968 resultados para Order of Convergence
Resumo:
In order to understand the behavior of pretilachlor, a popular rice herbicide in the world, and a synergetic active ingredient, dimethametryn, a monitoring study was conducted in 3 paddy plots in Kyushu region, Japan. The monitoring indicated different behaviors for both pesticides from those reported in the literature. Maximum concentrations of pretilachlor and dimethametryn were 1 order of magnitude lower than the values observed in previous studies. However, the dissipation rates estimated from monitoring data were in agreement with other studies in Japan. The pesticide product was tested and showed good dissolution of pretilachlor and dimethametryn in water, suggesting that another study is needed to explain the low concentrations of the two pesticides in the fields. Besides pesticide behaviors, it was observed from the monitoring that water management in paddy rice cultivation still requires more attention to reduce the environmental risk of rice pesticides.
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The floating-zone method with different growth ambiences has been used to selectively obtain hexagonal or orthorhombic DyMnO3 single crystals. The crystals were characterized by x-ray powder diffraction of ground specimens and a structure refinement as well as electron diffraction. We report magnetic susceptibility, magnetization and specific heat studies of this multiferroic compound in both the hexagonal and the orthorhombic structure. The hexagonal DyMnO3 shows magnetic ordering of Mn3+ (S = 2) spins on a triangular Mn lattice at T-N(Mn) = 57 K characterized by a cusp in the specific heat. This transition is not apparent in the magnetic susceptibility due to the frustration on the Mn triangular lattice and the dominating paramagnetic susceptibility of the Dy3+ (S = 9/2) spins. At T-N(Dy) = 3 K, a partial antiferromagnetic order of Dy moments has been observed. In comparison, the magnetic data for orthorhombic DyMnO3 display three transitions. The data broadly agree with results from earlier neutron diffraction experiments, which allows for the following assignment: a transition from an incommensurate antiferromagnetic ordering of Mn3+ spins at T-N(Mn) = 39 K, a lock-in transition at Tlock-in = 16 K and a second antiferromagnetic transition at T-N(Dy) = 5 K due to the ordering of Dy moments. Both the hexagonal and the orthorhombic crystals show magnetic anisotropy and complex magnetic properties due to 4f-4f and 4f-3d couplings.
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Experiments in spintronics necessarily involve the detection of spin polarization. The sensitivity of this detection becomes an important factor to consider when extending the low temperature studies on semiconductor spintronic devices to room temperature, where the spin signal is weaker. In pump-probe experiments, which optically inject and detect spins, the sensitivity is often improved by using a photoelastic modulator (PEM) for lock-in detection. However, spurious signals can arise if diode lasers are used as optical sources in such experiments, along with a PEM. In this work, we eliminated the spurious electromagnetic coupling of the PEM onto the probe diode laser, by the double modulation technique. We also developed a test for spurious modulated interference in the pump-probe signal, due to the PEM. Besides, an order of magnitude enhancement in the sensitivity of detection of spin polarization by Kerr rotation, to 3x10(-8) rad was obtained by using the concept of Allan variance to optimally average the time series data over a period of 416 s. With these improvements, we are able to experimentally demonstrate at room temperature, photoinduced steady-state spin polarization in bulk GaAs. Thus, the advances reported here facilitate the use of diode lasers with a PEM for sensitive pump-probe experiments. They also constitute a step toward detection of spin-injection in Si at room temperature.
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This paper empirically examines the effect of current tax policy on home ownership, specifically looking at how developer contributions impact house prices. Developer contributions are a commonly used mechanism for local governments to pay for new urban infrastructure. This research applies a hedonic house price model to 4,699 new and 25,053 existing house sales in Brisbane from 2005 to 2011. The findings of is research are consistent with international studies that support the proposition that developer contributions are over passed. This study has provided evidence that suggest developer contributions are over passed to both new and existing homes in the order of around 400%. These findings suggest that developer contributions are thus a significant contributor to increasing house prices, reduced housing supply and are thus an inefficient and inequitable tax. By testing this effect on both new and existing homes, this research provides evidence in support of the proposition that not only are developer contributions over passed to new home buyers but also to buyers of existing homes. Thus the price inflationary effect of these developer contributions are being felt by all home buyers across the community, resulting in increased mortgage repayments of close to $1,000 per month in Australia. This is the first study to empirically examine the impact of developer contributions on house prices in Australia. These results are important as they inform governments on the outcomes of current tax policy on home ownership, providing the first evidence of its kind in Australia. This is an important contribution to the tax reform agenda in Australia.
