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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Development of Bark-based Environmental-friendly Composite Panels

Gupta, Gireesh Kumar 19 January 2010 (has links)
Due to increasing shortage of wood supply and higher environmental concerns with the depletion of forest resources, in recent years, there is a strong interest in using forest and agricultural residues for development of value added products. Bark is a mill-waste residue, available in plenty, having limited uses and causing disposal problems. Bark possesses a large amount of phenolic compounds, which can act as an adhesive in making panels, however only limited research has been done in this area. The main objective of this project is to develop bark-based environment-friendly panels with and without synthetic resins, using mountain pine beetle infested lodgepole pine barks. Analysis of bark constituents, barkboard development, mechanical properties evaluation, characterization and improvement tests were performed. Various results support the possibility of bark utilization for barkboards production; however, more research is required for further improvements and feasible commercial production process.
32

Optimization Techniques for Protein-Protein Co-Regulation and Interaction Prediction

Gremalschi, Stefan 01 December 2009 (has links)
The availability of large gene expression microarray data has brought along many challenges for biological data mining. Many different clustering methods have been proposed and widely used to analyze gene expression data. The underlying concept allows to identify sets of genes sharing similar expression patterns across subsets of samples, and its usefulness has been demonstrated for different organisms and data sets. Currently, there are several biclustering methods that use different techniques; however, it is not clear how to compare the resulted biclusters with respect to biological relevance. So far, there are no available guidelines for choosing a biclustering technique from available ones. In this work, we propose two new Mean Squared Residue (MSR) based biclustering methods. The first method is a dual biclustering algorithm which finds a set of biclusters using a greedy approach. The second method combines dual biclustering algorithm with quadratic programming. The dual biclustering algorithm reduces the size of the matrix, so that the quadratic program can find an optimal bicluster reasonably fast. We also describe the comparison method, explain how we handle bicluster’s overlap and how we treat missing data.
33

Development of Bark-based Environmental-friendly Composite Panels

Gupta, Gireesh Kumar 19 January 2010 (has links)
Due to increasing shortage of wood supply and higher environmental concerns with the depletion of forest resources, in recent years, there is a strong interest in using forest and agricultural residues for development of value added products. Bark is a mill-waste residue, available in plenty, having limited uses and causing disposal problems. Bark possesses a large amount of phenolic compounds, which can act as an adhesive in making panels, however only limited research has been done in this area. The main objective of this project is to develop bark-based environment-friendly panels with and without synthetic resins, using mountain pine beetle infested lodgepole pine barks. Analysis of bark constituents, barkboard development, mechanical properties evaluation, characterization and improvement tests were performed. Various results support the possibility of bark utilization for barkboards production; however, more research is required for further improvements and feasible commercial production process.
34

Low Power Design Using RNS

Classon, Viktor January 2014 (has links)
Power dissipation has become one of the major limiting factors in the design of digital ASICs. Low power dissipation will increase the mobility of the ASIC by reducing the system cost, size and weight. DSP blocks are a major source of power dissipation in modern ASICs. The residue number system (RNS) has, for a long time, been proposed as an alternative to the regular two's complement number system (TCS) in DSP applications to reduce the power dissipation. The basic concept of RNS is to first encode the input data into several smaller independent residues. The computational operations are then performed in parallel and the results are eventually decoded back to the original number system. Due to the inherent parallelism of the residue arithmetics, hardware implementation results in multiple smaller design units. Therefore an RNS design requires low leakage power cells and will result in a lower switching activity. The residue number system has been analyzed by first investigating different implementations of RNS adders and multipliers (which are the basic arithmetic functions in a DSP system) and then deriving an optimal combination of these. The optimum combinations have been used to implement an FIR filter in RNS that has been compared with a TCS FIR filter. By providing different input data and coefficients to both the RNS and TCS FIR filter an evaluation of their respective performance in terms of area, power and operating frequency have been performed. The result is promising for uniform distributed random input data with approximately 15 % reduction of average power with RNS compared to TCS. For a realistic DSP application with normally distributed input data, the power reduction is negligible for practical purposes.
35

