933 resultados para L71 - Mining, Extraction, and Refining:


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There is limited scientific knowledge on the composition of human odor from different biological specimens and the effect that physiological and psychological health conditions could have on them. There is currently no direct comparison of the volatile organic compounds (VOCs) emanating from different biological specimens collected from healthy individuals as well as individuals with certain diagnosed medical conditions. Therefore the question of matching VOCs present in human odor across various biological samples and across health statuses remains unanswered. The main purpose of this study was to use analytical instrumental methods to compare the VOCs from different biological specimens from the same individual and to compare the populations evaluated in this project. The goals of this study were to utilize headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC/MS) to evaluate its potential for profiling VOCs from specimens collected using standard forensic and medical methods over three different populations: healthy group with no diagnosed medical or psychological condition, one group with diagnosed type 2 diabetes, and one group with diagnosed major depressive disorder. The pre-treatment methods of collection materials developed for the study allowed for the removal of targeted VOCs from the sampling kits prior to sampling, extraction and analysis. Optimized SPME-GC/MS conditions has been demonstrated to be capable of sampling, identifying and differentiating the VOCs present in the five biological specimens collected from different subjects and yielded excellent detection limits for the VOCs from buccal swab, breath, blood, and urine with average limits of detection of 8.3 ng. Visual, Spearman rank correlation, and PCA comparisons of the most abundant and frequent VOCs from each specimen demonstrated that each specimen has characteristic VOCs that allow them to be differentiated for both healthy and diseased individuals. Preliminary comparisons of VOC profiles of healthy individuals, patients with type 2 diabetes, and patients with major depressive disorder revealed compounds that could be used as potential biomarkers to differentiate between healthy and diseased individuals. Finally, a human biological specimen compound database has been created compiling the volatile compounds present in the emanations of human hand odor, oral fluids, breath, blood, and urine.

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I conducted this study to provide insights toward deepening understanding of association between culture and writing by building, assessing, and refining a conceptual model of second language writing. To do this, I examined culture and coherence as well as the relationship between them through a mixed methods research design. Coherence has been an important and complex concept in ESL/EFL writing. I intended to study the concept of coherence in the research context of contrastive rhetoric, comparing the coherence quality in argumentative essays written by undergraduates in Mainland China and their U.S. peers. In order to analyze the complex concept of coherence, I synthesized five linguistic theories of coherence: Halliday and Hasan's cohesion theory, Carroll's theory of coherence, Enkvist's theory of coherence, Topical Structure Analysis, and Toulmin's Model. Based upon the synthesis, 16 variables were generated. Across these 16 variables, Hotelling t-test statistical analysis was conducted to predict differences in argumentative coherence between essays written by two groups of participants. In order to complement the statistical analysis, I conducted 30 interviews of the writers in the studies. Participants' responses were analyzed with open and axial coding. By analyzing the empirical data, I refined the conceptual model by adding more categories and establishing associations among them. The study found that U.S. students made use of more pronominal reference. Chinese students adopted more lexical devices of reiteration and extended paralleling progression. The interview data implied that the difference may be associated with the difference in linguistic features and rhetorical conventions in Chinese and English. As far as Toulmin's Model is concerned, Chinese students scored higher on data than their U.S. peers. According to the interview data, this may be due to the fact that Toulmin's Model, modified as three elements of arguments, have been widely and long taught in Chinese writing instruction while U.S. interview participants said that they were not taught to write essays according to Toulmin's Model. Implications were generated from the process of textual data analysis and the formulation of structural model defining coherence. These implications were aimed at informing writing instruction, assessment, peer-review, and self-revision.

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My paper discusses three different ways in which stray dogs have been intertwined with ideologies of economic and urban development in Romania. I categorize results from archival and ethnographic research under three major time periods: early socialism, late socialism, and post-socialism. During early socialism stray dogs were seen to be damaging the soviet economy by killing species that humans could also hunt, like rabbits. During late socialism, stray dogs appeared as the enemies of the communist city, and the department of urban sanitation was given orders to poison dogs with strychnine. Finally, the increasing number of stray dogs in Bucharest after the collapse of communism was seen as a direct result of former communist demolitions, and was also taken as a sign of the collapsing state. Through such examples my paper discusses how the state and particular population groups have seen dogs as parts of an unwanted and dangerous nature, rather than a species that needs to be protected. I argue that distinctions of nature and culture have served discourses of civilization and the view of Bucharest as a model socialist, and then European city. Throughout my paper I juxtapose the treatment of stray dogs with other, more “valued” urban natures like the protection of parks, the wide-spread hobby of pigeon breeding during socialist years, the most recent debate on saving the rural area of Rosia Montana from non-environmentally friendly methods of gold extraction, and the current trend of healthy eating and living.

