1,214 research outputs found

    Tin(iv) Phosphonates With α-layered Structure: Synthesis And Characterization

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    The synthesis of layered compounds of the general formula Sn(RPO 3)2·xH2O (R = phenyl, 2-carboxyethyl) and Sn(RPO3)2·xH2O (R = dodecyl) are reported. These compounds are formed by the reaction of nitric solutions of SnCl4 with the phosphonic acid or phosphoric ester followed by heating under reflux. The interlayer distances of 13.87, 15.37 and 32.70 Å for 2-carboxyethyl, phenyl and dodecyl derivatives, respectively, are determined by the XRD patterns. A linear relationship between the molar volume and the interlayer distance is observed suggesting an alpha structure similar to α-Sn(RPO4)2·H2O. FTIR spectra show the formation of an Sn- O-P skeleton.2101075107

    Susceptibility of adults of the cerambycid beetle Hedypathes betulinus to the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Purpureocillium lilacinum

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    Fil: Schapovaloff, M.E.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores; ArgentinaFil: Alves, L.F.A.. Universidade Estadual do Oeste do Paraná. Laboratório de Biotecnologia Agrícola; BrasilFil: Fanti, A.L.. Universidade Estadual do Oeste do Paraná. Laboratório de Biotecnologia Agrícola; BrasilFil: Alzogaray, R.A.. Centro de Investigaciones de Plagas e Insecticidas; ArgentinaFil: López Lastra, Claudia Cristina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores; Argentin

    Dry‐Cured Meat Products According to the Smoking Regime: Process Optimization to Control Polycyclic Aromatic Hydrocarbons

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    The manufacturing of dry‐cured meat products usually includes a smoking step. Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic chemical compounds that may result from smoking. The aim of the present study was to optimize the smoking regime of traditional dry‐cured meat products in order to minimize the presence of PAHs. Dry‐cured sausages were submitted to different smoking regimes: (A) no smoking; (B) 20 h effective smoking; (C) 60 h effective smoking; (D) effective smoking until reaching 38%–40% weight losses. Three independent batches were produced per smoking regime, and three samples per batch were analyzed. Microbiological, physicochemical, and sensory analyses were performed. The total PAHs content was generally low and did not differ significantly in meat products submitted to the four different smoking regimes. The PAH4 and benzo(α)pyrene levels were below the established legal limits in all analyzed dry‐cured sausages. Nevertheless, non‐smoked sausages always showed lower PAHs values for all PAHs groups

    Properties of Interfaces in the two and three dimensional Ising Model

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    To investigate order-order interfaces, we perform multimagnetical Monte Carlo simulations of the 2D2D and 3D3D Ising model. Following Binder we extract the interfacial free energy from the infinite volume limit of the magnetic probability density. Stringent tests of the numerical methods are performed by reproducing with high precision exact 2D2D results. In the physically more interesting 3D3D case we estimate the amplitude F0sF^s_0 of the critical interfacial tension Fs=F0stμF^s = F^s_0 t^\mu to be F0s=1.52±0.05F^s_0 = 1.52 \pm 0.05. This result is in good agreement with a previous MC calculation by Mon, as well as with experimental results for related amplitude ratios. In addition, we study in some details the shape of the magnetic probability density for temperatures below the Curie point.Comment: 25 pages; sorry no figures include

    Alterações Físicas Em Latossolos Cultivados Com Plantas De Cobertura Em Rotação Com Soja E Milho

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    This study was conducted to evaluate the effect of different covers, grown in rotation with soybean and corn on the physical attributes of two Oxisols. The experiments were installed in Votuporanga, SP, Brazil and Selvíria, MS, Brazil in March 2008, after conventional tillage. The experimental design was a randomized complete block with four replications, using the following cover crops at different amounts of seeds: Sorghum bicolor, Pennisetum americanum, S. sudanense, hybrid of S. bicolor with S. sudanense, Urochloa ruziziensis and a control with spontaneous vegetation. We evaluated the dry matter yield of different covers, and macroporosity, microporosity, total porosity and bulk density, in the layers of 0-0.05, 0.05-0.20 and 0.20-0.40 m. It concludes that, different covers plants and seed amounts used for grains, seeds and forage after two years did not cause effects on some soil physical properties of the two Oxisols.11314915

    Estabilidade De Agregados Em Latossolos Sob Plantas De Cobertura Em Rotação Com Soja E Milho