Tillage and residue management effects on soil organic matter dynamics in a sandy-loam

Halpern, Moshe T., January 1900 (has links)
Thesis (M.Sc.). / Written for the Dept. of Natural Resource Sciences. Title from title page of PDF (viewed 2009/6/25). Includes bibliographical references.
36

Estudo de rejeitos de galvanoplastia e a sua aplicação na fabricação de peças cerâmicas rústicas para fins decorativos

Delbianco, Gislaine Aparecida Barana [UNESP] 31 October 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-10-31Bitstream added on 2014-06-13T19:02:56Z : No. of bitstreams: 1 delbianco_gab_dr_rcla.pdf: 1713652 bytes, checksum: 5e32e8b54d395b31da88b469da16ea58 (MD5) / O encapsulamento de resíduos em massas cerâmicas tem sido uma solução extremamente interessante porque permite a imobilização de resíduos tóxicos. O objetivo deste trabalho é estudar a aplicação de rejeitos de galvanoplastia às massas cerâmicas, sem o comprometimento das propriedades físico-químicas do produto final, possibilitando assim o desenvolvimento de uma cerâmica rústica, com variação de cores e boas propriedades tecnológicas. Os ensaios de caracterização das matérias primas foram a Fluorescência de Raios X, Iodometria e Difração de Raios X. Corpos de prova foram preparados por via seca, em formulações de massa variando o tipo de argila, a concentração do resíduo e o tipo de processo, foram realizados ensaios para controle das propriedades físico-químicas e para classificação de uso, de acordo com a NBR 13818/97. A análise petrográfica permitiu observar o comportamento do resíduo nos diferentes processos de preparação e os ensaios de eflorescência, lixiviação e solubilização comprovaram a inertização do resíduo. A utilização dos resíduos como aditivo apresentaram resultados bastante satisfatórios e indicam a viabilidade comercial da cerâmica rústica, pois a presença de CuO e NiO possibilitaram o aumento da vitrificação das massas cerâmicas e permitiu utilizar a argila considerada “rejeito” pelos ceramistas do Pólo de Santa Gertrudes-SP. / The encapsulating of residues in ceramic masses has been an extremely interesting solution because it allows the immobilization of toxic residues. The objective of this paper is to study the application of wastes of galvanoplasty to the ceramic masses, without compromising the physicist-chemistries properties of the final product, thus making possible the development of rustic ceramics, with variation of colors and good technological properties. The assays of characterization of the raw materials were the X Rays Fluorescence, Iodometry and X Ray Diffraction. Samples were prepared by dry process method, in mass formularizations varying the type of clay, the concentration of the residue and the type of process, assays were carried out to know the control of physicist-chemistries properties and classification of use, according to NBR 13818/97. The petrographic analysis allowed to observe the behavior of the residue in different processes of preparation and the assays of efflorescence, leaching and solubilization had proven the inertness of the residue. The use of the residues as additive presented sufficiently satisfactory results and indicates the commercial viability of rustic ceramics; therefore the presence of CuO and NiO makes possible the increase of the vitrification of the ceramic masses and allowed to use the considered clay “waste” for the ceramists of the pole of Santa Gertrudes-SP.
37