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Purpose: Metabolic syndrome (MetS) is associated with the development of cardiovascular disease (CVD) and type 2 diabetes. Decreases in circulating adiponectin and ghrelin have been associated with MetS. Our primary aim was to evaluate the relationship of MetS with adiponectin and ghrelin for Cuban Americans with and without type 2 diabetes. Methods: Cross-sectional study of 367 adults, self identified as Cuban extraction and randomly recruited from a mailing list of Broward and Miami-Dade counties. Fasted whole blood for adiponectin (ADPN) was collected using K3EDTA tubes and measured by ELISA. Ghrelin was assayed with fasted blood plasma by Enzyme Immunometric Assay. MetS and 10-year risk for coronary heart disease (CHD) were determined using the ATP III criteria. Results: Adiponectin (F=51.8, R2 =0.21 p<0.001) and ghrelin (F=12.77, R 2 =0.06, p<0.001) differed by diabetes status (ANOVA) not age and gender. In stepwise linear regression models triglyceride levels ≥ 150 mg/dL negatively corresponded (coefficient = -0.23) with ghrelin levels for persons without diabetes (F=7.45, R2 =0.053, p=0.007); abdominal obesity and fasting plasma glucose predicted high sensitivity C-reactive protein (hs-CRP) for persons with and without diabetes (F=16.3, R2 = 0.144, p <0.001). Conclusion: Low ghrelin levels were associated with MetS regardless of diabetes status. High adiponectin levels were related to a low probability for those without diabetes only. There was a positive association of hs-CRP with BMI, MetS and number of MetS components.

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This study focuses on empirical investigations and seeks implications by utilizing three different methodologies to test various aspects of trader behavior. The first methodology utilizes Prospect Theory to determine trader behavior during periods of extreme wealth contracting periods. Secondly, a threshold model to examine the sentiment variable is formulated and thirdly a study is made of the contagion effect and trader behavior. The connection between consumers' sense of financial well-being or sentiment and stock market performance has been studied at length. However, without data on actual versus experimental performance, implications based on this relationship are meaningless. The empirical agenda included examining a proprietary file of daily trader activities over a five-year period. Overall, during periods of extreme wealth altering conditions, traders "satisfice" rather than choose the "best" alternative. A trader's degree of loss aversion depends on his/her prior investment performance. A model that explains the behavior of traders during periods of turmoil is developed. Prospect Theory and the data file influenced the design of the model. Additional research included testing a model that permitted the data to signal the crisis through a threshold model. The third empirical study sought to investigate the existence of contagion caused by declining global wealth effects using evidence from the mining industry in Canada. Contagion, where a financial crisis begins locally and subsequently spreads elsewhere, has been studied in terms of correlations among similar regions. The results provide support for Prospect Theory in two out of the three empirical studies. The dissertation emphasizes the need for specifying precise, testable models of investors' expectations by providing tools to identify paradoxical behavior patterns. True enhancements in this field must include empirical research utilizing reliable data sources to mitigate data mining problems and allow researchers to distinguish between expectations-based and risk-based explanations of behavior. Through this type of research, it may be possible to systematically exploit "irrational" market behavior.

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A compilation of chemical analyses of Pacific Ocean nodules using an x-ray fluorescence technique. The equipment used was a General Electric XRD-5 with a tungsten tube. Lithium fluoride was used as the diffraction element in assaying for all elements above calcium in the atomic table and EDDT was used in conjunction with a helium path for all elements with an atomic number less than calcium. Flow counters were used in conjunction with a pulse height analyzer to eliminate x-ray lines of different but integral orders in gathering count data. The stability of the equipment was found to be excellent by the author. The equipment was calibrated by the use of standard ores made from pure oxide forms of the elements in the nodules and carefully mixed in proportion to the amounts of these elements generally found in the manganese nodules. Chemically analyzed standards of the nodules themselves were also used. As a final check, a known amount of the element in question was added to selected samples of the nodules and careful counts were taken on these samples before and after the addition of the extra amount of the element. The method involved the determination and subsequent use of absorption and activation factors for the lines of the various elements. All the absorption and activation factors were carefully determined using the standard ores. The chemically analyzed samples of the nodules by these methods yielded an accuracy to at least three significant figures.