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    The objective was to evaluate the effect of different covers on the stability of soil aggregates in two areas of Oxisols, grown in rotation with crops of soybean and corn. The experiments were installed in Votuporanga, São Paulo, Brazil and Selvíria, Mato Grosso do Sul, Brazil in March 2008. The experimental design was a randomized block with four replicates and the following cover crops in different spending ha-1 seeds, were the treatments: Sorghum bicolor, 6, 7 and 8 kg ha-1; Pennisetum americanum, 10, 15 and 20 kg ha-1; S. sudanense, 12, 15 and 18 kg ha-1; hybrid of S. bicolor and S. sudanense, 8, 9 and 10 kg ha-1; Urochloa ruziziensis, 8, 12 and 16 kg ha-1; plus, control treatment with spontaneous vegetation. We evaluated the dry matter yield of different covers and were separate classes of soil aggregates and calculated the average diameter. It is noted that the cover crops had similar behavior on aggregates stability in the surface layer, and in the greater depth, the S. sudanense was more efficient in improving the class mean diameter between 2.0-1.0 mm, in Votuporanga, and the P. americanum was more efficient from 4.0 to 2.0 mm and 2.0-1.0 mm in Selvíria. Lower spending seeds was more promising on aggregate stability.11315616

    A Note on Energy-Momentum Conservation in Palatini Formulation of L(R) Gravity

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    By establishing that Palatini formulation of L(R)L(R) gravity is equivalent to ω=3/2\omega=-3/2 Brans-Dicke theory, we show that energy-momentum tensor is covariantly conserved in this type of modified gravity theory.Comment: 7 page

    Urinary schistosomiasis in Guinea Bissau

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    Urogenital schistosomiasis due to Schistosoma (S.) haematobium is among the most prevalent parasitoses in sub-Saharan Africa. The pathology is characterized by serious and irreversible lesions in the urogenital tract induced by chronic infection with the parasite that can eventually lead to renal failure due to hydronephrosis and to squamous cell carcinoma of the bladder. Considering the frequency and severe morbidity observed already in young children, the purpose of this pilot study was to assess the prevalence and morbidity of S. haematobium infection in Guinea Bissau. A baseline survey was conducted during September 2011. A randomly selected sample of 90 children aged 6–15 years old was included in this study. Prevalence of S. haematobium infection was 20% (18/90). It was higher in older children (median age in years: 15.4 2.71 vs. 9.3 2.22; P < 0.001), a significant gender difference in prevalence and intensity was not found. The predominant symptom was haematuria (87.1%), this symptom being strongly associated with S. haematobium infection (P < 0.01). Anthropometric examination revealed that growth in infected boys was impaired as compared to non-infected boys (median height in cm: 123.3 21.07 vs. 134.71 15.1) (P < 0.05). To our knowledge this is the first epidemiologic report of S. haematobium infection in Guinea Bissau. Considering the high prevalence of S. haematobium infections in Guinea Bissau and the long-term risks, including renal failure and bladder cancer, our results indicate that this population should be targeted for follow-up and implementation of measures for treatment and control of schistosomiasis

    A model independent spin analysis of fundamental particles using azimuthal asymmetries

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    Exploiting the azimuthal angle dependence of the density matrices we construct observables that directly measure the spin of a heavy unstable particle. A novelty of the approach is that the analysis of the azimuthal angle dependence in a frame other than the usual helicity frame offers an independent cross-check on the extraction of the spin. Moreover, in some instances when the transverse polarisation tensor of highest rank is vanishing, for an accidental or dynamical reason, the standard azimuthal asymmetries vanish and would lead to a measurement with a wrong spin assignment. In a frame such as the one we construct, the correct spin assignment would however still be possible. The method gives direct information about the spin of the particle under consideration and the same event sample can be used to identify the spins of each particle in a decay chain. A drawback of the method is that it is instrumental only when the momenta of the test particle can be reconstructed. However we hope that it might still be of use in situations with only partial reconstruction. We also derive the conditions on the production and decay mechanisms for the spins, and hence the polarisations, to be measured at a collider experiment. As an example for the use of the method we consider the simultaneous reconstruction, at the partonic level, of the spin of both the top and the WW in top pair production in e+ee^+ e^- in the semi-leptonic channel.Comment: 42 pages, 7 figures, 4 table
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