Physical-Chemical Properties of Strawberry Pseudofruits Submitted to Applications of Zinc Oxide Nanoparticles

Strawberry cultivation is appreciated in many countries because of the fruit's well-defined, attractive and nutritional sensorial characteristics. As such, it is of great commercial value. The flavor and nutritional properties of the fruit are characteristics that have been developed and gaining importance, both in breeding programs and in productive systems. In this sense, this work proposes the application of nanotechnology for the improvement of the physicochemical characteristics of strawberry crops, with the main objective of analyzing the influence on nutritional performance of different fruit treatment doses with zinc oxide nanoparticles. The physicochemical analyses of the strawberry pseudofruitswere carried out from November to June 2016. The experimental design was in randomized complete blocks, in a factorial scheme, with 7 replicates. The collected data were submitted to analysis of variance with the F-test and the differences between means were compared by the Tukey test (P≤0.05).The treatment process of the strawberry crop with zinc oxide nanoparticles was shown to be efficient for anthocyanin nutrients and soluble solids. The method for analyzing vitamin C, which consisted in freezing the raw material, was ineffective, probably because of the reduction of ascorbic acid levels by the freezing and crystallization of the sample. Climatic factors significantly influence the nutritional composition of anthocyanins and soluble solids. The application of nanoparticles at 100% of the recommended dose proved to be more effective than zinc oxide in its natural form in increasing the soluble solids values

Physical and Mechanical Properties of Three Polystyrene Impregnated Indonesian Wood Species

The disadvantage of fast-growing species is that they have inferior physical and mechanical properties. Polystyrene impregnation can be applied to improve physical and mechanical properties. Wood samples, which were dried until 10% moisture content were put into impregnating tank and vacuum pressured at 20-mm Hg for two hours. During the gradual release of vacuum, styrene monomers, vinyl acetate monomers and terburyl-peroxide catalyst was streamed into the tank. Afterwards, the pressure inside the tank was allowed to decrease to 500 mm Hg and kept for 60 minutes. Wood samples which had been impregnated were subsequently immersed in water, then wrapped in aluminum foils and put in the oven for 24 hours at 60°C. The samples were then tested for the polymer loading and their physical and mechanical properties. The results showed that the polymer loadings in wood plastics with the species of origin (i.e. consecutively sengon, pine and rubber wood) were 118%, 72% and 44%, respectively. Impregnation with polystyrene (copolymer of styrene and vinyl acetate monomers) could improve the physical and mechanical properties of wood plastics, i.e. specific gravity, moisture content, water absorption, shrinkage/ swelling, compression parallelto the wood grain, MOR and MOE. Greater use of vinyl acetate decreased physical and mechanical properties

Physical Properties of (2) Pallas

We acquired and analyzed adaptive-optics imaging observations of asteroid (2) Pallas from Keck II and the Very Large Telescope taken during four Pallas oppositions between 2003 and 2007, with spatial resolution spanning 32-88 km (image scales 13-20 km/pix). We improve our determination of the size, shape, and pole by a novel method that combines our AO data with 51 visual light-curves spanning 34 years of observations as well as occultation data. The shape model of Pallas derived here reproduces well both the projected shape of Pallas on the sky and light-curve behavior at all the epochs considered. We resolved the pole ambiguity and found the spin-vector coordinates to be within 5 deg. of [long, lat] = [30 deg., -16 deg.] in the ECJ2000.0 reference frame, indicating a high obliquity of ~84 deg., leading to high seasonal contrast. The best triaxial-ellipsoid fit returns radii of a=275 km, b= 258 km, and c= 238 km. From the mass of Pallas determined by gravitational perturbation on other minor bodies [(1.2 +/- 0.3) x 10-10 Solar Masses], we derive a density of 3.4 +/- 0.9 g.cm-3 significantly different from the density of C-type (1) Ceres of 2.2 +/- 0.1 g.cm-3. Considering the spectral similarities of Pallas and Ceres at visible and near-infrared wavelengths, this may point to fundamental differences in the interior composition or structure of these two bodies. We define a planetocentric longitude system for Pallas, following IAU guidelines. We also present the first albedo maps of Pallas covering ~80% of the surface in K-band. These maps reveal features with diameters in the 70-180 km range and an albedo contrast of about 6% wrt the mean surface albedo.Comment: 16 pages, 8 figures, 6 table

