977 resultados para Alternative schooling options
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Fifty Bursa of Fabricius (BF) were examined by conventional optical microscopy and digital images were acquired and processed using Matlab® 6.5 software. The Artificial Neuronal Network (ANN) was generated using Neuroshell® Classifier software and the optical and digital data were compared. The ANN was able to make a comparable classification of digital and optical scores. The use of ANN was able to classify correctly the majority of the follicles, reaching sensibility and specificity of 89% and 96%, respectively. When the follicles were scored and grouped in a binary fashion the sensibility increased to 90% and obtained the maximum value for the specificity of 92%. These results demonstrate that the use of digital image analysis and ANN is a useful tool for the pathological classification of the BF lymphoid depletion. In addition it provides objective results that allow measuring the dimension of the error in the diagnosis and classification therefore making comparison between databases feasible.
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It is well known that the numerical solutions of incompressible viscous flows are of great importance in Fluid Dynamics. The graphics output capabilities of their computational codes have revolutionized the communication of ideas to the non-specialist public. In general those codes include, in their hydrodynamic features, the visualization of flow streamlines - essentially a form of contour plot showing the line patterns of the flow - and the magnitudes and orientations of their velocity vectors. However, the standard finite element formulation to compute streamlines suffers from the disadvantage of requiring the determination of boundary integrals, leading to cumbersome implementations at the construction of the finite element code. In this article, we introduce an efficient way - via an alternative variational formulation - to determine the streamlines for fluid flows, which does not need the computation of contour integrals. In order to illustrate the good performance of the alternative formulation proposed, we capture the streamlines of three viscous models: Stokes, Navier-Stokes and Viscoelastic flows.
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At present, permanent magnet synchronous generators (PMSGs) are of great interest. Since they do not have electrical excitation losses, the highly efficient, lightweight and compact PMSGs equipped with damper windings work perfectly when connected to a network. However, in island operation, the generator (or parallel generators) alone is responsible for the building up of the network and maintaining its voltage and reactive power level. Thus, in island operation, a PMSG faces very tight constraints, which are difficult to meet, because the flux produced by the permanent magnets (PMs) is constant and the voltage of the generator cannot be controlled. Traditional electrically excited synchronous generators (EESGs) can easily meet these constraints, because the field winding current is controllable. The main drawback of the conventional EESG is the relatively high excitation loss. This doctoral thesis presents a study of an alternative solution termed as a hybrid excitation synchronous generator (HESG). HESGs are a special class of electrical machines, where the total rotor current linkage is produced by the simultaneous action of two different excitation sources: the electrical and permanent magnet (PM) excitation. An overview of the existing HESGs is given. Several HESGs are introduced and compared with the conventional EESG from technical and economic points of view. In the study, the armature-reaction-compensated permanent magnet synchronous generator with alternated current linkages (ARC-PMSG with ACL) showed a better performance than the other options. Therefore, this machine type is studied in more detail. An electromagnetic design and a thermal analysis are presented. To verify the operation principle and the electromagnetic design, a down-sized prototype of 69 kVA apparent power was built. The experimental results are demonstrated and compared with the predicted ones. A prerequisite for an ARC-PMSG with ACL is an even number of pole pairs (p = 2, 4, 6, …) in the machine. Naturally, the HESG technology is not limited to even-pole-pair machines. However, the analysis of machines with p = 3, 5, 7, … becomes more complicated, especially if analytical tools are used, and is outside the scope of this thesis. The contribution of this study is to propose a solution where an ARC-PMSG replaces an EESG in electrical power generation while meeting all the requirements set for generators given for instance by ship classification societies, particularly as regards island operation. The maximum power level when applying the technology studied here is mainly limited by the economy of the machine. The larger the machine is, the smaller is the efficiency benefit. However, it seems that machines up to ten megawatts of power could benefit from the technology. However, in low-power applications, for instance in the 500 kW range, the efficiency increase can be significant.