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Industrial activities like mining, electroplating and the oil extraction process, are increasing the levels of heavy metals such as Cu, Fe, Mg and Cd in aquatic ecosystems. This increase is related to the discharge of effluents containing trace of this elements above the maximum allowed by law. Methods such as ion exchange, membrane filtration and chemical precipitation have been studied as a means of treatment of these metals contamination. The precipitation of metals using anionic surfactants derived from carboxylic acids emerged as an alternative for the removal of metals from industrial effluents. The reaction between bivalent ions and these types of surfactants in aqueous solution leads to the formation of metal carboxylates, which can precipitate in the form of flakes and are subsequently removed by a process of decantation or simple filtration. In this work the metals extraction is performed by using the surfactant sodium hexadecanoate as extracting agent. The main purpose was to study the effect of temperature, solution pH, and concentration of surfactant in the metal removal process. The statistical design of the process showed that the process is directly dependent to changes in pH and concentration of surfactant, but inversely proportional and somewhat dependent to temperature variation, with the latter effect being considered negligible in most cases. The individual study of the effect of temperature showed a strong dependence of the process with the Kraft point, both for the surfactant used as extracting agent, as for the surfactant obtained after the reaction of this surfactant with the metal. From data of temperatures and concentrations of the surfactant was possible to calculate the equilibrium constant for the reaction between sodium hexadecanoate and copper ions. Later, thermodynamic parameters were determined, showing that the process is exothermic and spontaneous.

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The Brejuí Mine, situated in the municipality of Currais Novos (RN), was responsible for the local economy growth between the years of 1943 and 1990, causing the interest of miner's working class to its urban center. After the end of scheelita extraction, the mine became a "theme park", in 2004. The company left its mark on the city by building several monuments in reference to the mining activity and the company's founder, Tomaz Salustino. However, there are no written records that describe such activities on its early years, nor their pioneers in the mining subject. Therefore, it is important to investigate the miner’s memories and ask if, along the more than five decades that lasted the heyday of mining, an identity linked to the profession was built; the extent to which workers make reference to this history as membersand what are the symbols that are being triggered in the development of a working class identity. Further, I investigate what memory was mad concerning the pioneers, mostly farmers attracted by miner work. To do so, I make use of audiovisual archival resources and oral records of the interlocutors that were filmed in the preparations of the documentary “Lembranças de velhos garimpeiros". We have noticed that, in the script of the official history of the Brejuí Mine, the "boss" figure overlaps the workers and that the forms patronage, originated from the rural world, followed punctuating the social relations in the mine. Today, with the resumption of the mining activity, it is possible that the strengthening of the working class and the Seridó miner identity desire reborn.

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In States of Paraíba (PB) and Rio Grande do Norte (RN), northeast of Brazil, the most significant deposits of non-metallic industrial minerals are pegmatites, quartzites and granites, which are located in Seridó region. Extraction of clay, quartz, micas and feldspars occurs mainly in the cities of Várzea (PB), OuroBranco (RN) and Parelhas (RN). Mining companies working in the extraction and processing of quartzite generate large volumes of waste containing about 90% SiO2 in their chemical composition coming from quartz that is one of the basic constituents of ceramic mass for the production of ceramic coating. Therefore, this work evaluates the utilization of these wastes on fabrication of high-quality ceramic products, such as porcelain stoneware, in industrial scale. Characterization of raw materials was based on XRF, XRD, GA, TGA and DSC analysis, on samples composed by 57% of feldspar, 37% of argil and 6% of quartzite residues, with 5 different colors (white, gold, pink, green and black). Samples were synthesized in three temperatures, 1150°C, 1200°C and 1250°C, with one hour isotherm and warming-up tax of 10°C/min. After synthesizing, the specimens were submit to physical characterization tests of water absorption, linear shrinkage, apparently porosity, density, flexural strain at three points. The addition of 6% of quartzite residue to ceramic mass provided a final product with technological properties attending technical norms for the production of porcelain stoneware; best results were observed at a temperature of 1200°C. According to the results there was a high iron oxide on black quartzite, being their use in porcelain stoneware discarded by ethic and structural question, because the material fused at 1250°C. All quartzite formulations had low water absorption when synthesized at 1200°C, getting 0.1% to 0.36% without having gone through the atomization process. Besides, flexural strain tests overcame 27 MPa reaching the acceptance limits of the European Directive EN 100, at 1200°C synthesizing. Thus, the use of quartzite residues in ceramic masses poses as great potential for the production of porcelain stoneware.