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The catalytic effects of Fe2O3, Ni2O3, MnO2, and Co2O3 transition metal oxides (TMO) on the combustion of polystyrene and carboxyl-terminated polybutadiene were investigated. The order of activity of TMO's was explained by the presence of Co and absence of Fe and Ni in their lattice systems along with a reduced electron-transfer process; in systems which induce the metal ions to enter the lattice, the electron transfer process is much greater. The thermal decomposition of ammonium perchlorate propellants was enhanced to a greater extent by Co2O3 and MnO2 than by Fe2O3 and Ni2O3.
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This dissertation studies the language of Latin letters that were written in Egypt and Vindolanda (in northern Britain) during the period 1st century BC 3rd century AD on papyri, ostraca, and wooden tablets. The majority of the texts is, in one way or another, connected with the Roman army. The focus of the study is on syntax and pragmatics. Besides traditional philological methods, modern syntactic theory is used as well, especially in the pragmatic analysis. The study begins with a critical survey of certain concepts that are current in the research on the Latin language, most importantly the concept of vulgar Latin , which, it is argued, seems to be used as an abstract noun for variation and change in Latin . Further, it is necessary to treat even the non-literary material primarily as written texts and not as straightforward reflections of spoken language. An examination of letter phraseology shows that there is considerable variation between the two major geographical areas of provenance. Latin letter writing in Egypt was influenced by Greek. The study highlights the importance of seeing the letters as a text type, with recurring phraseological elements appearing in the body text as well. It is argued that recognising these elements is essential for the correct analysis of the syntax. Three areas of syntax are discussed in detail: sentence connection (mainly parataxis), syntactically incoherent structures and word order (the order of the object and the verb). For certain types of sentence connection we may plausibly posit an origin in spoken Latin, but for many other linguistic phenomena attested in this material the issue of spoken Latin is anything but simple. Concerning the study of historical syntax, the letters offer information about the changing status of the accusative case. Incoherent structures may reflect contaminations in spoken language but usually the reason for them is the inability of the writer to put his thoughts into writing, especially when there is something more complicated to be expressed. Many incoherent expressions reflect the need to start the predication with a thematic constituent. Latin word order is seen as resulting from an interaction of syntactic and pragmatic factors. The preference for an order where the topic is placed sentence-initially can be seen in word order more generally as well. Furthermore, there appears a difference between Egypt and Vindolanda. The letters from Vindolanda show the order O(bject) V(erb) clearly more often than the letters from Egypt. Interestingly, this difference correlates with another, namely the use of the anaphoric pronoun is. This is an interesting observation in view of the fact that both of these are traditional Latin features, as opposed to those that foreshadow the Romance development (VO order and use of the anaphoric ille). However, it is difficult to say whether this is an indication of social or regional variation.
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Error estimates for the error reproducing kernel method (ERKM) are provided. The ERKM is a mesh-free functional approximation scheme [A. Shaw, D. Roy, A NURBS-based error reproducing kernel method with applications in solid mechanics, Computational Mechanics (2006), to appear (available online)], wherein a targeted function and its derivatives are first approximated via non-uniform rational B-splines (NURBS) basis function. Errors in the NURBS approximation are then reproduced via a family of non-NURBS basis functions, constructed using a polynomial reproduction condition, and added to the NURBS approximation of the function obtained in the first step. In addition to the derivation of error estimates, convergence studies are undertaken for a couple of test boundary value problems with known exact solutions. The ERKM is next applied to a one-dimensional Burgers equation where, time evolution leads to a breakdown of the continuous solution and the appearance of a shock. Many available mesh-free schemes appear to be unable to capture this shock without numerical instability. However, given that any desired order of continuity is achievable through NURBS approximations, the ERKM can even accurately approximate functions with discontinuous derivatives. Moreover, due to the variation diminishing property of NURBS, it has advantages in representing sharp changes in gradients. This paper is focused on demonstrating this ability of ERKM via some numerical examples. Comparisons of some of the results with those via the standard form of the reproducing kernel particle method (RKPM) demonstrate the relative numerical advantages and accuracy of the ERKM.