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Kandidaatintyön teoriaosassa perehdytään mikroreaktoreihin sekä niiden etuihin ja haasteisiin. Lisäksi esitellään lyhyesti, kuinka sekoitus näissä reaktoreissa voidaan järjestää erilaisten sekoituselementtien avulla sekä uusien ainetta lisäävien valmistusmenetelmien tarjoamat mahdollisuudet reaktorien valmistukselle. Mikroreaktorien edut liittyvät pääasiassa prosessin helpompaan hallittavuuteen, mikä johtaa mm. turvallisuuden lisääntymiseen ja energiasäästöihin. Lisäksi esitellään kokeellisessa osassa lähtöaineina käytettävät vetyperoksidi ja muurahaishappo, sekä tuotteena syntyvä permuurahaishappo ja sen käyttökohteita. Permuurahaishappoa käytetään mm. desinfiointiaineiden yhtenä komponenttina. Sitä voidaan käyttää myös paperikoneen vesikierron bakteerien tappamiseen. Epästabiiliutensa vuoksi permuurahaishappo voi räjähtää jopa huoneenlämmössä, mikä aiheuttaa merkittävän riskin sen varastoinnille ja kuljetukselle. Tästä syystä työssä tutkittu menetelmä permuurahaishapon valmistamiseksi mikroreaktorissa tarjoaa hyvän vaihtoehdon permuurahaishapon tuottamiseksi suoraan tarpeeseen. Kokeellisessa osassa permuurahaishappoa valmistettiin muurahaishaposta ja vetyperoksidista käyttäen rikkihappoa katalyyttinä reaktion nopeuttamiseksi. Lämpötilan ja viipymäajan vaikutusta tutkittiin permuurahaishapon muodostumiseen. Molempien nosto vaikutti edullisesti permuurahaishapon saantoon, mutta lämpötilan nosto lisää samalla räjähdysriskiä. Mikroreaktorissa lämpötilan nosto on kuitenkin suhteessa turvallisempaa makroreaktoriin verrattuna.
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An ERP system investment analysis method using a Fuzzy Pay-Off approach for Real Option valuation is examined. It is studied, how the investment can be incrementally adopted and analyzed as a compounding Real Option model. The modeling allows follow-up. IS system development model COCOMO is presented as an example for investment analysis. The thesis presents the usage of Real Options as an alternative for the valuation of an investment. An idea is presented to use a continuous investment follow-up during the investment. This analysis can be performed using Real Options. As a tool for the analysis, the Fuzzy Pay-Off method is presented as an alternative for investment valuation.
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The resistance of barnyardgrass (Echinochloa crus-galli) to imidazolinone herbicides is a worldwide problem in paddy fields. A rapid diagnosis is required for the selection of adequate prevention and control practices. The objectives of this study were to develop expedite bioassays to identify the resistance to imidazolinone herbicides in barnyardgrass and to evaluate the efficacy of alternative herbicides for the post-emergence control of resistant biotypes. Three experiments were conducted to develop methods for diagnosis of resistance to imazethapyr and imazapyr + imazapic in barnyardgrass at the seed, seedling and tiller stages, and to carry out a pot experiment to determine the efficacy of six herbicides applied at post-emergence in 13 biotypes of barnyardgrass resistant to imidazolinones. The seed soaking bioassay was not able to differentiate the resistant and susceptible biotypes. The resistance of barnyardgrass to imidazolinones was effectively discriminated in the seedlings and tiller bioassays seven days after incubation at the concentrations of 0.001 and 0.0001 mM, respectively, for both imazethapyr and imazapyr + imazapic. The biotypes identified as resistant to imidazolinones showed different patterns of susceptibility to penoxsulam, bispyribac-sodium and pyrazosulfuron-ethyl, and were all controlled with profoxydim and cyhalofop-butyl. The seedling and tiller bioassays are effective in the diagnosis of barnyardgrass resistance to imidazolinone herbicides, providing an on-season opportunity to identify the need to use alternative herbicides to be applied at post-emergence for the control of the resistant biotypes.
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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The repetitive use of iodosulfuron for the control of weeds in winter cereals in the south of Brazil has favored the emergence of resistant Raphanus sativus biotypes. The objective of this study was to evaluate: the response of Raphanus sativus biotypes susceptible and resistant to different dosages of iodosulfuron; the control of biotypes with alternative registered herbicides for the control of the species in crops of wheat, corn and soybean; and the existence of cross-resistance of the biotypes. Thus, four experiments were done in a greenhouse, with a completely randomized design and four replicates. The experimental units were composed of vases with a volumetric capacity of 0.75 L filled with substrate, containing a plant each. For the dose-response curve, three biotypes (factor A) and nine doses of the iodosulfuron herbicide (factor B) were used. For the alternative control, the recommendation was herbicides in pre or postemergence of the crops, and the crossed-resistance was evaluated by using herbicides that inhibit the ALS enzyme of different chemical groups. The analyzed variables were control and shoot dry matter. GR50 of the susceptible biotype (B1) was 0.11 g a.i. ha-1, whereas GR50 of resistant biotypes (B4 and B13) was 102.9 and 86.8 g a.i. ha-1 of the iodosulfuron herbicide, respectively. The resistant biotypes presented crossed resistance to herbicides that inhibit the ALS enzyme, where the control can be efficient with the use of herbicides with different action mechanisms.