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Acknowledgements The authors would like to thank, Estelle Payerne (article screening, data extraction and bias assessment); Trish Boyton (article retrieval and screening) and Laura Cawley (search terms and title screening) for their invaluable help in conducting this systematic review. Funding The research was funded by the UK National Institute for Health Research Health Technology Assessment Programme.

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The full-scale base-isolated structure studied in this dissertation is the only base-isolated building in South Island of New Zealand. It sustained hundreds of earthquake ground motions from September 2010 and well into 2012. Several large earthquake responses were recorded in December 2011 by NEES@UCLA and by GeoNet recording station nearby Christchurch Women's Hospital. The primary focus of this dissertation is to advance the state-of-the art of the methods to evaluate performance of seismic-isolated structures and the effects of soil-structure interaction by developing new data processing methodologies to overcome current limitations and by implementing advanced numerical modeling in OpenSees for direct analysis of soil-structure interaction.

This dissertation presents a novel method for recovering force-displacement relations within the isolators of building structures with unknown nonlinearities from sparse seismic-response measurements of floor accelerations. The method requires only direct matrix calculations (factorizations and multiplications); no iterative trial-and-error methods are required. The method requires a mass matrix, or at least an estimate of the floor masses. A stiffness matrix may be used, but is not necessary. Essentially, the method operates on a matrix of incomplete measurements of floor accelerations. In the special case of complete floor measurements of systems with linear dynamics, real modes, and equal floor masses, the principal components of this matrix are the modal responses. In the more general case of partial measurements and nonlinear dynamics, the method extracts a number of linearly-dependent components from Hankel matrices of measured horizontal response accelerations, assembles these components row-wise and extracts principal components from the singular value decomposition of this large matrix of linearly-dependent components. These principal components are then interpolated between floors in a way that minimizes the curvature energy of the interpolation. This interpolation step can make use of a reduced-order stiffness matrix, a backward difference matrix or a central difference matrix. The measured and interpolated floor acceleration components at all floors are then assembled and multiplied by a mass matrix. The recovered in-service force-displacement relations are then incorporated into the OpenSees soil structure interaction model.

Numerical simulations of soil-structure interaction involving non-uniform soil behavior are conducted following the development of the complete soil-structure interaction model of Christchurch Women's Hospital in OpenSees. In these 2D OpenSees models, the superstructure is modeled as two-dimensional frames in short span and long span respectively. The lead rubber bearings are modeled as elastomeric bearing (Bouc Wen) elements. The soil underlying the concrete raft foundation is modeled with linear elastic plane strain quadrilateral element. The non-uniformity of the soil profile is incorporated by extraction and interpolation of shear wave velocity profile from the Canterbury Geotechnical Database. The validity of the complete two-dimensional soil-structure interaction OpenSees model for the hospital is checked by comparing the results of peak floor responses and force-displacement relations within the isolation system achieved from OpenSees simulations to the recorded measurements. General explanations and implications, supported by displacement drifts, floor acceleration and displacement responses, force-displacement relations are described to address the effects of soil-structure interaction.

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\abstract

This dissertation seeks to explain the role of governmental and non-governmental actors in increasing/reducing the emergence of intergroup conflict after war, when group differences have been a salient aspect of group mobilization. This question emerges from several interrelated branches of scholarship on self-enforcing institutions and power-sharing arrangements, group fragmentation and demographic change, collective mobilization for collectively-targeted violence, and conflict termination and the post-conflict quality of peace. This question is investigated through quantitative analyses performed at the sub-national, national, and cross-national level on the effect of elite competition on the likelihood of violence committed on the basis of group difference after war. These quantitative analyses are each accompanied by qualitative, case study analyses drawn from the American Reconstruction South, Iraq, and Cote d'Ivoire that illustrate and clarify the mechanisms evaluated through quantitative analysis.

Shared findings suggest the correlation of reduced political competition with the increased likelihood of violence committed on the basis of group difference. Separate findings shed light on how covariates related to control over rent extraction and armed forces, decentralization, and citizenship can lead to a reduction in violence. However, these same quantitative analyses and case study analysis suggest that the control of the state can be perceived as a threat after the end of conflict. Further, together these findings suggest the political nature of violence committed on the basis of group difference as opposed to ethnic identity or resource scarcity alone.