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Recent decreases in costs, and improvements in performance, of silicon array detectors open a range of potential applications of relevance to plant physiologists, associated with spectral analysis in the visible and short-wave near infra-red (far-red) spectrum. The performance characteristics of three commercially available ‘miniature’ spectrometers based on silicon array detectors operating in the 650–1050-nm spectral region (MMS1 from Zeiss, S2000 from Ocean Optics, and FICS from Oriel, operated with a Larry detector) were compared with respect to the application of non-invasive prediction of sugar content of fruit using near infra-red spectroscopy (NIRS). The FICS–Larry gave the best wavelength resolution; however, the narrow slit and small pixel size of the charge-coupled device detector resulted in a very low sensitivity, and this instrumentation was not considered further. Wavelength resolution was poor with the MMS1 relative to the S2000 (e.g. full width at half maximum of the 912 nm Hg peak, 13 and 2 nm for the MMS1 and S2000, respectively), but the large pixel height of the array used in the MMS1 gave it sensitivity comparable to the S2000. The signal-to-signal standard error ratio of spectra was greater by an order of magnitude with the MMS1, relative to the S2000, at both near saturation and low light levels. Calibrations were developed using reflectance spectra of filter paper soaked in range of concentrations (0–20% w/v) of sucrose, using a modified partial least squares procedure. Calibrations developed with the MMS1 were superior to those developed using the S2000 (e.g. coefficient of correlation of 0.90 and 0.62, and standard error of cross-validation of 1.9 and 5.4%, respectively), indicating the importance of high signal to noise ratio over wavelength resolution to calibration accuracy. The design of a bench top assembly using the MMS1 for the non-invasive assessment of mesocarp sugar content of (intact) melon fruit is reported in terms of light source and angle between detector and light source, and optimisation of math treatment (derivative condition and smoothing function).
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Laser surface cladding was carried out on a creep-resistant MRI 153M magnesium alloy with a mixture of Al and Al2O3 powders using a pulsed Nd:YAG laser at scan speeds of 21, 42, 63 and 84 mm/s. The Al2O3 particles partially or completely melted during laser irradiation and re-solidified with irregular shapes in the size range of 5–60 µm along with a few islands as large as 500 µm, within the grain-refined Mg-rich dendritic matrix. More than an order of magnitude improvement in wear resistance after cladding was attributed to the presence of ultra-hard Al2O3 particles, increased solid solubility of Al and other alloying elements, and a very fine dendritic microstructure as a result of rapid solidification in the cladded layer. However, corrosion resistance of the laser cladded alloy was reduced by almost an order of magnitude compared to that of the as-cast alloy mainly due to the presence of cracks and pores in the cladded layer.
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Molecular dynamics (MD) simulations are reported for an anchored bilayer formed by the intercalation of cetyl trimethyl ammonium (CTA) and CH3(CH2)15N+(CH3) ions in a layered solid, CdPS3. The intercalated CTA ions are organized with the cationic headgroups tethered to the inorganic sheet and the hydrocarbon tails arranged as bilayers. Simulations were performed at three temperatures, 65, 180, and 298 K, using an isothermal−isobaric ensemble that was subsequently switched once macroscopic parameters had converged to a canonical isothermal−isochoric ensemble. The simulations are able to reproduce the experimental features of this system, including the formation of the bilayer and layer-to-layer separation distance. An analysis of the conformation of the chains showed that at all three temperatures a fraction of the alkyl chains retained a planar all-trans conformation, and that gauche bonds occurred as part of a “kink” (gauche+−trans−gauche−) sequence and not as isolated gauche bonds. Trans−gauche isomerization rates for the alkyl chains in the anchored bilayer are slower than those in lipid bilayers at the same temperature and show a progressive increase as the torsion numbers approach the tail. A two-dimensional periodic Voronoi tessellation analysis was performed to obtain the single-molecular area of an alkyl chain in the bilayer. The single-molecular area relaxation times are an order of magnitude longer than the trans−gauche isomerization times. The results indicate that the trans−gauche isomerization is associated with the creation and annihilation of a kink defect sequence. The results of the present MD simulation explain the apparent conflicting estimates of the gauche disorder in this system as obtained from infrared and 13C nuclear magnetic resonance measurements.