DETECÇÃO DE RESÍDUOS DE DISPARO DE ARMA DE FOGO EM LARVAS CADAVÉRICAS POR ICP OES

MOTTA, L. C. 28 March 2018 (has links)
Made available in DSpace on 2018-08-01T21:58:49Z (GMT). No. of bitstreams: 1 tese_12216_Larissa Campos Motta.pdf: 5830957 bytes, checksum: bad711c20153d4ed1e56fd1b91ea34b7 (MD5) Previous issue date: 2018-03-28 / Considerando o grande aumento das mortes violentas, principalmente no Brasil, e a crescente utilização de armas de fogo para cometer tais crimes, a balística forense associada a entomologia forense se tornam grandes aliadas nas investigações criminais. As concentrações de chumbo (Pb), bário (Ba) e antimônio (Sb), caracerísticos de resíduos de disparo de arma de fogo (GSR GunShot Residue), foram monitoradas em larvas de moscas (imaturos de Chrysomya albiceps). As coletas sucederam em um cadáver de porco, do sexo feminino, morto com três disparos realizados com pistola Taurus®, calibre .40 a curta distância (entre 25 e 40 cm), sendo dois disparos na região cefálica e um na região abdominal, em um período de 2 a 12 dias após a morte, durante o inverno, sob a influência da chuva e alta umidade relativa do ar. Dessa forma, o objetivo deste trabalho foi avaliar a aplicabilidade da técnica de espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) para a quantificação de Pb, Ba e Sb proveniente de GSR em larvas cadavéricas num ambiente não controlado, simulando um caso real de homicidio. Foi possível detectar e quantificar os três elementos traço de interesse pela técnica proposta, onde as concentrações mantiveram-se praticamente constante durante o estágio de putrefação. Concentrações mínimas (Pb = 382,26 μg·L-1; Ba = 140,50 μg·L-1; Sb = 39,18 μg·L-1) e as concentrações máximas (Pb = 522,66 μg·L-1; Ba = 190,30 μg·L-1; Sb = 56,14 μg·L-1) foram encontradas durante o terceiro e quinto dia post mortem, respectivamente. As amostras também foram analisadas pelo teste colorimétrico usando rodizonato de sódio (reação Feigl-Suter) apresentando resultado negativo para todas as soluções obtidas a partir dos imaturos de Chrysomya albiceps. Uma hipótese para a constância nas concentrações dos três elementos, é que de acordo com a literatura, as larvas da espécie Chrysomya albiceps podem exercer papel como predadora intraguilda de larvas de outras espécies de Dípteras, além de realizar canibalismo. Sendo assim, a técnica de ICP OES apresenta maior sensibilidade na quantificação frente ao convencional teste colorimétrico, mostrando ser uma técnica aplicável a esse tipo de matriz. É importante notar que o desenvolvimento tal pesquisa é de grande importância forense e é uma técnica que apresenta potencial para aplicação futura em casos de morte violenta, em que a vítima se encontra em decomposição inicial, moderada e avançada. Nesse aspecto, o desenvolvimento e aperfeiçoamento de metodologias eficientes são de grande relevância para a elucidação de crimes.
38

Strip-Tillage Production Systems for Tobacco

Jerrell, Scottie Lee 25 May 2001 (has links)
Conservation tillage production systems for flue-cured tobacco (Nicotiana tabacum L.) have been studied for many years. Inadequate chemical weed control and lack of acceptable pesticide and fertilizer application resulted in consistently lower yields and inferior cured leaf quality. The development of new conservation tillage equipment, improved methods of fertilizer application, and new herbicides, have resulted in a renewed interest in conservation tillage labeled for tobacco. This research investigated management practices to address slow early season growth characteristic of strip-tillage tobacco production. Objectives of the first study were to evaluate the methods of starter fertilizer application and determine the optimal rate. A transplant water treatment (11 kg ha⁻¹) and 3 rates (11, 22, and 45 kg ha⁻¹) of injected 9-45-15 (N:P₂O₅:K₂O) water soluble starter fertilizer were evaluated for early season plant growth and time of topping. Starter fertilizer treatments increased tobacco root weight by 22% and leaf area up to 41%. Earlier topping was observed as a result of starter fertilizer with 23 and 6% more plants topped during the initial topping date in 1999 and 2000, respectively. Starter fertilizer did not consistently increase the yield of either strip-tillage or conventional tillage tobacco. The objectives of the second study were to compare the use of raised beds with flat-planting and investigate cover crop residue management techniques. Residue management treatments minimized residue within the strip-tilled area with an early hooded spray application (strip-killed) of a burndown herbicide as opposed to the traditional broadcast burndown application. The use of raised beds for strip-tillage production of tobacco showed no clear benefit when compared to flat-planting. Strip-tillage plots were similar to conventional tillage for cured leaf quality and yield. Early season strip-kill burndown herbicide applications proved beneficial in reducing difficulties incorporating residue into the strip-tilled area thus improving the quality of the prepared seed bed. This research has added to the present knowledge regarding strip-tillage tobacco production, and refined necessary cultural practices. Transplant starter fertilizer is recommended to overcome the typical slow early season growth characteristic of strip-tilled tobacco. However, increased rates (greater than 11 kg ha⁻¹) or under-row injection of the material had no added benefit. The research also demonstrated that the use of raised beds should not be considered a necessary practice with the use of a strip-till implement that incorporates under-row subsoil tillage. This research has demonstrated that tobacco yields and quality comparable to conventional tillage can be realized using strip-tillage production techniques. / Master of Science
39