Together, these combined analyses shed light on how and why political identities are formed and mobilized for the purpose of committing political violence after war. In this sense, they shed light on the factors that constrain post-conflict violence in deeply divided societies, and contribute to relevant academic, policy, and normative questions.

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Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs) that have been heavily used in consumer products such as furniture foams, plastics, and textiles since the mid-1970’s. BFRs are added to products in order to meet state flammability standards intended to increase indoor safety in the event of a fire. The three commercial PBDE mixtures, Penta-, Octa-, and DecaBDE, have all been banned in the United States, however, limited use of DecaBDE is still permitted. PBDEs were phased out of production and added to the Stockholm Convention due to concerns over their environmental persistence and toxicity. Human exposure to PBDEs occurs primarily through the inadvertent ingestion of contaminated house dust, as well as though dietary sources. Despite the phase-out and discontinued use of PBDEs, human exposure to this class of chemicals is likely to continue for decades due to the continued use of treated products and existing environmental reservoirs of PBDEs. Extensive research over the years has shown that PBDEs disrupt thyroid hormone (TH) levels and neurodevelopmental endpoints in rodent and fish models. Additionally, there is growing epidemiological evidence linking PBDE exposure in humans to altered TH homeostasis and neurodevelopmental impairments in children. Due to the importance of THs throughout gestation, there is a great need to understand the effects of BFRs on the developing fetus. Specifically, the placenta plays a critical role in the transport, metabolism, and delivery of THs to the fetal compartment during pregnancy and is a likely target for BFR bioaccumulation and endocrine disruption. The central hypothesis of this dissertation research is that BFRs disrupt the activity of TH sulfotransferase (SULT) enzymes, thereby altering TH concentrations in the placenta.

In the first aim of this dissertation research, the concentrations of PBDEs and 2,4,6-TBP were measured in a cohort of 102 placenta tissue samples from an ongoing pregnancy cohort in Durham, NC. Methods were developed for the extraction and analysis of the BFR analytes. It was found that 2,4,6-TBP was significantly correlated with all PBDE analytes, indicating that 2,4,6-TBP may share common product applications with PBDEs or that 2,4,6-TBP is a metabolite of PBDE compounds. Additionally, this was the first study to measure 2,4,6-TBP in human placenta tissues.

In the second aim of this dissertation research, the placenta tissue concentrations of THs, as well as the endogenous activity of deiodinase (DI) and TH SULT enzymes were quantified using the same cohort of 102 placenta tissue samples. Enzyme activity was detected in all samples and this was the first study to measure TH DI and SULT activity in human placenta tissues. Enzyme activities and TH concentrations were compared with BFR concentrations measured in Aim 1. There were few statistically significant associations observed for the combined data, however, upon stratifying the data set based on infant sex, additional significant associations were observed. For example, among males, those with the highest concentrations of BDE-99 in placenta had T3 levels 0.80 times those with the lowest concentration of BDE-99 (95% confidence interval (CI): 0.59, 1.07). Whereas females with the highest concentrations of BDE-99 in placenta had T3 levels 1.50 times those with the lowest concentration of BDE-99 (95% CI: 1.10, 2.04). Additionally, all BFR analyte concentrations were higher in the placenta of males versus females and they were significantly higher for 2,4,6-TBP and BDE-209. 3,3’-T2 SULT activity was significantly higher in female placenta tissues, while type 3 DI activity was significantly higher in male placenta tissues. This research is the first to show sex-specific differences in the bioaccumulation of BFRs in human placenta tissue, as well as differences in TH concentrations and endogenous DI and SULT activity. The underlying mechanisms of these observed sex differences warrant further investigation.