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Analogue and digital techniques for linearization of non-linear input-output relationship of transducers are briefly reviewed. The condition required for linearizing a non-linear function y = f(x) using a non-linear analogue-to-digital converter, is explained. A simple technique to construct a non-linear digital-to-analogue converter, based on ' segments of equal digital interval ' is described. The technique was used to build an N-DAC which can be employed in a successive approximation or counter-ramp type ADC to linearize the non-linear transfer function of a thermistor-resistor combination. The possibility of achieving an order of magnitude higher accuracy in the measurement of temperature is shown.
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The interactions of metallo derivatives of macrocyclic tetrapyrrole pigments, pheophytin a (pheo), phthalocyanin (phth), and tetraphenylporphyrin (TPP) with sym-trinitrobenzene (TNB) have been studied with use of spectroscopic methods. These macrocyles form 1:l molecular complexw with the acceptor. The association constants (K) for the interactions follow the decreasing order of binding as pheo > phth > TPP. The divalent metal ions influence the values of K for the various metallo TPP derivatives, and the relative order of stabilities decrease as Co > Cu = VO > Ni > Zn. The stereochemistry of M(TPP) and the electronic configuration of the metal ions are shown to contribute to the magnitudes of K. The acceptor strongly quenches the fluorescence of the metallo macrocycles, and the quenching constant decreases as pheo > phth > TPP. The formation of exciplexes is postulated on the basis of the rate of bimolecular quenching constants and solvent effects.
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The study approaches two modern novels using the conceptual frame of Lacanian psychoanalysis, especially the Lacanian notion of subject. The novels can be described as subversive “Bildungsromans” (development novels) highly influenced by psychoanalytic thought. Anaïs Nin’s (1903—1977) “poetic novel” House of Incest (1936) is a story of sexual and artistic awakening while Hélène Cixous’s (b. 1937) first novel Dedans (1969) depicts the growth of a little girl whose father dies. Both are first novels and first person narratives. Concentrating in the narrator’s internal life the novels writings break with the realistic conventions of narrative, bringing forth the themes of anguish, alienation from the world and escape into the prison like realm of the self. The study follows roughly the Lacanian process of becoming a subject. Each chapter opens up with a quick introduction to the Lacanian concepts used in the following part that analyses the novels. The study can thus also be used as a brief introduction to Lacanian theory in finnish. The psychoanalytic narrative/story of the birth of the subject and the novels stories can be seen as mirroring each other. The method of the study is thus based on a dialogue between the theoretical concepts and the analyses. Novels are being approached as texts that break with the Cartesian notion of an autonomous subject making room for a dialectics of self and other, for a movement in which the “I” builds an identity mirroring itself with others. While both of the novels recount the birth of a character called I, they also have a first person narrator apart from the character “I”. Having constituted the self’s identity, the narrator finds from inside of the self also an other or “you” – this discovery is the final clue to the coffin of the autonomous self. From the Lacanian perspective man’s great Other is the order of language, Symbolic, which constitutes the individual, the speaking subject. Using this perspective the novels are interpreted as describing the process of becoming a subject of the Symbolic; subjected to Symbolic order. This “birth process” happens in particular in the Imaginary register, where the self’s identity is built. In the Imaginary or Mirror phase the “I” mirrors himself with different others (e.g. with his mirror image and the family members, the surrounding others) learning to see his body and his selfhood both as familiar and strange, other. In the Imaginary phase the novels’ characters are also trying to deal with the opposite realm of the Symcolic, the Real. The Lacanian Real is not the reality “before words” but a reality left over from the Symbolic, aside of it but constituted by the Symbolic, to be deducted only from within it. In the novels the Real is experienced as a womblike state where the self is immersed in the other’s body. The process of coming a subject of the Symbolic is depicted also as a process of renouncing the “dream of the womb”, which, if realized, could only mean the non-existence of the subject, i.e. death. The study concentrates on analysing the novels’ writing, where meanings are constantly changing: “I” becomes you, the father becomes a mother, inside becomes outside. This technique enables also the deconstruction of certain opposing notions in the novels. The Lacanian point of view exposes language as a constantly moving universe where the subject has no more stability than the momentary meanings language creates. The self’s identity depicted in the novels is a Lacanian fixed identity, whose growth is necessary but opposes the flux imminent to the Symbolic. The anguish experienced in the novels, in the “house of incest” or “inside”, is due to clinging on the unchanging “I”. However, the writing of the novels shows how the meaning of the “I” changes constantly and the fixity thus becomes movement. This way House of Incest and Dedans, despite their pessimistic stories, manage to create an image of a new, moving subject.