Ultra-Wideband Antenna Characterization and Modeling

Licul, Stanislav 17 November 2004 (has links)
A new methodology is presented for characterizing an antenna system both in the time and frequency domain with one set of parameters using a singularity expansion method representation. A minimal set of parameter modeling antenna systems using the Matrix-Pencil method has been demonstrated. It has been shown that it is possible to obtain frequency-domain patterns from pole/residue models of antenna realized effective length. Thus, a pole/residue model of the antenna realized effective length presents a complete description in both the time and frequency domains. Once such a model is available, one can obtain the antenna pattern, directivity and gain in the frequency domain and the radiated transient waveform for an arbitrary excitation waveform and an arbitrary antenna orientation. / Ph. D.
40

Crop residue management and its impacts on soil properties

He, Yuxin January 1900 (has links)
Doctor of Philosophy / Agronomy / DeAnn R. Presley / Crop residue removal for livestock feeding and biofuel production at large scales must be evaluated to assess impacts on soil productivity and properties. Among all the potential negative impacts, wind erosion is a major concern in the central Great Plains. We conducted an on-farm study from 2011 to 2013 by removing crop residue at five levels (0, 25, 50, 75, and 100%) to determine the effects of crop residue removal on soil wind erosion parameters such as dry aggregate size distribution including soil wind erodible fraction (EF <0.84 mm aggregates), geometric mean diameter (GMD) and geometric standard deviation (GSD), dry aggregate stability, and soil surface roughness. The sub-model of Wind Erosion Prediction System (WEPS) developed by the USDA-ARS, Single-event Wind Erosion Evaluation Program (SWEEP) is a stand-alone companion software package that can be applied to simulate soil loss and dust emission from a single windstorm event. We applied measured data (i.e. EF, GMD, GSD, and roughness) to SWEEP for predicting wind velocity that can initiate wind erosion and soil loss under each crop residue removal condition with wind velocity at 13 m sˉ¹. The threshold wind velocity to initiate wind erosion generally decreased with increase in crop residue removal levels, particularly for residue removal >75%. The total amount of soil loss in 3 hours ranged from about 0.2 to 2.5 kg mˉ² and depends on soil condition and crop residue cover. On the other hand, high-yielding crops can produce abundant crop residue, which then raises the question that if a farmer wants to reduce residue, what could they do without removing it? The application of fertilizer on crop residue to stimulate microbial activity and subsequent decomposition of the residue is often debated. We conducted wheat straw decomposition field experiments under different fertilizer rates and combinations at three locations in western Kansas following wheat harvest in 2011 and 2012. A double shear box apparatus instrumented with a load cell measured the shear stress required to cut wheat straw and photomicrography was used to measure the cross-sectional area of wheat straw after shearing. Total C and N were also analyzed. The fertilizer rate and timing of application during summer 2012 and Fall 2013 at the Hays site had impacts on wheat straw shear stress at break point. Across site years, earlier (fall) fertilizer application generally resulted in lower remaining aboveground biomass as compared to a spring application. Multivariate and linear regressions suggested that N and C:N ratio partially explain the results observed with respect to treatment effects on winter wheat residue decomposition.

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