containing differences in human DNA to track human emigration. This project is the first time Openspace has been used to visualize fields other than space. As a starting point, the group of primates from the BOLD dataset was visualized. With the help of researchers in Switzerland, the indi- vidual DNA barcodes in the datasets were converted into three-dimensional positions that represent the relationship between species. This was achieved by applying dimensional- ity reduction techniques. In addition, various features were added to the dataset during the project, such as lineage, mutations, consensus sequences, endangered species, human emigration, and measures of polymorphism within species. With the help of Openspace, different visualization techniques could be investigated to visualize the different features in the two datasets and combine these visualizations into a story. The result is a story that highlights information from the dataset. The relationships between species are visualized using colors, glyphs, and volumes. The story takes an audience on a journey from the closest human relatives to the whole group of primates. The results were evaluated through interviews with four people to determine how the visualizations were interpreted. Further development of the project is to add other animal species in the visualizations to compare with the primates in the three-dimensional information space. A future goal of the project is to create a show about the subject of biology at the Hayden Planetarium at the Natural History Museum, which today has shows about space. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>
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