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The genus Quambalaria consists of plant-pathogenic fungi causing disease on leaves and shoots of species of Eucalyptus and its close relative, Corymbia. The phylogenetic relationship of Quambalaria spp., previously classified in genera such as Sporothrix and Ramularia, has never been addressed. It has, however, been suggested that they belong to the basidiomycete orders Exobasidiales or Ustilaginales. The aim of this study was thus to consider the ordinal relationships of Q. eucalypti and Q. pitereka using ribosomal LSU sequences. Sequence data from the ITS nrDNA were used to determine the phylogenetic relationship of the two Quambalaria species together with Fugomyces (= Cerinosterus) cyanescens. In addition to sequence data, the ultrastructure of the septal pores of the species in question was compared. From the LSU sequence data it was concluded that Quambalaria spp. and F. cyanescens form a monophyletic clade in the Microstromatales, an order of the Ustilaginomycetes. Sequences from the ITS region confirmed that Q. pitereka and Q. eucalypti are distinct species. The ex-type isolate of F. cyanescens, together with another isolate from Eucalyptus in Australia, constitute a third species of Quambalaria, Q. cyanescens (de Hoog & G.A. de Vries) Z.W. de Beer, Begerow & R. Bauer comb. nov. Transmission electron-microscopic studies of the septal pores confirm that all three Quambalaria spp. have dolipores with swollen lips, which differ from other members of the Microstromatales (i.e. the Microstromataceae and Volvocisporiaceae) that have simple pores with more or less rounded pore lips. Based on their unique ultrastructural features and the monophyly of the three Quambalaria spp. in the Microstromatales, a new family, Quambalariaceae Z.W. de Beer, Begerow & R. Bauer fam. nov., is described.
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In this paper, we present results on water flow past randomly textured hydrophobic surfaces with relatively large surface features of the order of 50 µm. Direct shear stress measurements are made on these surfaces in a channel configuration. The measurements indicate that the flow rates required to maintain a shear stress value vary substantially with water immersion time. At small times after filling the channel with water, the flow rates are up to 30% higher compared with the reference hydrophilic surface. With time, the flow rate gradually decreases and in a few hours reaches a value that is nearly the same as the hydrophilic case. Calculations of the effective slip lengths indicate that it varies from about 50 µm at small times to nearly zero or “no slip” after a few hours. Large effective slip lengths on such hydrophobic surfaces are known to be caused by trapped air pockets in the crevices of the surface. In order to understand the time dependent effective slip length, direct visualization of trapped air pockets is made in stationary water using the principle of total internal reflection of light at the water-air interface of the air pockets. These visualizations indicate that the number of bright spots corresponding to the air pockets decreases with time. This type of gradual disappearance of the trapped air pockets is possibly the reason for the decrease in effective slip length with time in the flow experiments. From the practical point of usage of such surfaces to reduce pressure drop, say, in microchannels, this time scale of the order of 1 h for the reduction in slip length would be very crucial. It would ultimately decide the time over which the surface can usefully provide pressure drop reductions. ©2009 American Institute of Physics