Physical limits to sensing material properties

Constitutive relations describe how materials respond to external stimuli such as forces. All materials respond heterogeneously at small scales, which limits what a localized sensor can discern about the global constitution of a material. In this paper, we quantify the limits of such constitutional sensing by determining the optimal measurement protocols for sensors embedded in disordered media. For an elastic medium, we find that the least fractional uncertainty with which a sensor can determine a material constant $\lambda_0$ is approximately \begin{equation*} \frac{\delta \lambda_0}{\lambda_0 } \sim \left( \frac{\Delta_{\lambda} }{ \lambda_0^2} \right)^{1/2} \left( \frac{ d }{ a } \right)^{D/2} \left( \frac{ \xi }{ a } \right)^{D/2} \end{equation*} for $a \gg d \gg \xi$, $\lambda_0 \gg \Delta_{\lambda}^{1/2}$, and $D>1$, where $a$ is the size of the sensor, $d$ is its spatial resolution, $\xi$ is the correlation length of fluctuations in the material constant, $\Delta_{\lambda}$ is the local variability of the material constant, and $D$ is the dimension of the medium. Our results reveal how one can construct microscopic devices capable of sensing near these physical limits, e.g. for medical diagnostics. We show how our theoretical framework can be applied to an experimental system by estimating a bound on the precision of cellular mechanosensing in a biopolymer network.Comment: 33 pages, 3 figure

Physical properties of 6dF dwarf galaxies

Spectral synthesis is basically the decomposition of an observed spectrum in terms of the superposition of a base of simple stellar populations of various ages and metallicities, producing as output the star formation and chemical histories of a galaxy, its extinction and velocity dispersion. The STARLIGHT code provides one of the most powerful spectral synthesis tools presently available. We have applied this code to the entire Six-Degree-Field Survey (6dF) sample of nearby star-forming galaxies, selecting dwarf galaxy candidates with the goal of: (1) deriving the age and metallicity of their stellar populations and (2) creating a database with the physical properties of our sample galaxies together with the FITS files of pure emission line spectra (i.e. the observed spectra after subtraction of the best-fitting synthetic stellar spectrum). Our results yield a good qualitative and quantitative agreement with previous studies based on the Sloan Digital Sky Survey (SDSS). However, an advantage of 6dF spectra is that they are taken within a twice as large fiber aperture, much reducing aperture effects in studies of nearby dwarf galaxies.Comment: To appear in JENAM Symposium "Dwarf Galaxies: Keys to Galaxy Formation and Evolution", P. Papaderos, S. Recchi, G. Hensler (eds.). Lisbon, September 2010, Springer Verlag, in pres

Response of hydro-physical properties of a Chromic Luvisol in Ghana to different methods of application of Mucuna pruriens as a soil amendments

The study assessed the response of hydro-physical properties of Chromic Luvisol to different methods of application of Mucuna pruriens as a soil amendments in two separate experiments. A Randomized Complete Block Design (RCBD) with three replications was used with the following treatments: 7.04t/ha Mucuna pruriens as green manure (GM), 7.04t/ha Mucuna pruriens as live mulch (LM), 7.04t/ha Mucuna pruriens as in-situ mulch (IM) and a control plot which had no Mucuna pruriens as soil amendment. Data were collected on gravimetric (θ_g) and volumetric moisture content ( θ_v), residual moisture storage(R), sorptivity(s), cumulative infiltration (I), bulk density (ρ_b), total porosity (f), aeration porosity (ξ_a), aggregate stability (ASt) and soil temperature, for assessment of hydro-physical properties of the soil. The results from the experiments indicated that Mucuna pruriens as live mulch used as amendment significantly reduce bulk density (ρ_b), increased total porosity (f) and aeration porosity (ξ_a) thus it gave significant improvement on those soil physical properties measured while Mucuna pruriens as in-situ mulch improved aggregate stability (ASt) and gave optimal soil temperature. In the assessment of soil volumetric moisture content ( θ_v), residual moisture storage(R), sorptivity(s), cumulative infiltration(I), the study shows that Mucuna pruriens as in-situ mulch recorded the optimal values and was closely followed by Mucuna pruriens as live mulch