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Six common bean cultivars were crossed in diallel and the segregant populations were assessed in the F2 and F3 generations to compare methodologies for parental selection in a breeding program based on hybridization. The cultivars involved in the diallel were A 114, A 77, ESAL 686, Milionário, Carioca, and Flor de Mayo. The segregant F2 and F3 generations were assessed on the experimental campus of the Universidade Federal de Larvas, in July 1994. It was found that the cultivars differed in their general combining ability (GCA). Flor de Mayo, which belongs to the Durango race, had the largest positive GCA estimate for grain field, and the cultivars from the Mesoamerican race, Milionário and A 114, the smallest GCA estimates. For flowering, the cultivar that most contributed to reduced plant cycle was ESAL 686. There was agreement among the results obtained from the diallel and the estimates of the parameter m + a of the populations. However, it was evident that the estimate of genetic variance of the populations should be considered as a condition to identify the hybrid population that will produce a line with high performance.
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Plants and some other organisms including protists possess a complex branched respiratory network in their mitochondria. Some pathways of this network are not energy-conserving and allow sites of energy conservation to be bypassed, leading to a decrease of the energy yield in the cells. It is a challenge to understand the regulation of the partitioning of electrons between the various energy-dissipating and -conserving pathways. This review is focused on the oxidase side of the respiratory chain that presents a cyanide-resistant energy-dissipating alternative oxidase (AOX) besides the cytochrome pathway. The known structural properties of AOX are described including transmembrane topology, dimerization, and active sites. Regulation of the alternative oxidase activity is presented in detail because of its complexity. The alternative oxidase activity is dependent on substrate availability: total ubiquinone concentration and its redox state in the membrane and O2 concentration in the cell. The alternative oxidase activity can be long-term regulated (gene expression) or short-term (post-translational modification, allosteric activation) regulated. Electron distribution (partitioning) between the alternative and cytochrome pathways during steady-state respiration is a crucial measurement to quantitatively analyze the effects of the various levels of regulation of the alternative oxidase. Three approaches are described with their specific domain of application and limitations: kinetic approach, oxygen isotope differential discrimination, and ADP/O method (thermokinetic approach). Lastly, the role of the alternative oxidase in non-thermogenic tissues is discussed in relation to the energy metabolism balance of the cell (supply in reducing equivalents/demand in energy and carbon) and with harmful reactive oxygen species formation.
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The conventional activated sludge processes (CAS) for the treatment of municipal wastewater are going to be outdated gradually due to more stringent environmental protection laws and regulations. The Membrane bioreactors (MBRs) are the most promising modern technology widely accepted in the world of wastewater treatment due to their highly pronounced features such as high quality effluent, less foot print and working under high MLSS concentration. This research project was carried out to investigate the feasibility and effectiveness of MBR technology compare to the CAS process based on the scientific facts and results. The pilot scale MBR pilot plant was run for more than 150 days and the analysis results were evaluated. The prime focus of the project was to evaluate the correlation of permeate flux under different operating MLSS concentrations. The permeate flux was found almost constant regardless of variations in MLSS concentrations. The removal of micropollutant such as heavy metals, PCPPs, PFCs, steroidal hormones was also studied. The micropollutant removal performance of MBR process was found relatively effective than CAS process. Furthermore, the compatibility of submerged membranes within the bioreactor had truly reduced the process footprint.
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Galectin-1 belongs to an evolutionarily conserved family of animal ß-galactoside-binding proteins, which exert their functions by crosslinking the oligosaccharides of specific glycoconjugate ligands. During the past decade, attempts to identify the functional role of galectin-1 suggested participation in the regulation of the immune response. Only in the last few years has the molecular mechanism involved in these properties been clearly elucidated, revealing a critical role for galectin-1 as an alternative signal in the generation of T cell death. In the present study we will discuss the latest advances in galectin research in the context of the regulation of the immune response, not only at the central level but also at the periphery. Moreover, we will review the purification, biochemical properties and functional significance of a novel galectin-1-like protein from activated rat macrophages, whose expression is differentially regulated according to the activation state of the cells. The novel role of a carbohydrate-binding protein in the regulation of apoptosis is providing a breakthrough in galectin research and extending the interface between immunology, glycobiology and clinical medicine.
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It is well known that mitochondria are the main site for ATP generation within most tissues. However, mitochondria also participate in a surprising number of alternative activities, including intracellular Ca2+ regulation, thermogenesis and the control of apoptosis. In addition, mitochondria are the main cellular generators of reactive oxygen species, and may trigger necrotic cell death under conditions of oxidative stress. This review concentrates on these alternative mitochondrial functions, and their role in cell physiopathology.