In the third aim of this dissertation research, the effects of BFRs were examined in a human choriocarcinoma placenta cell line, BeWo. Michaelis-Menten parameters and inhibition curves were calculated for 2,4,6-TBP, 3-OH BDE-47, and 6-OH BDE-47. 2,4,6-TBP was shown to be the most potent inhibitor of 3,3’-T2 SULT activity with a calculated IC50 value of 11.6 nM. It was also shown that 2,4,6-TBP and 3-OH BDE-47 exhibit mixed inhibition of 3,3’-T2 sulfation in BeWo cell homogenates. Next, a series of cell culture exposure experiments were performed using 1, 6, 12, and 24 hour exposure durations. Once again, 2,4,6-TBP was shown to be the most potent inhibitor of basal 3,3’-T2 SULT activity by significantly decreasing activity at the high and medium dose (1 M and 0.5 M, respectively) at all measured time points. Interestingly, BDE-99 was also shown to inhibit basal 3,3’-T2 SULT activity in BeWo cells following the 24 hour exposure, despite exhibiting no inhibitory effects in the BeWo cell homogenate experiments. This indicates that BDE-99 must act through a pathway other than direct enzyme inhibition. Following exposures, the TH concentrations in the cell culture growth media and mRNA expression of TH-related genes were also examined. There was no observed effect of BFR treatment on these endpoints. Future work should focus on determining the downstream biological effects of TH SULT disruption in placental cells, as well as the underlying mechanisms of action responsible for reductions in basal TH SULT activity following BFR exposure.

This was one of the first studies to measure BFRs in a cohort of placenta tissue samples from the United States and the first study to measure THs, DI activity, and SULT activity in human placenta tissues. This research provides a novel contribution to our growing understanding of the effects of BFRs on TH homeostasis within the human placenta, and provides further evidence for sex-specific differences within this important organ. Future research should continue to investigate the effects of environmental contaminants on TH homeostasis within the placenta, as this represents the most critical and vulnerable stage of human development.

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As the Web evolves unexpectedly fast, information grows explosively. Useful resources become more and more difficult to find because of their dynamic and unstructured characteristics. A vertical search engine is designed and implemented towards a specific domain. Instead of processing the giant volume of miscellaneous information distributed in the Web, a vertical search engine targets at identifying relevant information in specific domains or topics and eventually provides users with up-to-date information, highly focused insights and actionable knowledge representation. As the mobile device gets more popular, the nature of the search is changing. So, acquiring information on a mobile device poses unique requirements on traditional search engines, which will potentially change every feature they used to have. To summarize, users are strongly expecting search engines that can satisfy their individual information needs, adapt their current situation, and present highly personalized search results. In my research, the next generation vertical search engine means to utilize and enrich existing domain information to close the loop of vertical search engine's system that mutually facilitate knowledge discovering, actionable information extraction, and user interests modeling and recommendation. I investigate three problems in which domain taxonomy plays an important role, including taxonomy generation using a vertical search engine, actionable information extraction based on domain taxonomy, and the use of ensemble taxonomy to catch user's interests. As the fundamental theory, ultra-metric, dendrogram, and hierarchical clustering are intensively discussed. Methods on taxonomy generation using my research on hierarchical clustering are developed. The related vertical search engine techniques are practically used in Disaster Management Domain. Especially, three disaster information management systems are developed and represented as real use cases of my research work.

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Eolian dust is a significant source of iron and other nutrients that are essential for the health of marine ecosystems and potentially a controlling factor of the high nutrient-low chlorophyll status of the Subarctic North Pacific. We map the spatial distribution of dust input using three different geochemical tracers of eolian dust, 4He, 232Th and rare earth elements, in combination with grain size distribution data, from a set of core-top sediments covering the entire Subarctic North Pacific. Using the suite of geochemical proxies to fingerprint different lithogenic components, we deconvolve eolian dust input from other lithogenic inputs such as volcanic ash, ice-rafted debris, riverine and hemipelagic input. While the open ocean sites far away from the volcanic arcs are dominantly composed of pure eolian dust, lithogenic components other than eolian dust play a more crucial role along the arcs. In sites dominated by dust, eolian dust input appears to be characterized by a nearly uniform grain size mode at ~4 µm. Applying the 230Th-normalization technique, our proxies yield a consistent pattern of uniform dust fluxes of 1-2 g/m**2/yr across the Subarctic North Pacific. Elevated eolian dust fluxes of 2-4 g/m**2/yr characterize the westernmost region off Japan and the southern Kurile Islands south of 45° N and west of 165° E along the main pathway of the westerly winds. The core-top based dust flux reconstruction is consistent with recent estimates based on dissolved thorium isotope concentrations in seawater from the Subarctic North Pacific. The dust flux pattern compares well with state-of-the-art dust model predictions in the western and central Subarctic North Pacific, but we find that dust fluxes are higher than modeled fluxes by 0.5-1 g/m**2/yr in the northwest, northeast and eastern Subarctic North Pacific. Our results provide an important benchmark for biogeochemical models and a robust approach for downcore studies testing dust-induced iron fertilization of past changes in biological productivity in the Subarctic North Pacific.